title: German colonial empire

text: Chancellor Adolf Hitler's speeches sometimes did mention return of the lost colonies, as a bargaining point, but at all times his real target was Eastern Europe. In 1934, the Nazi party established its own Office of Colonial Policy, which was led by Heinrich Schnee, and then Franz Ritter von Epp and was a very active grass roots organisation. The Reichskolonialbund, established in 1936, under Franz Ritter von Epp absorbed all colonial organizations and was meant to raise pro-colonial sentiments, and build public interest in former German colonies. However, no new overseas colonial enterprises took place and with the onset of World War II in 1939 the organization entered a decline. It was disbanded by decree in 1943 for "activity irrelevant to the war". Although it tolerated the colonialists, the Nazi government focused on territorial gains inside Europe. At no time did it negotiate or demand from London or Paris the return of any lost colony. According to Willeke Sandler: "Between 1933 and 1943, Rudolf Hess, Martin Borman, and Joachim von Ribbentrop, among others, hindered colonialists' publicity activities, seeing them as representative of a discarded past and as irrelevant when compared with Eastern European 'Lebensraum.'"


title: German colonial empire

text: The former German colonies played no role in the politics of Post-war Germany. However, individual west German politicians proposed undertaking late or post-colonial enterprises, especially the management of trusts in Tanganyika or Togo. Even within the African freedom movement, these suggestions co-existed with calls for decolonisation. At the end of 1952, members of the Ewe people submitted in a memorandum to the United Nations Trusteeship Council proposing that the territories of German Togoland taken by the British and the French be reunited and led towards independence together. This initiative was not accepted. In 1960, Adolf Friedrich zu Mecklenburg, the final German governor of Togo, was invited to Togo's independence celebrations by Sylvanus Olympio, President of Togo.


title: German colonial empire

text: Efforts to revive the Colonial War League after the Second World War, led to the establishment in Hamburg in 1955 of a "Union of Former Colonial Troops," ancestor of the current .


title: German colonial empire

text: The final remains of the Protectorate Law survived until the legal expiration of the Colonial Society in 1975 and fiscal adjustments in 1992. Colonial history continues to be commemorated by colonial monuments, street names, and buildings related to German colonial history. In many places this has led to discussions about cultural memory and to calls for modification or renaming.


title: German colonial empire

text: Representatives of the Herero and Nama, whose ancestors were killed in their thousands in German-administered Southwest Africa between 1904 and 1908, having taken legal action against Germany in the American courts. In January 2017, a class action against the German government was submitted to a court in New York. The statement of claim speaks of over 100,000 fatalities. In March 2017, it became known that the Namibian government was considering an action against Germany in the International Court of Justice in The Hague. It was said that damages were sought in the region of 30 billion dollars.


title: German colonial empire

text: The publication of edited volumes on the themes of colonialism (2012) and German Colonial History (2019) by the Federal Agency for Civic Education aimed to bring about "revived awareness of colonialism in political, legal, and psycological spheres" to a wider group of readers and scholars, as the editor Asiye Öztürk put it. In 2015, Heinrich Heine University in Düsseldorf and the University of Dschang in Cameroon established a joint-research project on "Colonial links", which culminated in an exhibition in Düsseldorf in 2017. After that, the exhibition travelled to Dschang and to various German cities, where it was augmented with aspects of local relevance. Finally, a volume on the exhibition was published in 2019.


title: German colonial empire

text: Between 1890 and 1907, the uppermost leadership of the empire's protectorates ("Schutzgebiete") was the Colonial Division ("Kolonialabteilung") of the Foreign Office ("Auswärtiges Amt"), which was headed by the Imperial Chancellor. In 1907, the Colonial Division was separated from the Foreign Office and became its own ministry ("Amt"), called the Imperial Colonial Office ("Reichskolonialamt"), with Bernhard Dernburg as its state secretary.


title: German colonial empire

text: By an Imperial decree of 10 October 1890, the Colonial Council ("Kolonialrat") was placed alongside the Colonial Division. It contained representatives of the Colonial Societies and experts appointed by the Chancellor.


title: German colonial empire

text: The German treaty port of Kiautschou was administered by the Imperial Naval Office ("Reichsmarineamt"), not the Foreign Office or the Colonial Office.


title: German colonial empire

text: The highest legal authority for the colonies was the Reichsgericht (Imperial Court of Justice) in Leipzig.


title: German colonial empire

text: The legal situation in the colonies was first regulated by the 1886 law concerning the legal relationships of the German protectorates, which became the ("Schutzgebietsgesetz") in 1900 after further changes. It introduced German law in the German colonies for Europeans, through consular jurisdiction. The Consular Jurisdiction Law ("Konsulargerichtsbarkeitsgesetz ") of 1879 had granted German consuls overseas jurisdiction over German citizens in specific circumstances. The Protectorate Law specified that the regulations on consular jurisdiction would also apply in the colonies. In so far as they were relevant to consular jurisdiction, therefore, various important legal provisions of civil law, criminal law, legal procedure, and due process also came into force in the colonies. Alongside this, over time, further special provisions of colonial law were established. For indigenous people in the colonies, the Kaiser was initially held all legislative power. Over the following years, the Imperial Chancellor and other officials empowered by him were also given the authority to regulate the administration, jurisdiction, policing, etc. of the colonies. Thus, in the German colonies there was, at a fundamental level, a dual legal structure, with different laws for the Europeans and the indigenous people. No colonial criminal law code was codified during German colonial rule.


title: German colonial empire

text: At the top of the administration of each colony was the Governor, who was aided by a chancellor (as deputy and assistance in legal matters), secretaries, and other officials.


title: German colonial empire

text: The districts ("Bezirke"), the largest administrative subdivisions of a colony, were administered by a District Officer ("Bezirksamtmann"). In turn, a district was divided into district branches ("Bezirksnebenstellen"). Another form of administration in the colonies was the Resident ("Residentur"). These were comparable to the districts in size, but the native rulers were allowed far more power in residencies than in districts, helping to keep the costs of German administration as low as possible.


title: German colonial empire

text: Schutztruppen were stationed in the colonies of Cameroon, Southwest Africa, and East Africa for internal military security. The police forces in the colonies were police troops ("Polizeitruppen"), organised on military lines. In the Kiautschou Leased Bay Territory, which was under the control of the German Imperial Naval Office, marines of the 3rd Sea Batillion were stationed as police.


title: German colonial empire

text: In the colonies, there were Protectorate Courts ("Schutzgebietsgerichte"), modelled on consular courts. Jurisdiction over indigenous peoples, especially in criminal cases, was invested in the colonial officials in the colonies. In non-criminal matters, indigenous authorities were granted jurisdiction over their communities and could render judgment in accordance with local law.


title: German colonial empire

text: For Germans and other Europeans, the district court ("Bezirksgericht") had jurisdiction in first instance and there was a right of appeal to an upper court ("Obergericht"). In Togo, the size of the European population made an upper court impractical, so the upper court of Kamerun also acted as the appellate court for Togo.


title: German colonial empire

text: The Pennsylvania Dutch who emigrated to America in the 17th and 18th centuries were religious refugees from the Thirty Years War which devastated the German states 1616-1648 rather than colonial settlers. Germantown, Pennsylvania, was founded in 1684 and 65,000 Germans landed in Philadelphia alone between 1727 and 1775, and more at other American ports. More than 950,000 Germans immigrated to the US in the 1850s and 1,453,000 in the 1880s, but these were personal migrants, unrelated to the German Empire (created 1871) and later colonial plans. The Empire's colonies were primarily commercial and plantation regions and did not attract large numbers of German settlers. The vast majority of German emigrants chose North America as their destination and not the colonies – of 1,085,124 emigrants between 1887 and 1906, 1,007,574 headed to the United States. When the imperial government invited the 22,000 soldiers mobilized to subdue the Hereros to settle in German South-West Africa, and offered financial aid, only 5% accepted.


title: German colonial empire

text: The German colonial population numbered 5,125 in 1903, and about 23,500 in 1913. The German pre–World War I colonial population consisted of 19,696 Germans in Africa and the Pacific colonies in 1913, including more than 3,000 police and soldiers, and 3,806 in Kiaochow (1910), of which 2,275 were navy and military staff. In Africa (1913), 12,292 Germans lived in Southwest Africa, 4,107 in German East Africa and 1,643 in Cameroon. In the Pacific colonies in 1913 there were 1,645 Germans. After 1905 a ban on marriage was enacted forbidding mixed couples between German and native population in South-West Africa, and after 1912 in Samoa.


title: German colonial empire

text: After World War I, the military and "undesired persons" were expelled from the German protectorates. In 1934 the former colonies were inhabited by 16,774 Germans, of whom about 12,000 lived in the former Southwest African colony. Once the new owners of the colonies again permitted immigration from Germany, the numbers rose in the following years above the pre–World War I total.


title: German colonial empire

text: The relationship between the Germans and the indigenous populations in the German colonies was characterised by legal and social inequality, as in all the other colonial empires. There were two separate legal systems and people were assigned to one or the other on the basis of racial criteria. The "whites" (i.e. the German and European inhabitants of the colonies) formed a small, highly privileged minority - rarely reaching even 1% of a colony's total population. They enjoyed all the rights, privileges, and duties of normal German law. Non-German Europeans were legally their equals.


title: German colonial empire

text: The 13 million or so "natives" of the German colonial empire did not become German citizens in 1913, when German citizenship was first introduced. They were not considered Imperial citizens, but only subjects or wards of Germany. German laws applied to them only if explicitly stated by the individual statute. In particular, they were shut out of the court system. They had no right of appeal against decisions of the colonial authorities or first-instance judgements. For the 10,000 or so people of Arab and Indian descent who lived in German East Africa, the governors had the ability to issue special regulations. According the Protectorate Law, however, it was possible for "natives" to be granted Imperial citizenship and to pass that citizenship on to their children. The cause of this was the fact that the children of mixed marriages automatically received German citizenship. This was perceived as a threat to the "German body politic" and its "racial purity." As sexual relationships between the population groups had grown increasingly common, the colonies gradually banned "civil marriage between whites and natives" from 1905. Extra-marital sexual relationships were socially unacceptable, as leading to "Kaffir-isation" ("Verkaffirung"). In 1912, the Reichstag held a debate about the possibility of miscegenation, resulting in most parties agreeing that miscegenation should be legalised. However, no law on this was ever enacted. The ban remained in effect until the end of the German Empire.


