15093684
Lorentz transform of black-body radiation temperature
The Lorentz transform of black-body radiation has been investigated from the viewpoint of relativistic statistical mechanics. The result shows that the well-known expression with the directional temperature can be derived based on the inverse-temperature four-vector. The directional temperature in the past literature was the result of mathematical manipulation and its physical meaning is not clear. The inverse-temperature four-vector has, in contrast, clear meaning to understand relativistic thermodynamical processes.
15956163
Factor Two Discrepancy of Hawking Radiation Temperature
The possibility of an alternative way to formulate the Hawking radiation in a static Schwarzschild spacetime has been explored. To calculate the Hawking radiation, there can be two possible choices of the spacetime wedge pairs in the Krucal-Szekeres coordinates. One is the wedge pair consists of exterior spacetime of a black hole and the exterior spacetime of a white hole, and the other is that of exterior and interior spacetimes of one black hole. The radiation from the former is the Hawking's original one. Though the the latter has been often regarded as the same phenomena as the former, the result here suggests it is not; its radiation has a temperature twice as high as the Hawking temperature.
8249851
On Hawking/Unruh Process: Where does the Radiation Come from?
The energy source of the radiation in Unruh/Hawking process is investigated with emphasis on the particle number definition based on conservation laws. It has been shown that the particle radiation is not the result of pair creation by the gravitational force, but the result of difference in the conservation laws to define the particle number. The origin of the radiated energy in the distant future corresponds to the zero point oscillations with infinitely large wave numbers. This result implies the need of reconsideration on the scenario of black hole evaporation.
55094258
Three Views of a Secret in Relativistic Thermodynamics
It has been shown three different views in relativistic thermodynamics can be derived from the basic formulation proposed by van Kampen and Israel. The way to decompose energy-momentum into work and heat is not uniquely determined; the different choices result in different views. Also the definition of three dimensional volume causes ambiguity of thermodynamical quantities. The present paper shows various theories are obtained depending on the choice of these two factors. Subject Index: 070
59371083
Slow RI-beams from projectile fragment separators
Abstract The projectile fragment separator provides a wide variety of short-lived RI-ions with less restrictions on their chemical property or lifetime limit. The beam energy and quality is, however, not adequate for low-energy beam experiments, in particular for trapping experiments. Recently, one has proposed to obtain a low-energy beam from an energetic RI-beam leaving a projectile fragment separator by using a large gas-catcher and an rf ion-guide system. In off-line and in on-line test experiments, the principle of the rf ion-guide was proven. An overall efficiency of 0.2% for 70 MeV/u 8Li from the RIKEN projectile fragment separator (RIPS) was obtained so far.
118202138
Sources of Gravitational Waves for TAMA300
121768272
Neutron and photon production from thick targets bombarded by 30-MeV p, 33-MeV d, 65-MeV /sup 3/He, and 65-MeV. cap alpha. ions: Experiment and comparison with cascade Monte Carlo calculations
The energy spectra of neutrons and photons emitted by thick targets of carbon, iron, copper, and lead at angles of 0, 15, 30, 45, 75, and 135 deg to the incident beam of 33-MeV deuteron, 65-MeV /sup 3/He, and 65-MeV alpha ions were obtained by unfolding the pulse height distributions measured with an NE-213 scintillator. The angular distributions of neutrons above 4 MeV and photons above 1.5 MeV were obtained by integrating the measured spectra. The total neutron yield was obtained by estimating the neutron yield below a few MeV by fitting the spectra measured above that energy to the Maxwellian distribution and showed good agreement with other experimental results. The measured spectra were analyzed by the thick-target radiation transport Monte Carlo code based on the intranuclear-cascade-evaporation model. The validity of the model was tested at the lower projectile energy limit through this comparison.
3111498
Possibility of direct measurement of the acceleration of the universe using 0.1 Hz band laser interferometer gravitational wave antenna in space.
It may be possible to construct a laser interferometer gravitational wave antenna in space with h(rms) approximately 10(-27) at f approximately 0.1 Hz in this century. Using this antenna, (1) typically 10(5) chirp signals of coalescing binary neutron stars per year may be detected with S/N approximately 10(4); (2) we can directly measure the acceleration of the universe by a 10 yr observation of binary neutron stars; and (3) the stochastic gravitational waves of Omega(GW) > or similar to 10(-20) predicted by the inflation may be detected by correlation analysis. Our formula for phase shift due to accelerating motion might be applied for binary sources of LISA.