title: German colonial empire

text: The German colonisers conceived of the indigenous populations as "children": people at a lower level of development, who had to be protected, educated, and raised up. German missionary societies were already concerning themselves with the education and conversion of overseas populations in the 1820s. Protestant organisations included the Berlin Missionary Society, Rhenish Missionary Society, , and the North German Missionary Society. After the Kulturkampf had subsided, Catholic missionary societies were allowed to operate in the colonies too.


title: German colonial empire

text: These missionary societies established stations in the colonies, where they instructed the indigenous people in basic education, modern agricultural techniques, and Christianity. They had substantial success, since the breakdown of pre-colonial society, which the German land seizures and colonial wars had engendered, often brought a spiritual crisis with it and the indigenous people sought comfort and support from the god of the new rulers, who appeared to have proven his superiority. Since the goal of the missionaries was the conversion of the indigenous peoples and they emphasised the virtue of neighbourly love, they often had cause to protest against their abuse and exploitation by the colonial administration and plantation owners. In order to support themselves and to model good behaviour, the missionaries themselves often had plantations, which were dependent on the indigenous people's skill and willingness to work. These goals often came into conflict. The missionaries were generally rather tolerant regarding traditional customs and practices. For example, they often allowed polygamy, which was widespread in Africa and the Pacfic. The exception to this was the Islamic culture of the East African coast, which the missionaries strongly opposed.


title: German colonial empire

text: In her African and South Seas colonies, Germany established diverse biological and agricultural stations. Staff specialists and the occasional visiting university group conducted soil analyses, developed plant hybrids, experimented with fertilizers, studied vegetable pests and ran courses in agronomy for settlers and natives and performed a host of other tasks. Successful German plantation operators realized the benefits of systematic scientific inquiry and instituted and maintained their own stations with their own personnel, who further engaged in exploration and documentation of the native fauna and flora.


title: German colonial empire

text: Research by bacteriologists Robert Koch and Paul Ehrlich and other scientists was funded by the imperial treasury and was freely shared with other nations. More than three million Africans were vaccinated against smallpox. Medical doctors the world over benefited from pioneering work into tropical diseases and German pharmaceutical discoveries "became a standard therapy for sleeping sickness and relapsing fever. The German presence (in Africa) was vital for significant achievements in medicine and agriculture.


title: German colonial empire

text: By the late 1880s German physicians identified venereal disease as a public health threat to Germany and its colonies. To fight it in Germany doctors used biopolitics to educate and regulate the bodies of likely victims. Propaganda campaigns did not work well in the colonies, so they imposed a much greater degree of supervision and coercion over targeted groups such as prostitutes.


title: German colonial empire

text: During the Herero genocide Eugen Fischer, a German scientist, came to the concentration camps to conduct medical experiments on race, using children of Herero people and multiracial children of Herero women and German men as test subjects. Together with Theodor Mollison he also experimented upon Herero prisoners. Those experiments included sterilization, injection of smallpox, typhus as well as tuberculosis.


title: German colonial empire

text: The numerous cases of mixed offspring upset the German colonial administration, which was concerned with maintaining "racial purity". Eugen Fischer studied 310 multiracial children, calling them "Rehoboth bastards" of "lesser racial quality". Fischer also subjected them to numerous racial tests such as head and body measurements, and eye and hair examinations. In conclusion of his studies he advocated genocide of alleged "inferior races", stating that "whoever thinks thoroughly the notion of race, can not arrive at a different conclusion".


title: German colonial empire

text: Fischer's actions (at the time considered) scientific and his torment of the children were part of a wider history of abusing Africans for experiments, and echoed earlier actions by German anthropologists who stole skeletons and bodies from African graveyards and took them to Europe for research or sale. An estimated 3000 skulls were sent to Germany for study. In October 2011, after 3 years of talks, the first skulls were due to be returned to Namibia for burial.


title: German colonial empire

text: Other experiments were made by Doctor Bofinger, who injected Herero who were suffering from scurvy with various substances including arsenic and opium. Afterwards he researched the effects of these substances by performing autopsies on dead bodies.


title: German colonial empire

text: Social Darwinism is the theory "that human groups and races are subject to the same laws of natural selection as Charles Darwin had perceived in plants and animals in nature." According to numerous historians, an important ideological component of German nationalism as developed by the intellectual elite was Social Darwinism. It gave an impetus to German assertiveness as a world economic and military power, aimed at competing with France and the British Empire for world power. German colonial rule in Africa 1884-1914 was an expression of nationalism and moral superiority that was justified by constructing an image of the natives as "Other". German colonization was characterized by the use of repressive violence in the name of 'culture' and 'civilization'. Techniques included genocide in parts of Africa. Furthermore, the wide acceptance among intellectuals of social Darwinism justified Germany's right to acquire colonial territories as a matter of the 'survival of the fittest', according to historian Michael Schubert.


title: German colonial empire

text: On the other hand, Germany's cultural-missionary project boasted that its colonial programs were humanitarian and educational endeavors. Colonial German physicians and administrators tried to make a case for increasing the native population, in order to also increase their numbers of laborers. Eugene Fischer, an anthropologist at the University of Freiburg, agreed with that notion saying that they should only be supported as necessary and as they prove to be useful. Once their use is gone Europeans should, "allow free competition, which in my (Fischer's) opinion means their demise." .


title: German colonial empire

text: The Dualas, a Bantu group in Cameroon readily welcomed German policies The number of German-speaking Africans increased in four West African German colonies prior to 1914. The Duala leadership in 1884 placed the tribe under German rule. Most converted to Protestantism and were schooled educated along German lines. Colonial officials and businessmen preferred them as inexpensive clerks to German government offices and firms in Africa.


title: German colonial empire

text: In recent years scholars have debated the "continuity thesis" that links German colonialist brutalities to the treatment of Jews, Roma, Poles and Russians during World War II. Some historians argue that Germany's role in southwestern Africa gave rise to an emphasis on racial superiority at home, which in turn was used by the Nazis. They argue that the limited successes of German colonialism overseas led to a decision to shift the main focus of German expansionism into Central and Eastern Europe, with the Mitteleuropa plan. German colonialism, therefore, turned to the European continent.


title: German colonial empire

text: While a minority view during the "Kaiserzeit", the idea developed in full swing under Erich Ludendorff and his political activity in the Baltic states, Ukraine, and Poland. Subsequently, after the defeat of Russia during World War I, Germany acquired vast territories with the Treaty of Brest-Litovsk and created several administrative regions like Ober Ost. Here also the German settlement would be implemented, and the whole governmental organization was developed to serve German needs while controlling the local ethnically diverse population. While the African colonies were too isolated and not suitable for mass settlement of Germans, areas in Central and Eastern Europe offered better potential for German settlement. Other scholars, are skeptical and challenge the continuity thesis. Additionally, however, only one former colonial officer gained an important position in the Nazi administrative hierarchy.


title: German colonial empire

text: Unlike other colonial empires such as the British, French, Portuguese Empire or Spanish, Germany left very few traces of its own language, institutions or customs in its former colonies. As of today, no country outside Europe uses the German language as an official language, although in Namibia, German is a recognized national language and there are numerous German placenames and architectural structures in the country. A small German ethnic minority also resides in the country.


title: Yorkshire pudding

text: Yorkshire pudding is a baked pudding made from a batter of eggs, flour, and milk or water. A common British side dish, it is a versatile food that can be served in numerous ways depending on its ingredients, size, and the accompanying components of the meal. As a first course, it can be served with onion gravy. For a main course, it may be served with meat and gravy, and is part of the traditional Sunday roast, but can also be filled with foods such as bangers and mash to make a meal. Sausages can be added to make toad in the hole. The 18th-century cookery writer Hannah Glasse was the first to use the term "Yorkshire pudding" in print.


title: Yorkshire pudding

text: Yorkshire puddings are similar to popovers, an American light roll made from basically the same recipe, and to Dutch baby pancakes.


title: Yorkshire pudding

text: When wheat flour began to come into common use for making cakes and puddings, cooks in northern England (Yorkshire) devised a means of making use of the fat that dropped into the dripping pan to cook a batter pudding while the meat roasted. In 1737, a recipe for "a dripping pudding" was published in Sir Alexander William George Cassey's book "The Whole Duty of a Woman":


title: Yorkshire pudding

text: Similar instructions were published during 1747 in the book "The Art of Cookery made Plain and Easy" by Hannah Glasse, with the name 'Yorkshire pudding'. It was she who renamed the original version, known as Dripping Pudding, which had been cooked in England for centuries, although these puddings were much flatter than the puffy versions made in modern times. William Sitwell suggests that the pudding got the name 'Yorkshire' due to the region's association with coal and the higher temperatures this produced which helped to make the batter crisper.


title: Yorkshire pudding

text: Originally, the Yorkshire pudding was served as a first course with thick gravy to dull the appetite with the low-cost ingredients so that the diners would not eat so much of the more expensive meat in the next course. Because the rich gravy from the roast meat drippings was used with the first course, the main meat and vegetable course was often served with a parsley or white sauce. In poorer households, the pudding was often served as the only course. Using dripping, a simple meal was made with flour, eggs and milk. This was traditionally eaten with a gravy or sauce, to moisten the pudding.


title: Yorkshire pudding

text: The Yorkshire pudding is meant to rise. The Royal Society of Chemistry suggested in 2008 that "A Yorkshire pudding isn't a Yorkshire pudding if it is less than tall".


title: Yorkshire pudding

text: In a 2012 poll conducted by T-Mobile UK, the Yorkshire pudding was ranked tenth in a list of things people love about Britain.


title: Yorkshire pudding

text: Yorkshire pudding is baked by pouring a batter made from milk, flour and eggs into oiled and preheated baking pans (ramekins or muffin tins in the case of miniature puddings). A basic formula uses 200ml flour and 200ml milk with four eggs (also 200ml). Water produces a lighter, crisper, but less sweet pudding than using milk. They can also be baked in cast-iron frying pans or similar. A 1926 recipe involves covering the pudding with greaseproof paper to steam it and then serving it with jam, butter and sugar.


title: Yorkshire pudding

text: National Yorkshire Pudding Day has been celebrated on the first Sunday in February in Britain since 2007. It is celebrated on 13 October in the United States.


title: Neutron

text: The neutron is a subatomic particle, symbol or , which has a neutral (not positive or negative) charge, and a mass slightly greater than that of a proton. Protons and neutrons constitute the nuclei of atoms. Since protons and neutrons behave similarly within the nucleus, and each has a mass of approximately one atomic mass unit, they are both referred to as nucleons. Their properties and interactions are described by nuclear physics. Protons and neutrons are not elementary particles; each is composed of three quarks.


title: Neutron

text: The chemical properties of an atom are mostly determined by the configuration of electrons that orbit the atom's heavy nucleus. The electron configuration is determined by the charge of the nucleus, which is determined by the number of protons, or atomic number. The number of neutrons is the neutron number. Neutrons do not affect the electron configuration, but the sum of atomic and neutron numbers is the mass of the nucleus.


title: Neutron

text: Atoms of a chemical element that differ only in neutron number are called isotopes. For example, carbon, with atomic number 6, has an abundant isotope carbon-12 with 6 neutrons and a rare isotope carbon-13 with 7 neutrons. Some elements occur in nature with only one stable isotope, such as fluorine; Other elements occur with many stable isotopes, such as tin with ten stable isotopes, and some elements such as technetium have no stable isotope.


title: Neutron

text: The properties of an atomic nucleus depend on both atomic and neutron numbers. With their positive charge, the protons within the nucleus are repelled by the long-range electromagnetic force, but the much stronger, but short-range, nuclear force binds the nucleons closely together. Neutrons are required for the stability of nuclei, with the exception of the single-proton hydrogen nucleus. Neutrons are produced copiously in nuclear fission and fusion. They are a primary contributor to the nucleosynthesis of chemical elements within stars through fission, fusion, and neutron capture processes.


title: Neutron

text: The neutron is essential to the production of nuclear power. In the decade after the neutron was discovered by James Chadwick in 1932, neutrons were used to induce many different types of nuclear transmutations. With the discovery of nuclear fission in 1938, it was quickly realized that, if a fission event produced neutrons, each of these neutrons might cause further fission events, in a cascade known as a nuclear chain reaction. These events and findings led to the first self-sustaining nuclear reactor (Chicago Pile-1, 1942) and the first nuclear weapon (Trinity, 1945).


title: Neutron

text: Dedicated neutron sources like neutron generators, research reactors and spallation sources produce free neutrons for use in irradiation and in neutron scattering experiments. A free neutron spontaneously decays to a proton, an electron, and an antineutrino, with a mean lifetime of about 15 minutes. Free neutrons do not directly ionize atoms, but they do indirectly cause ionizing radiation, so they can be a biological hazard, depending on dose. A small natural "neutron background" flux of free neutrons exists on Earth, caused by cosmic ray showers, and by the natural radioactivity of spontaneously fissionable elements in the Earth's crust.


title: Neutron

text: An atomic nucleus is formed by a number of protons, "Z" (the atomic number), and a number of neutrons, "N" (the neutron number), bound together by the nuclear force. The atomic number determines the chemical properties of the atom, and the neutron number determines the isotope or nuclide. The terms isotope and nuclide are often used synonymously, but they refer to chemical and nuclear properties, respectively. Isotopes are nuclides with the same atomic number, but different neutron number. Nuclides with the same neutron number, but different atomic number, are called isotones. The atomic mass number, "A", is equal to the sum of atomic and neutron numbers. Nuclides with the same atomic mass number, but different atomic and neutron numbers, are called isobars.


title: Neutron

text: The nucleus of the most common isotope of the hydrogen atom (with the chemical symbol H) is a lone proton. The nuclei of the heavy hydrogen isotopes deuterium (D or H) and tritium (T or H) contain one proton bound to one and two neutrons, respectively. All other types of atomic nuclei are composed of two or more protons and various numbers of neutrons. The most common nuclide of the common chemical element lead, Pb, has 82 protons and 126 neutrons, for example. The table of nuclides comprises all the known nuclides. Even though it is not a chemical element, the neutron is included in this table.


title: Neutron

text: The free neutron has a mass of , or , or . The neutron has a mean square radius of about , or , and it is a spin-½ fermion. The neutron has no measurable electric charge. With its positive electric charge, the proton is directly influenced by electric fields, whereas the neutron is unaffected by electric fields. But the neutron has a magnetic moment, so the neutron is influenced by magnetic fields. The neutron's magnetic moment has a negative value, because its orientation is opposite to the neutron's spin.


title: Neutron

text: A free neutron is unstable, decaying to a proton, electron and antineutrino with a mean lifetime of just under 15 minutes (). This radioactive decay, known as beta decay, is possible because the mass of the neutron is slightly greater than that of the proton. The free proton is stable. However, neutrons or protons bound in a nucleus can be stable or unstable, depending on the nuclide. Beta decay, in which neutrons decay to protons, or vice versa, is governed by the weak force, and it requires the emission or absorption of electrons and neutrinos, or their antiparticles.


title: Neutron

text: Protons and neutrons behave almost identically under the influence of the nuclear force within the nucleus. The concept of isospin, in which the proton and neutron are viewed as two quantum states of the same particle, is used to model the interactions of nucleons by the nuclear or weak forces. Because of the strength of the nuclear force at short distances, the binding energy of nucleons is more than seven orders of magnitude larger than the electromagnetic energy binding electrons in atoms. Nuclear reactions (such as nuclear fission) therefore have an energy density that is more than ten million times that of chemical reactions. Because of the mass–energy equivalence, nuclear binding energies reduce the mass of nuclei. Ultimately, the ability of the nuclear force to store energy arising from the electromagnetic repulsion of nuclear components is the basis for most of the energy that makes nuclear reactors or bombs possible. In nuclear fission, the absorption of a neutron by a heavy nuclide (e.g., uranium-235) causes the nuclide to become unstable and break into light nuclides and additional neutrons. The positively charged light nuclides then repel, releasing electromagnetic potential energy.


title: Neutron

text: The neutron is classified as a "hadron", because it is a composite particle made of quarks. The neutron is also classified as a "baryon", because it is composed of three valence quarks. The finite size of the neutron and its magnetic moment both indicate that the neutron is a composite, rather than elementary, particle. A neutron contains two down quarks with charge −"e" and one up quark with charge +"e".


title: Neutron

text: Like protons, the quarks of the neutron are held together by the strong force, mediated by gluons. The nuclear force results from secondary effects of the more fundamental strong force.


title: Neutron

text: The story of the discovery of the neutron and its properties is central to the extraordinary developments in atomic physics that occurred in the first half of the 20th century, leading ultimately to the atomic bomb in 1945. In the 1911 Rutherford model, the atom consisted of a small positively charged massive nucleus surrounded by a much larger cloud of negatively charged electrons. In 1920, Ernest Rutherford suggested that the nucleus consisted of positive protons and neutrally charged particles, suggested to be a proton and an electron bound in some way. Electrons were assumed to reside within the nucleus because it was known that beta radiation consisted of electrons emitted from the nucleus.


title: Neutron

text: About the time Rutherford suggested the neutral proton-electron composite, several other publications appeared making similar suggestions, and in 1921 the American chemist W.D. Harkins first named the hypothetical particle a "neutron". The name derives from the Latin root for "neutralis" (neuter) and the Greek suffix "-on" (a suffix used in the names of subatomic particles, i.e. "electron" and "proton"). References to the word "neutron" in connection with the atom can be found in the literature as early as 1899, however.


title: Neutron

text: Throughout the 1920s, physicists assumed that the atomic nucleus was composed of protons and "nuclear electrons" but there were obvious problems. It was difficult to reconcile the proton–electron model for nuclei with the Heisenberg uncertainty relation of quantum mechanics. The Klein paradox, discovered by Oskar Klein in 1928, presented further quantum mechanical objections to the notion of an electron confined within a nucleus. Observed properties of atoms and molecules were inconsistent with the nuclear spin expected from the proton–electron hypothesis. Both protons and electrons carry an intrinsic spin of "ħ". Isotopes of the same species (i.e. having the same number of protons) can have both integer or fractional spin, i.e. the neutron spin must be also fractional ("ħ"). But there is no way to arrange the spins of an electron and a proton (supposed to bond to form a neutron) to get the fractional spin of a neutron.


title: Neutron

text: In 1931, Walther Bothe and Herbert Becker found that if alpha particle radiation from polonium fell on beryllium, boron, or lithium, an unusually penetrating radiation was produced. The radiation was not influenced by an electric field, so Bothe and Becker assumed it was gamma radiation. The following year Irène Joliot-Curie and Frédéric Joliot-Curie in Paris showed that if this "gamma" radiation fell on paraffin, or any other hydrogen-containing compound, it ejected protons of very high energy. Neither Rutherford nor James Chadwick at the Cavendish Laboratory in Cambridge were convinced by the gamma ray interpretation. Chadwick quickly performed a series of experiments that showed that the new radiation consisted of uncharged particles with about the same mass as the proton. These particles were neutrons. Chadwick won the 1935 Nobel Prize in Physics for this discovery.


title: Neutron

text: Models for an atomic nucleus consisting of protons and neutrons were quickly developed by Werner Heisenberg and others. The proton–neutron model explained the puzzle of nuclear spins. The origins of beta radiation were explained by Enrico Fermi in 1934 by the process of beta decay, in which the neutron decays to a proton by "creating" an electron and a (at the time undiscovered) neutrino. In 1935, Chadwick and his doctoral student Maurice Goldhaber reported the first accurate measurement of the mass of the neutron.


title: Neutron

text: By 1934, Fermi had bombarded heavier elements with neutrons to induce radioactivity in elements of high atomic number. In 1938, Fermi received the Nobel Prize in Physics "for his demonstrations of the existence of new radioactive elements produced by neutron irradiation, and for his related discovery of nuclear reactions brought about by slow neutrons". In 1938 Otto Hahn, Lise Meitner, and Fritz Strassmann discovered nuclear fission, or the fractionation of uranium nuclei into light elements, induced by neutron bombardment. In 1945 Hahn received the 1944 Nobel Prize in Chemistry "for his discovery of the fission of heavy atomic nuclei". The discovery of nuclear fission would lead to the development of nuclear power and the atomic bomb by the end of World War II.


title: Neutron

text: Since interacting protons have a mutual electromagnetic repulsion that is stronger than their attractive nuclear interaction, neutrons are a necessary constituent of any atomic nucleus that contains more than one proton (see diproton and neutron–proton ratio). Neutrons bind with protons and one another in the nucleus via the nuclear force, effectively moderating the repulsive forces between the protons and stabilizing the nucleus.


title: Neutron

text: The neutrons and protons bound in a nucleus form a quantum mechanical system wherein each nucleon is bound in a particular, hierarchical quantum state. Protons can decay to neutrons, or vice versa, within the nucleus. This process, called beta decay, requires the emission of an electron or positron and an associated neutrino. These emitted particles carry away the energy excess as a nucleon falls from one quantum state to a lower energy state, while the proton (or neutron) changes to a neutron (or proton). Such decay processes can occur only if allowed by basic energy conservation and quantum mechanical constraints. The stability of nuclei depends on these constraints.


title: Neutron

text: Outside the nucleus, free neutrons are unstable and have a mean lifetime of (about 14 minutes, 40 seconds); therefore the half-life for this process (which differs from the mean lifetime by a factor of ) is (about 10 minutes, 10 seconds). This decay is only possible because the mass of the proton is less than that of the neutron. By the mass-energy equivalence, when a neutron decays to a proton this way it attains a lower energy state. Beta decay of the neutron, described above, can be denoted by the radioactive decay:


title: Neutron

text: For the free neutron the decay energy for this process (based on the masses of the neutron, proton, and electron) is . The maximal energy of the beta decay electron (in the process wherein the neutrino receives a vanishingly small amount of kinetic energy) has been measured at . The latter number is not well-enough measured to determine the comparatively tiny rest mass of the neutrino (which must in theory be subtracted from the maximal electron kinetic energy) as well as neutrino mass is constrained by many other methods.


title: Neutron

text: A small fraction (about one in 1000) of free neutrons decay with the same products, but add an extra particle in the form of an emitted gamma ray:


title: Neutron

text: This gamma ray may be thought of as an "internal bremsstrahlung" that arises from the electromagnetic interaction of the emitted beta particle with the proton. Internal bremsstrahlung gamma ray production is also a minor feature of beta decays of bound neutrons (as discussed below).


title: Neutron

text: A very small minority of neutron decays (about four per million) are so-called "two-body (neutron) decays", in which a proton, electron and antineutrino are produced as usual, but the electron fails to gain the necessary energy to escape the proton (the ionization energy of hydrogen), and therefore simply remains bound to it, as a neutral hydrogen atom (one of the "two bodies"). In this type of free neutron decay, almost all of the neutron decay energy is carried off by the antineutrino (the other "body"). (The hydrogen atom recoils with a speed of only about (decay energy)/(hydrogen rest energy) times the speed of light, or .)


title: Neutron

text: The transformation of a free proton to a neutron (plus a positron and a neutrino) is energetically impossible, since a free neutron has a greater mass than a free proton. But a high-energy collision of a proton and an electron or neutrino can result in a neutron.


title: Neutron

text: While a free neutron has a half life of about , most neutrons within nuclei are stable. According to the nuclear shell model, the protons and neutrons of a nuclide are a quantum mechanical system organized into discrete energy levels with unique quantum numbers. For a neutron to decay, the resulting proton requires an available state at lower energy than the initial neutron state. In stable nuclei the possible lower energy states are all filled, meaning they are each occupied by two protons with spin up and spin down. The Pauli exclusion principle therefore disallows the decay of a neutron to a proton within stable nuclei. The situation is similar to electrons of an atom, where electrons have distinct atomic orbitals and are prevented from decaying to lower energy states, with the emission of a photon, by the exclusion principle.


title: Neutron

text: Neutrons in unstable nuclei can decay by beta decay as described above. In this case, an energetically allowed quantum state is available for the proton resulting from the decay. One example of this decay is carbon-14 (6 protons, 8 neutrons) that decays to nitrogen-14 (7 protons, 7 neutrons) with a half-life of about .


title: Neutron

text: Inside a nucleus, a proton can transform into a neutron via inverse beta decay, if an energetically allowed quantum state is available for the neutron. This transformation occurs by emission of a positron and an electron neutrino:


title: Neutron

text: The transformation of a proton to a neutron inside of a nucleus is also possible through electron capture:


title: Neutron

text: Positron capture by neutrons in nuclei that contain an excess of neutrons is also possible, but is hindered because positrons are repelled by the positive nucleus, and quickly annihilate when they encounter electrons.


title: Neutron

text: Three types of beta decay in competition are illustrated by the single isotope copper-64 (29 protons, 35 neutrons), which has a half-life of about 12.7 hours. This isotope has one unpaired proton and one unpaired neutron, so either the proton or the neutron can decay. This particular nuclide is almost equally likely to undergo proton decay (by positron emission, 18% or by electron capture, 43%) or neutron decay (by electron emission, 39%).


title: Neutron

text: Within the theoretical framework of Standard Model for particle physics, the neutron is composed of two down quarks and an up quark. The only possible decay mode for the neutron that conserves baryon number is for one of the neutron's quarks to change flavour via the weak interaction. The decay of one of the neutron's down quarks into a lighter up quark can be achieved by the emission of a W boson. By this process, the Standard Model description of beta decay, the neutron decays into a proton (which contains one down and two up quarks), an electron, and an electron antineutrino.


title: Neutron

text: The decay of the proton to a neutron occurs similarly through the electroweak force. The decay of one of the proton's up quarks into a down quark can be achieved by the emission of a W boson. The proton decays into a neutron, a positron, and an electron neutrino. This reaction can only occur within an atomic nucleus which has a quantum state at lower energy available for the created neutron.


title: Neutron

text: The mass of a neutron cannot be directly determined by mass spectrometry since it has no electric charge. But since the masses of a proton and of a deuteron can be measured with a mass spectrometer, the mass of a neutron can be deduced by subtracting proton mass from deuteron mass, with the difference being the mass of the neutron plus the binding energy of deuterium (expressed as a positive emitted energy). The latter can be directly measured by measuring the energy (formula_1) of the single gamma photon emitted when a deuteron is formed by a proton capturing a neutron (this is exothermic and happens with zero-energy neutrons). The small recoil kinetic energy (formula_2) of the deuteron (about 0.06% of the total energy) must also be accounted for.


title: Neutron

text: The energy of the gamma ray can be measured to high precision by X-ray diffraction techniques, as was first done by Bell and Elliot in 1948. The best modern (1986) values for neutron mass by this technique are provided by Greene, et al. These give a neutron mass of:


title: Neutron

text: The value for the neutron mass in MeV is less accurately known, due to less accuracy in the known conversion of Da to MeV/"c":


title: Neutron

text: Another method to determine the mass of a neutron starts from the beta decay of the neutron, when the momenta of the resulting proton and electron are measured.


title: Neutron

text: The total electric charge of the neutron is . This zero value has been tested experimentally, and the present experimental limit for the charge of the neutron is , or . This value is consistent with zero, given the experimental uncertainties (indicated in parentheses). By comparison, the charge of the proton is .


title: Neutron

text: Even though the neutron is a neutral particle, the magnetic moment of a neutron is not zero. The neutron is not affected by electric fields, but it is affected by magnetic fields. The magnetic moment of the neutron is an indication of its quark substructure and internal charge distribution.


title: Neutron

text: The value for the neutron's magnetic moment was first directly measured by Luis Alvarez and Felix Bloch at Berkeley, California, in 1940. Alvarez and Bloch determined the magnetic moment of the neutron to be , where "μ" is the nuclear magneton.


title: Neutron

text: In the quark model for hadrons, the neutron is composed of one up quark (charge +2/3 "e") and two down quarks (charge −1/3 "e"). The magnetic moment of the neutron can be modeled as a sum of the magnetic moments of the constituent quarks. The calculation assumes that the quarks behave like pointlike Dirac particles, each having their own magnetic moment. Simplistically, the magnetic moment of the neutron can be viewed as resulting from the vector sum of the three quark magnetic moments, plus the orbital magnetic moments caused by the movement of the three charged quarks within the neutron.


title: Neutron

text: In one of the early successes of the Standard Model in 1964 Mirza A.B. Beg, Benjamin W. Lee, and Abraham Pais theoretically calculated the ratio of proton to neutron magnetic moments to be −3/2, which agrees with the experimental value to within 3%. The measured value for this ratio is . A contradiction of the quantum mechanical basis of this calculation with the Pauli exclusion principle, led to the discovery of the color charge for quarks by Oscar W. Greenberg in 1964.


title: Neutron

text: The above treatment compares neutrons with protons, allowing the complex behavior of quarks to be subtracted out between models, and merely exploring what the effects would be of differing quark charges (or quark type). Such calculations are enough to show that the interior of neutrons is very much like that of protons, save for the difference in quark composition with a down quark in the neutron replacing an up quark in the proton.


title: Neutron

text: The neutron magnetic moment can be roughly computed by assuming a simple nonrelativistic, quantum mechanical wavefunction for baryons composed of three quarks. A straightforward calculation gives fairly accurate estimates for the magnetic moments of neutrons, protons, and other baryons. For a neutron, the result of this calculation is that the magnetic moment of the neutron is given by , where "μ" and "μ" are the magnetic moments for the down and up quarks, respectively. This result combines the intrinsic magnetic moments of the quarks with their orbital magnetic moments, and assumes the three quarks are in a particular, dominant quantum state.


title: Neutron

text: The results of this calculation are encouraging, but the masses of the up or down quarks were assumed to be 1/3 the mass of a nucleon. The masses of the quarks are actually only about 1% that of a nucleon. The discrepancy stems from the complexity of the Standard Model for nucleons, where most of their mass originates in the gluon fields, virtual particles, and their associated energy that are essential aspects of the strong force. Furthermore, the complex system of quarks and gluons that constitute a neutron requires a relativistic treatment. But the nucleon magnetic moment has been successfully computed numerically from first principles, including all of the effects mentioned and using more realistic values for the quark masses. The calculation gave results that were in fair agreement with measurement, but it required significant computing resources.


title: Neutron

text: The neutron is a spin  particle, that is, it is a fermion with intrinsic angular momentum equal to  , where is the reduced Planck constant. For many years after the discovery of the neutron, its exact spin was ambiguous. Although it was assumed to be a spin  Dirac particle, the possibility that the neutron was a spin  particle lingered. The interactions of the neutron's magnetic moment with an external magnetic field were exploited to finally determine the spin of the neutron. In 1949, Hughes and Burgy measured neutrons reflected from a ferromagnetic mirror and found that the angular distribution of the reflections was consistent with spin . In 1954, Sherwood, Stephenson, and Bernstein employed neutrons in a Stern–Gerlach experiment that used a magnetic field to separate the neutron spin states. They recorded two such spin states, consistent with a spin  particle.


title: Neutron

text: As a fermion, the neutron is subject to the Pauli exclusion principle; two neutrons cannot have the same quantum numbers. This is the source of the degeneracy pressure which makes neutron stars possible.


title: Neutron

text: An article published in 2007 featuring a model-independent analysis concluded that the neutron has a negatively charged exterior, a positively charged middle, and a negative core. In a simplified classical view, the negative "skin" of the neutron assists it to be attracted to the protons with which it interacts in the nucleus; but the main attraction between neutrons and protons is via the nuclear force, which does not involve electric charge.


title: Neutron

text: The simplified classical view of the neutron's charge distribution also "explains" the fact that the neutron magnetic dipole points in the opposite direction from its spin angular momentum vector (as compared to the proton). This gives the neutron, in effect, a magnetic moment which resembles a negatively charged particle. This can be reconciled classically with a neutral neutron composed of a charge distribution in which the negative sub-parts of the neutron have a larger average radius of distribution, and therefore contribute more to the particle's magnetic dipole moment, than do the positive parts that are, on average, nearer the core.


title: Neutron

text: The Standard Model of particle physics predicts a tiny separation of positive and negative charge within the neutron leading to a permanent electric dipole moment. But the predicted value is well below the current sensitivity of experiments. From several unsolved puzzles in particle physics, it is clear that the Standard Model is not the final and full description of all particles and their interactions. New theories going beyond the Standard Model generally lead to much larger predictions for the electric dipole moment of the neutron. Currently, there are at least four experiments trying to measure for the first time a finite neutron electric dipole moment, including:


title: Neutron

text: The antineutron is the antiparticle of the neutron. It was discovered by Bruce Cork in 1956, a year after the antiproton was discovered. CPT-symmetry puts strong constraints on the relative properties of particles and antiparticles, so studying antineutrons provides stringent tests on CPT-symmetry. The fractional difference in the masses of the neutron and antineutron is . Since the difference is only about two standard deviations away from zero, this does not give any convincing evidence of CPT-violation.


title: Neutron

text: The existence of stable clusters of 4 neutrons, or tetraneutrons, has been hypothesised by a team led by Francisco-Miguel Marqués at the CNRS Laboratory for Nuclear Physics based on observations of the disintegration of beryllium-14 nuclei. This is particularly interesting because current theory suggests that these clusters should not be stable.


title: Neutron

text: In February 2016, Japanese physicist Susumu Shimoura of the University of Tokyo and co-workers reported they had observed the purported tetraneutrons for the first time experimentally. Nuclear physicists around the world say this discovery, if confirmed, would be a milestone in the field of nuclear physics and certainly would deepen our understanding of the nuclear forces.


title: Neutron

text: The dineutron is another hypothetical particle. In 2012, Artemis Spyrou from Michigan State University and coworkers reported that they observed, for the first time, the dineutron emission in the decay of Be. The dineutron character is evidenced by a small emission angle between the two neutrons. The authors measured the two-neutron separation energy to be 1.35(10) MeV, in good agreement with shell model calculations, using standard interactions for this mass region.


title: Neutron

text: At extremely high pressures and temperatures, nucleons and electrons are believed to collapse into bulk neutronic matter, called neutronium. This is presumed to happen in neutron stars.


title: Neutron

text: The extreme pressure inside a neutron star may deform the neutrons into a cubic symmetry, allowing tighter packing of neutrons.


title: Neutron

text: The common means of detecting a charged particle by looking for a track of ionization (such as in a cloud chamber) does not work for neutrons directly. Neutrons that elastically scatter off atoms can create an ionization track that is detectable, but the experiments are not as simple to carry out; other means for detecting neutrons, consisting of allowing them to interact with atomic nuclei, are more commonly used. The commonly used methods to detect neutrons can therefore be categorized according to the nuclear processes relied upon, mainly neutron capture or elastic scattering.


title: Neutron

text: A common method for detecting neutrons involves converting the energy released from neutron capture reactions into electrical signals. Certain nuclides have a high neutron capture cross section, which is the probability of absorbing a neutron. Upon neutron capture, the compound nucleus emits more easily detectable radiation, for example an alpha particle, which is then detected. The nuclides , , , , , , and are useful for this purpose.


title: Neutron

text: Neutrons can elastically scatter off nuclei, causing the struck nucleus to recoil. Kinematically, a neutron can transfer more energy to a light nucleus such as hydrogen or helium than to a heavier nucleus. Detectors relying on elastic scattering are called fast neutron detectors. Recoiling nuclei can ionize and excite further atoms through collisions. Charge and/or scintillation light produced in this way can be collected to produce a detected signal. A major challenge in fast neutron detection is discerning such signals from erroneous signals produced by gamma radiation in the same detector. Methods such as pulse shape discrimination can be used in distinguishing neutron signals from gamma-ray signals, although certain inorganic scintillator-based detectors have been developed to selectively detect neutrons in mixed radiation fields inherently without any additional techniques.


title: Neutron

text: Fast neutron detectors have the advantage of not requiring a moderator, and are therefore capable of measuring the neutron's energy, time of arrival, and in certain cases direction of incidence.


title: Neutron

text: Free neutrons are unstable, although they have the longest half-life of any unstable subatomic particle by several orders of magnitude. Their half-life is still only about 10 minutes, so they can be obtained only from sources that produce them continuously.


title: Neutron

text: Natural neutron background. A small natural background flux of free neutrons exists everywhere on Earth. In the atmosphere and deep into the ocean, the "neutron background" is caused by muons produced by cosmic ray interaction with the atmosphere. These high-energy muons are capable of penetration to considerable depths in water and soil. There, in striking atomic nuclei, among other reactions they induce spallation reactions in which a neutron is liberated from the nucleus. Within the Earth's crust a second source is neutrons produced primarily by spontaneous fission of uranium and thorium present in crustal minerals. The neutron background is not strong enough to be a biological hazard, but it is of importance to very high resolution particle detectors that are looking for very rare events, such as (hypothesized) interactions that might be caused by particles of dark matter. Recent research has shown that even thunderstorms can produce neutrons with energies of up to several tens of MeV. Recent research has shown that the fluence of these neutrons lies between 10 and 10 per ms and per m depending on the detection altitude. The energy of most of these neutrons, even with initial energies of 20 MeV, decreases down to the keV range within 1 ms.


title: Neutron

text: Even stronger neutron background radiation is produced at the surface of Mars, where the atmosphere is thick enough to generate neutrons from cosmic ray muon production and neutron-spallation, but not thick enough to provide significant protection from the neutrons produced. These neutrons not only produce a Martian surface neutron radiation hazard from direct downward-going neutron radiation but may also produce a significant hazard from reflection of neutrons from the Martian surface, which will produce reflected neutron radiation penetrating upward into a Martian craft or habitat from the floor.


title: Neutron

text: Sources of neutrons for research. These include certain types of radioactive decay (spontaneous fission and neutron emission), and from certain nuclear reactions. Convenient nuclear reactions include tabletop reactions such as natural alpha and gamma bombardment of certain nuclides, often beryllium or deuterium, and induced nuclear fission, such as occurs in nuclear reactors. In addition, high-energy nuclear reactions (such as occur in cosmic radiation showers or accelerator collisions) also produce neutrons from disintegration of target nuclei. Small (tabletop) particle accelerators optimized to produce free neutrons in this way, are called neutron generators.


title: Neutron

text: In practice, the most commonly used small laboratory sources of neutrons use radioactive decay to power neutron production. One noted neutron-producing radioisotope, californium-252 decays (half-life 2.65 years) by spontaneous fission 3% of the time with production of 3.7 neutrons per fission, and is used alone as a neutron source from this process. Nuclear reaction sources (that involve two materials) powered by radioisotopes use an alpha decay source plus a beryllium target, or else a source of high-energy gamma radiation from a source that undergoes beta decay followed by gamma decay, which produces photoneutrons on interaction of the high-energy gamma ray with ordinary stable beryllium, or else with the deuterium in heavy water. A popular source of the latter type is radioactive antimony-124 plus beryllium, a system with a half-life of 60.9 days, which can be constructed from natural antimony (which is 42.8% stable antimony-123) by activating it with neutrons in a nuclear reactor, then transported to where the neutron source is needed.


title: Neutron

text: Nuclear fission reactors naturally produce free neutrons; their role is to sustain the energy-producing chain reaction. The intense neutron radiation can also be used to produce various radioisotopes through the process of neutron activation, which is a type of neutron capture.


title: Neutron

text: Experimental nuclear fusion reactors produce free neutrons as a waste product. But it is these neutrons that possess most of the energy, and converting that energy to a useful form has proved a difficult engineering challenge. Fusion reactors that generate neutrons are likely to create radioactive waste, but the waste is composed of neutron-activated lighter isotopes, which have relatively short (50–100 years) decay periods as compared to typical half-lives of 10,000 years for fission waste, which is long due primarily to the long half-life of alpha-emitting transuranic actinides. Some nuclear fusion-fission hybrids are proposed to make use of those neutrons to either maintain a subcritical reactor or to aid in nuclear transmutation of harmful long lived nuclear waste to shorter lived or stable nuclides.


title: Neutron

text: Free neutron beams are obtained from neutron sources by neutron transport. For access to intense neutron sources, researchers must go to a specialized neutron facility that operates a research reactor or a spallation source.


title: Neutron

text: The neutron's lack of total electric charge makes it difficult to steer or accelerate them. Charged particles can be accelerated, decelerated, or deflected by electric or magnetic fields. These methods have little effect on neutrons. But some effects may be attained by use of inhomogeneous magnetic fields because of the neutron's magnetic moment. Neutrons can be controlled by methods that include moderation, reflection, and velocity selection. Thermal neutrons can be polarized by transmission through magnetic materials in a method analogous to the Faraday effect for photons. Cold neutrons of wavelengths of 6–7 angstroms can be produced in beams of a high degree of polarization, by use of magnetic mirrors and magnetized interference filters.


title: Neutron

text: The neutron plays an important role in many nuclear reactions. For example, neutron capture often results in neutron activation, inducing radioactivity. In particular, knowledge of neutrons and their behavior has been important in the development of nuclear reactors and nuclear weapons. The fissioning of elements like uranium-235 and plutonium-239 is caused by their absorption of neutrons.


title: Neutron

text: "Cold", "thermal", and "hot" neutron radiation is commonly employed in neutron scattering facilities, where the radiation is used in a similar way one uses X-rays for the analysis of condensed matter. Neutrons are complementary to the latter in terms of atomic contrasts by different scattering cross sections; sensitivity to magnetism; energy range for inelastic neutron spectroscopy; and deep penetration into matter.


title: Neutron

text: The development of "neutron lenses" based on total internal reflection within hollow glass capillary tubes or by reflection from dimpled aluminum plates has driven ongoing research into neutron microscopy and neutron/gamma ray tomography.


title: Neutron

text: A major use of neutrons is to excite delayed and prompt gamma rays from elements in materials. This forms the basis of neutron activation analysis (NAA) and prompt gamma neutron activation analysis (PGNAA). NAA is most often used to analyze small samples of materials in a nuclear reactor whilst PGNAA is most often used to analyze subterranean rocks around bore holes and industrial bulk materials on conveyor belts.


title: Neutron

text: Another use of neutron emitters is the detection of light nuclei, in particular the hydrogen found in water molecules. When a fast neutron collides with a light nucleus, it loses a large fraction of its energy. By measuring the rate at which slow neutrons return to the probe after reflecting off of hydrogen nuclei, a neutron probe may determine the water content in soil.


title: Neutron

text: Because neutron radiation is both penetrating and ionizing, it can be exploited for medical treatments. However, neutron radiation can have the unfortunate side-effect of leaving the affected area radioactive. Neutron tomography is therefore not a viable medical application.


title: Neutron

text: Fast neutron therapy uses high-energy neutrons typically greater than 20 MeV to treat cancer. Radiation therapy of cancers is based upon the biological response of cells to ionizing radiation. If radiation is delivered in small sessions to damage cancerous areas, normal tissue will have time to repair itself, while tumor cells often cannot. Neutron radiation can deliver energy to a cancerous region at a rate an order of magnitude larger than gamma radiation.


title: Neutron

text: Beams of low-energy neutrons are used in boron neutron capture therapy to treat cancer. In boron neutron capture therapy, the patient is given a drug that contains boron and that preferentially accumulates in the tumor to be targeted. The tumor is then bombarded with very low-energy neutrons (although often higher than thermal energy) which are captured by the boron-10 isotope in the boron, which produces an excited state of boron-11 that then decays to produce lithium-7 and an alpha particle that have sufficient energy to kill the malignant cell, but insufficient range to damage nearby cells. For such a therapy to be applied to the treatment of cancer, a neutron source having an intensity of the order of a thousand million (10) neutrons per second per cm is preferred. Such fluxes require a research nuclear reactor.


title: Neutron

text: Exposure to free neutrons can be hazardous, since the interaction of neutrons with molecules in the body can cause disruption to molecules and atoms, and can also cause reactions that give rise to other forms of radiation (such as protons). The normal precautions of radiation protection apply: Avoid exposure, stay as far from the source as possible, and keep exposure time to a minimum. But particular thought must be given to how to protect from neutron exposure. For other types of radiation, e.g., alpha particles, beta particles, or gamma rays, material of a high atomic number and with high density makes for good shielding; frequently, lead is used. However, this approach will not work with neutrons, since the absorption of neutrons does not increase straightforwardly with atomic number, as it does with alpha, beta, and gamma radiation. Instead one needs to look at the particular interactions neutrons have with matter (see the section on detection above). For example, hydrogen-rich materials are often used to shield against neutrons, since ordinary hydrogen both scatters and slows neutrons. This often means that simple concrete blocks or even paraffin-loaded plastic blocks afford better protection from neutrons than do far more dense materials. After slowing, neutrons may then be absorbed with an isotope that has high affinity for slow neutrons without causing secondary capture radiation, such as lithium-6.


title: Neutron

text: Hydrogen-rich ordinary water affects neutron absorption in nuclear fission reactors: Usually, neutrons are so strongly absorbed by normal water that fuel enrichment with fissionable isotope is required. The deuterium in heavy water has a very much lower absorption affinity for neutrons than does protium (normal light hydrogen). Deuterium is, therefore, used in CANDU-type reactors, in order to slow (moderate) neutron velocity, to increase the probability of nuclear fission compared to neutron capture.


title: Neutron

text: "Thermal neutrons" are free neutrons whose energies have a Maxwell–Boltzmann distribution with kT =  () at room temperature. This gives characteristic (not average, or median) speed of 2.2 km/s. The name 'thermal' comes from their energy being that of the room temperature gas or material they are permeating. (see "kinetic theory" for energies and speeds of molecules). After a number of collisions (often in the range of 10–20) with nuclei, neutrons arrive at this energy level, provided that they are not absorbed.


title: Neutron

text: In many substances, thermal neutron reactions show a much larger effective cross-section than reactions involving faster neutrons, and thermal neutrons can therefore be absorbed more readily (i.e., with higher probability) by any atomic nuclei that they collide with, creating a heavier – and often unstable – isotope of the chemical element as a result.


title: Neutron

text: Most fission reactors use a neutron moderator to slow down, or "thermalize" the neutrons that are emitted by nuclear fission so that they are more easily captured, causing further fission. Others, called fast breeder reactors, use fission energy neutrons directly.


title: Neutron

text: "Cold neutrons" are thermal neutrons that have been equilibrated in a very cold substance such as liquid deuterium. Such a "cold source" is placed in the moderator of a research reactor or spallation source. Cold neutrons are particularly valuable for neutron scattering experiments.


title: Neutron

text: The use of cold and very cold neutrons (VCN) have been a bit limited compared to the use of thermal neutrons due to the relatively lower flux and lack in optical components. However, Innovative solutions have been proposed to offer more options to the scientific community to promote the use of VCN.


title: Neutron

text: Ultracold neutrons are produced by inelastic scattering of cold neutrons in substances with a low neutron absorption cross section at a temperature of a few kelvins, such as solid deuterium or superfluid helium. An alternative production method is the mechanical deceleration of cold neutrons exploiting the Doppler shift.


title: Neutron

text: A "fast neutron" is a free neutron with a kinetic energy level close to (), hence a speed of ~ (~5% of the speed of light). They are named "fission energy" or "fast" neutrons to distinguish them from lower-energy thermal neutrons, and high-energy neutrons produced in cosmic showers or accelerators. Fast neutrons are produced by nuclear processes such as nuclear fission. Neutrons produced in fission, as noted above, have a Maxwell–Boltzmann distribution of kinetic energies from 0 to ~14 MeV, a mean energy of 2 MeV (for U fission neutrons), and a mode of only 0.75 MeV, which means that more than half of them do not qualify as fast (and thus have almost no chance of initiating fission in fertile materials, such as U and Th).


title: Neutron

text: Fast neutrons can be made into thermal neutrons via a process called moderation. This is done with a neutron moderator. In reactors, typically heavy water, light water, or graphite are used to moderate neutrons.


title: Neutron

text: D–T (deuterium–tritium) fusion is the fusion reaction that produces the most energetic neutrons, with 14.1 MeV of kinetic energy and traveling at 17% of the speed of light. D–T fusion is also the easiest fusion reaction to ignite, reaching near-peak rates even when the deuterium and tritium nuclei have only a thousandth as much kinetic energy as the 14.1 MeV that will be produced.


title: Neutron

text: 14.1 MeV neutrons have about 10 times as much energy as fission neutrons, and are very effective at fissioning even non-fissile heavy nuclei, and these high-energy fissions produce more neutrons on average than fissions by lower-energy neutrons. This makes D–T fusion neutron sources such as proposed tokamak power reactors useful for transmutation of transuranic waste. 14.1 MeV neutrons can also produce neutrons by knocking them loose from nuclei.


title: Neutron

text: On the other hand, these very high-energy neutrons are less likely to simply be captured without causing fission or spallation. For these reasons, nuclear weapon design extensively uses D–T fusion 14.1 MeV neutrons to cause more fission. Fusion neutrons are able to cause fission in ordinarily non-fissile materials, such as depleted uranium (uranium-238), and these materials have been used in the jackets of thermonuclear weapons. Fusion neutrons also can cause fission in substances that are unsuitable or difficult to make into primary fission bombs, such as reactor grade plutonium. This physical fact thus causes ordinary non-weapons grade materials to become of concern in certain nuclear proliferation discussions and treaties.


title: Neutron

text: Other fusion reactions produce much less energetic neutrons. D–D fusion produces a 2.45 MeV neutron and helium-3 half of the time, and produces tritium and a proton but no neutron the rest of the time. D–He fusion produces no neutron.


title: Neutron

text: A fission energy neutron that has slowed down but not yet reached thermal energies is called an epithermal neutron.


title: Neutron

text: Cross sections for both capture and fission reactions often have multiple resonance peaks at specific energies in the epithermal energy range. These are of less significance in a fast-neutron reactor, where most neutrons are absorbed before slowing down to this range, or in a well-moderated thermal reactor, where epithermal neutrons interact mostly with moderator nuclei, not with either fissile or fertile actinide nuclides. But in a partially moderated reactor with more interactions of epithermal neutrons with heavy metal nuclei, there are greater possibilities for transient changes in reactivity that might make reactor control more difficult.


title: Neutron

text: Ratios of capture reactions to fission reactions are also worse (more captures without fission) in most nuclear fuels such as plutonium-239, making epithermal-spectrum reactors using these fuels less desirable, as captures not only waste the one neutron captured but also usually result in a nuclide that is not fissile with thermal or epithermal neutrons, though still fissionable with fast neutrons. The exception is uranium-233 of the thorium cycle, which has good capture-fission ratios at all neutron energies.


title: Neutron

text: High-energy neutrons have much more energy than fission energy neutrons and are generated as secondary particles by particle accelerators or in the atmosphere from cosmic rays. These high-energy neutrons are extremely efficient at ionization and far more likely to cause cell death than X-rays or protons.


title: Harlan Ellison

text: Harlan Jay Ellison (May 27, 1934 – June 28, 2018) was an American writer, known for his prolific and influential work in New Wave speculative fiction and for his outspoken, combative personality. Robert Bloch, the author of "Psycho", described Ellison as "the only living organism I know whose natural habitat is hot water."


title: Harlan Ellison

text: His published works include more than 1,700 short stories, novellas, screenplays, comic book scripts, teleplays, essays, and a wide range of criticism covering literature, film, television, and print media. Some of his best-known works include the 1967 "" episode "The City on the Edge of Forever" (he subsequently wrote a book about the experience that includes his original screenplay), his "A Boy and His Dog" cycle, and his short stories "I Have No Mouth, and I Must Scream" and "'Repent, Harlequin!' Said the Ticktockman". He was also editor and anthologist for "Dangerous Visions" (1967) and "Again, Dangerous Visions" (1972). Ellison won numerous awards, including multiple Hugos, Nebulas, and Edgars.


title: Harlan Ellison

text: Ellison was born to a Jewish family in Cleveland, Ohio, on May 27, 1934, the son of Serita (née Rosenthal) and Louis Laverne Ellison, a dentist and jeweler. He had an older sister, Beverly (Rabnick), who was born in 1926. She died in 2010 without having spoken to him since their mother's funeral in 1976. His family subsequently moved to Painesville, Ohio, but returned to Cleveland in 1949, following his father's death. Ellison frequently ran away from home (in an interview with Tom Snyder he would later claim it was due to discrimination by his high school peers), taking an array of odd jobs—including, by age 18, "tuna fisherman off the coast of Galveston, itinerant crop-picker down in New Orleans, hired gun for a wealthy neurotic, nitroglycerine truck driver in North Carolina, short-order cook, cab driver, lithographer, book salesman, floorwalker in a department store, door-to-door brush salesman, and as a youngster, an actor in several productions at the Cleveland Play House". In 1947, a fan letter he wrote to "Real Fact Comics" became his first published writing.


title: Harlan Ellison

text: Ellison attended Ohio State University for 18 months (1951–53) before being expelled. He said the expulsion was for hitting a professor who had denigrated his writing ability, and over the next 20 or so years he sent that professor a copy of every story that he published.


title: Harlan Ellison

text: Ellison published two serialized stories in the "Cleveland News" during 1949, and he sold a story to EC Comics early in the 1950s. During this period, Ellison was an active and visible member of science fiction fandom, and published his own science fiction fanzines, such as "Dimensions" (which had previously been the "Bulletin of the Cleveland Science Fantasy Society" for the Cleveland Science Fantasy Society, and later "Science Fantasy Bulletin".) Ellison moved to New York City in 1955 to pursue a writing career, primarily in science fiction. Over the next two years, he published more than 100 short stories and articles. The short stories collected as "Sex Gang" — which Ellison described in a 2012 interview as "mainstream erotica" — date from this period.


title: Harlan Ellison

text: His first novel, "Web of the City", was published during his military service in 1958, and he said that he had written the bulk of it while undergoing basic training at Fort Benning, Georgia.


title: Harlan Ellison

text: Ellison moved to California in 1962 and began selling his writing to Hollywood. He co-wrote the screenplay for "The Oscar" (1966), starring Stephen Boyd and Elke Sommer. Ellison also sold scripts to many television shows: "The Loretta Young Show" (using the name Harlan Ellis),"The Flying Nun", "Burke's Law", "Route 66," "The Outer Limits", "", "The Man from U.N.C.L.E.", "Cimarron Strip", and "The Alfred Hitchcock Hour".


title: Harlan Ellison

text: Ellison's screenplay for the "Star Trek" episode "The City on the Edge of Forever" has been considered the best of the 79 episodes in the series.


title: Harlan Ellison

text: In 1965, he participated in the second and third Selma to Montgomery marches, led by Martin Luther King Jr.


title: Harlan Ellison

text: In 1966, in an article that "Esquire" magazine later named as the best magazine piece ever written, the journalist Gay Talese wrote a profile of Frank Sinatra. The article, entitled "Frank Sinatra Has a Cold", briefly describes a clash between Sinatra and a young Harlan Ellison, in which the crooner took exception to Ellison's boots during a billiards game.


title: Harlan Ellison

text: Ellison was hired as a writer for Walt Disney Studios, but was fired on his first day after Roy O. Disney overheard him in the studio commissary joking about making a pornographic animated film featuring Disney characters.


title: Harlan Ellison

text: Ellison continued to publish short fiction and nonfiction pieces in various publications, including some of his best known stories. "'Repent, Harlequin!' Said the Ticktockman" (1965) is a celebration of civil disobedience against repressive authority. "I Have No Mouth, and I Must Scream" (1967) is a story where five humans are tormented by an all-knowing computer throughout eternity. The story was the basis of a 1995 computer game; Ellison participated in the game's design and provided the voice of the god-computer AM. Another story, "A Boy and His Dog", examines the nature of friendship and love in a violent, post-apocalyptic world and was made into the 1975 film of the same name, starring Don Johnson.


title: Harlan Ellison

text: In 1967, Ellison edited the "Dangerous Visions" collection, which attracted 'special citation at the 26th World SF Convention for editing "the most significant and controversial SF book published in 1967."' In his introduction Isaac Asimov described it epitomising a 'second revolution' in Science Fiction as 'science receded and modern fictional techniques came to the fore'.


title: Harlan Ellison

text: From 1968 to 1970, Ellison wrote a regular column on television for the "Los Angeles Free Press". Titled "The Glass Teat," Ellison's column examined television's impact on the politics and culture of the time, including its presentations of sex, politics, race, the Vietnam War, and violence. The essays were collected in two anthologies, "The Glass Teat: Essays of Opinion on Television" followed by "The Other Glass Teat".


title: Harlan Ellison

text: Ellison served as creative consultant to the 1980s version of "The Twilight Zone" science fiction TV series and "Babylon 5". As a member of the Screen Actors Guild (SAG), he had voice-over credits for shows, including "The Pirates of Dark Water", "Mother Goose and Grimm", "Space Cases", "Phantom 2040", and "Babylon 5", as well as making an onscreen appearance in the "Babylon 5" episode "The Face of the Enemy".


title: Harlan Ellison

text: A frequent guest on the Los Angeles science fiction / fantasy culture radio show "Hour 25," hosted by Mike Hodel, Ellison took over as host when Hodel died. Ellison's tenure was from May 1986 to June 1987.


title: Harlan Ellison

text: Ellison's short story "The Man Who Rowed Christopher Columbus Ashore" (1992) was selected for inclusion in the 1993 edition of "The Best American Short Stories".


title: Harlan Ellison

text: In 2014, Ellison made a guest appearance on the album "Finding Love in Hell" by the stoner metal band Leaving Babylon, reading his piece "The Silence" (originally published in "Mind Fields") as an introduction to the song "Dead to Me."


title: Harlan Ellison

text: Ellison's official website, harlanellison.com, was launched in 1995 as a fan page; for several years, Ellison was a regular poster in its discussion forum.


title: Harlan Ellison

text: Ellison married five times; each relationship ended within a few years, except the last. His first wife was Charlotte Stein, whom he married in 1956. They divorced in 1960, and he later described the marriage as "four years of hell as sustained as the whine of a generator." Later that year he married Billie Joyce Sanders; they divorced in 1963. His 1966 marriage to Loretta Patrick lasted only seven weeks. In 1976, he married Lori Horowitz. He was 41 and she was 19, and he later said of the marriage, "I was desperately in love with her, but it was a stupid marriage on my part." They were divorced after eight months. He and Susan Toth married in 1986, and they remained together, living in Los Angeles, until his death 32 years later. Susan died in August 2020.


title: Harlan Ellison

text: In 1994, he had a heart attack and was hospitalized for quadruple coronary artery bypass surgery. From 2010, he received treatment for clinical depression.


title: Harlan Ellison

text: In September 2007, Ellison attended the Midwestern debut of the documentary about his life, "Dreams with Sharp Teeth" at the Cleveland Public Library in his hometown of Cleveland, Ohio. This would be Ellison's last public appearance in his hometown.


title: Harlan Ellison

text: On about October 10, 2014, Ellison had a stroke. Although his speech and cognition were unimpaired, he suffered paralysis on his right side, for which he was expected to spend several weeks in physical therapy before being released from the hospital.


title: Harlan Ellison

text: Harlan Ellison died in his sleep, at home in Los Angeles in the morning of June 28, 2018. His literary estate is currently executed by "Babylon 5" creator J. Michael Straczynski.


title: Harlan Ellison

text: Ellison on occasion used the pseudonym Cordwainer Bird to alert members of the public to situations in which he felt his creative contribution to a project had been mangled by others, beyond repair, typically Hollywood producers or studios (see also Alan Smithee). The first such work to which he signed the name was "The Price of Doom", an episode of "Voyage to the Bottom of the Sea" (though it was misspelled as Cord Wainer Bird in the credits). An episode of "Burke's Law" ("Who Killed Alex Debbs?") credited to Ellison contains a "character" given this name, played by Sammy Davis Jr.


title: Harlan Ellison

text: The "Cordwainer Bird" moniker is a tribute to fellow SF writer Paul M. A. Linebarger, better known by his pen name, Cordwainer Smith. The origin of the word "cordwainer" is "shoemaker" (from working with shell cordovan leather for shoes). The term used by Linebarger was meant to imply the industriousness of the pulp author. Ellison said, in interviews and in his writing, that his version of the pseudonym was meant to mean "a shoemaker for birds". Since he used the pseudonym mainly for works he wanted to distance himself from, it may be understood to mean that "this work is for the birds" or that it is of as much use as shoes to a bird. Stephen King once said he thought that it meant that Ellison was giving people who mangled his work a literary version of "the bird" (given credence by Ellison himself in his own essay titled "Somehow, I Don't Think We're in Kansas, Toto", describing his experience with the "Starlost" television series).


title: Harlan Ellison

text: The Bird moniker became a character in one of Ellison's own stories. In his 1978 book "Strange Wine", Ellison explains the origins of the Bird and goes on to state that Philip José Farmer wrote Cordwainer into the Wold Newton family that the latter writer had developed. The thought of such a whimsical object lesson being related to such lights as Doc Savage, The Shadow, Tarzan, and all the other pulp heroes prompted Ellison to play with the concept, resulting in "The New York Review of Bird", in which an annoyed Bird uncovers the darker secrets of the New York literary establishment before beginning a pulpish slaughter of the same.


title: Harlan Ellison

text: Other pseudonyms Ellison used during his career include Jay Charby, Sley Harson, Ellis Hart, John Magnus, Paul Merchant, Pat Roeder, Ivar Jorgenson, Derry Tiger, Harlan Ellis and Jay Solo.


title: Harlan Ellison

text: Ellison had a reputation for being abrasive and argumentative. He generally agreed with this assessment, and a dust jacket from one of his books described him as "possibly the most contentious person on Earth." Ellison filed numerous grievances and attempted lawsuits; as part of a dispute about fulfillment of a contract, he once sent 213 bricks to a publisher postage due, followed by a dead gopher via fourth-class mail. In an October 2017 piece in "Wired", Ellison was dubbed "Sci-Fi's Most Controversial Figure."


title: Harlan Ellison

text: At Stephen King's request, Ellison provided a description of himself and his writing in "Danse Macabre": "My work is foursquare for chaos. I spend my life personally, and my work professionally, keeping the soup boiling. Gadfly is what they call you when you are no longer dangerous; I much prefer troublemaker, malcontent, desperado. I see myself as a combination of Zorro and Jiminy Cricket. My stories go out from here and raise hell. From time to time some denigrater or critic with umbrage will say of my work, 'He only wrote that to shock.' I smile and nod. Precisely."


title: Harlan Ellison

text: Ellison repeatedly criticized how "Star Trek" creator and producer Gene Roddenberry (and others) rewrote his original script for the 1967 episode "The City on the Edge of Forever". Despite his objections, Ellison kept his own name on the shooting script instead of using "Cordwainer Bird" to indicate displeasure (see above).


title: Harlan Ellison

text: Ellison's original script was first published in the 1976 anthology "Six Science Fiction Plays", edited by Roger Elwood. The aired version was adapted for the "Star Trek" Fotonovel series in 1977. In 1995, Borderlands Press published "The City on the Edge of Forever", with nearly 300 pages, comprising an essay by Ellison, four versions of the teleplay, and eight "Afterwords" contributed by other parties. He greatly expanded the introduction for the paperback edition, in which he explained what he called a "fatally inept" treatment.


title: Harlan Ellison

text: Both versions of the script won awards: Ellison's original script won the 1968 Writers Guild Award for best episodic drama in television, while the shooting script won the 1968 Hugo Award for Best Dramatic Presentation.


title: Harlan Ellison

text: On March 13, 2009, Ellison sued CBS Paramount Television, seeking payment of 25% of net receipts from merchandising, publishing, and other income from the episode since 1967; the suit also names the Writers Guild of America for allegedly failing to act on Ellison's behalf. On October 23, 2009, "Variety" magazine reported that a settlement had been reached.


title: Harlan Ellison

text: Ellison was among those who in 1968 signed an anti-Vietnam War advertisement in "Galaxy Science Fiction". In 1969, Ellison was Guest of Honor at Texas A&M University's first science fiction convention, Aggiecon, where he reportedly referred to the university's Corps of Cadets as "America's next generation of Nazis", inspired in part by the continuing Vietnam War. Although the university was no longer solely a military school (from 1965), the student body was predominantly made up of cadet members. Between Ellison's anti-military remarks and a food fight that broke out in the ballroom of the hotel where the gathering was held (although, according to Ellison in 2000, the food fight actually started in a Denny's because the staff disappeared and they could not get their check), the school's administration almost refused to approve the science fiction convention the next year and no guest of honor was invited for the next two Aggiecons. However, Ellison was subsequently invited back as Guest of Honor for Aggiecon V (1974).


title: Harlan Ellison

text: "The Last Dangerous Visions" (TLDV), the third volume of Ellison's anthology series, was originally announced for publication in 1973, but had not been published. Nearly 150 writers, many now dead, submitted works for the volume. In 1993, Ellison threatened to sue the New England Science Fiction Association (NESFA) for publishing "Himself in Anachron", a short story written by Cordwainer Smith and originally sold to Ellison for the anthology by his widow. The NESFA later reached an amicable settlement after it was revealed that the story contract had expired, allowing them to legally acquire it for publication.


title: Harlan Ellison

text: British science fiction author Christopher Priest criticized Ellison's editorial practices in an article entitled "The Book on the Edge of Forever", later expanded into a book. Priest documented a half-dozen unfulfilled promises by Ellison to publish "TLDV" within a year of the statement. Priest claims that he submitted a story at Ellison's request, which Ellison retained for several months until Priest withdrew the story and demanded that Ellison return the manuscript. Ellison was incensed by "The Book on the Edge of Forever" and, personally or by proxy, threatened Priest on numerous occasions after its publication.


title: Harlan Ellison

text: In November 2020, the executor of the Harlan Ellison estate, J. Michael Straczynski, announced on Patreon that he was proceeding with the final preparations for the publication of TLDV with the proceeds to go to the Harlan and Susan Ellison Trust. The book was expected to be published in April 2021, as significant publisher interest was expressed.


title: Harlan Ellison

text: Christopher Priest was unimpressed, saying that Straczynski was "in the same sort of unenviable position as Trump's caddie", but as an experienced professional would possibly work something out. He added "I kind of lost interest in all that years ago. Ellison clearly did too, along with everyone else. (Although I gather he went on with his magical thinking if anyone asked when he was going to deliver). Many of the stories were withdrawn, because Ellison acted like a dick. Of the ones that remain, most of them are by writers who are now deceased, so the rights have expired and the estates would have to be traced. A lot of the writers have disowned their stories as juvenilia, or outdated, or simply because Ellison was acting like a dick."


title: Harlan Ellison

text: Despite early hopes of a 2021 release for TLDV, 2021 came and went with no book. An October 2021 'progress report' from Straczynski revealed that the book was still in preparation. On May 2, 2022, Straczynski announced that the book would be published in 2023.


title: Harlan Ellison

text: Shortly after the release of "Star Wars" (1977), Ben Roberts contacted Ellison to develop a script based on Isaac Asimov's "I, Robot" short story collection for Warner Brothers; Ellison and Asimov had been long-time friends, so Ellison may be presumed to have attached particular significance to the project. In a meeting with the Head of Production at Warners, Robert Shapiro, Ellison concluded that Shapiro was commenting on the script without having read it and accused him of having the "intellectual and cranial capacity of an artichoke". Shortly afterwards, Ellison was dropped from the project. Without Ellison, the film came to a dead end, because subsequent scripts were unsatisfactory to potential directors. After a change in studio heads, Warner allowed Ellison's script to be serialized in "Isaac Asimov's Science Fiction Magazine" and published in book form. The 2004 film "I, Robot", starring Will Smith, has no connection to Ellison's script.


title: Harlan Ellison

text: In 1985, Ellison allegedly publicly assaulted author and critic Charles Platt at the Nebula Awards banquet. Platt did not pursue legal action against Ellison and the two men later signed a "non-aggression pact", promising never to discuss the incident again nor to have any contact with one another. Platt claims that Ellison often publicly boasted about the incident.


title: Harlan Ellison

text: Ellison voiced strong support for Ed Kramer, founder of Dragon*Con, after Kramer was accused of sexual abuse of children in 2000. Ellison and others disputed the evidence against Kramer, and also alleged Kramer was being held in jail in violation of his right to a speedy trial.


title: Harlan Ellison

text: When author Nancy A. Collins spoke up against Kramer, Ellison led a long-standing feud against her before Kramer entered an Alford Plea in 2013.


title: Harlan Ellison

text: Ellison was presented with a special committee award at the 2006 Hugo Awards ceremony. When Ellison got to the podium, presenter Connie Willis asked him "Are you going to be good?" When she asked the question a second time, Ellison put the microphone in his mouth, to the crowd's laughter. He then placed his hand on her breast during an embrace. Ellison subsequently complained that Willis refused to acknowledge his apology.


title: Harlan Ellison

text: On September 20, 2006, Ellison sued comic book and magazine publisher Fantagraphics, stating they had defamed him in their book "Comics As Art (We Told You So)". The book recounts the history of Fantagraphics and discussed a lawsuit that resulted from a 1980 Ellison interview with Fantagraphics' industry news magazine, "The Comics Journal". In this interview Ellison referred to comic book writer Michael Fleisher, calling him "bugfuck" and "derange-o". Fleisher lost his libel suit against Ellison and Fantagraphics on December 9, 1986.


title: Harlan Ellison

text: Ellison, after reading unpublished drafts of the book on Fantagraphics's website, believed that he had been defamed by several anecdotes related to this incident. He sued in the Superior Court for the State of California, in Santa Monica. Fantagraphics attempted to have the lawsuit dismissed. In their motion to dismiss, Fantagraphics argued that the statements were both their personal opinions and generally believed to be true anecdotes. On February 12, 2007, the presiding judge ruled against Fantagraphics' anti-SLAPP motion for dismissal. On June 29, 2007, Ellison claimed that the litigation had been resolved pending Fantagraphics' removal of all references to the case from their website. No money or apologies changed hands in the settlement as posted on August 17, 2007.


title: Harlan Ellison

text: In a 1980 lawsuit against ABC and Paramount Pictures, Ellison and Ben Bova claimed that the TV series "Future Cop" was based on their short story "Brillo", winning a $337,000 judgement.