119559515
Alight a beam and beaming light: A theme with variations
The interaction of light (coherent and incoherent) with charged particle beams is explored in various configurations: incoherent scattering of coherent light (laser) from an incoherent particle beam (high temperature), coherent scattering of coherent light (laser) from a “cold” (bunched) beam, femtosecond generation of particle and light beams via “optical slicing” and Thomson/Compton scattering techniques, etc. The domains of ultrashort temporal duration (femtoseconds) as well as ultrashort wavelengths (x rays and shorter), with varying degrees of coherence, are explored. The relevance to a few critical areas of research in the natural sciences, e.g., ultrafast material, chemical and biological processes, protein folding, particle phase space cooling, etc. are touched upon. All the processes discussed involve proper interpretation and understanding of coherent states of matter and radiation, as well as the quality and quantity of information and energy embedded in them.
116926076
Some fundamental aspects of fluctuations and coherence in charged‐particle beams in storage rings
A conceptual survey and exposition is presented of some fundamendal aspects of fluctuations and coherence, as well as the interplay between the two, in coasting charged‐particle beams—both continuous and bunched—in storage rings. A detailed study is given of the spectral properties of the incoherent phase‐space Schottky fluctuations, their propagation as waves in the beam, and the analytic complex coherent beam electromagnetic response or transfer function. The modification or distortion of these by collective interactions is examined in terms of simple regeneration mechanisms. Collective or coherent forces in the beam–storage‐ring system are described by defining suitable impedance functions or propagators, and a brief discussion of the coherent collective modes and their stability is provided, including a general and rigorous description of the Nyquist stability criterion. The nature of the critical fluctuations near an instability threshold is explored. The concept of Landau damping and its connection ...
55975443
Accelerator physics experiments at Aladdin
DISCLAIMER LBL--19905 DE86 005847 -J or un or _ames my 1epI liability or reaponli- bility for the accuracy com~ '. or usefuloeu or uy information, apparatus product, or r- _ _ _ _ or ~ts tbat Its UJe would not • I i · · eoce herein to any SpccUlC COOImercial oil ID nnse !, Ya!ely owned rishts. Refer- manufa<1urer, or othcr1¥ise does not PI' .~ pr~, or se~ by trade name, trademark, riI Y mendation, or favorinS by the United Go constItute or Imply its endorsement, recom- es veroment or an v agen thereof Th . e VIews a nd optDlODS of authors ex-..... b . d r'~ erelD 0 not necessarily late flee UDlted States Goveroment or any agency thereof. S or re t those of tbe or work IpOIIIOred b Gom-nmcnl Neilllcr Ik United St.tcs r _ _ y u aaency or the United States -- mUea any ......... ty exPRU JJDJc:nt DOl' uy .... .-~ thereof. or t heir cm.......-. . plied, DOl' any This n:port . . . prepm:d U .. _at ne;;::- ACCELERATOR PHYSICS EXPERIMENTS AT ALADDIN* S. Chattopadhyay, K. Cornacchia, A. Jackson, and K.S. Zisman Lawrence Berkeley Laboratory University of California Berkeley, California 94720 July 1985 This work vas partiaUy supported by the Direcloc-. Office of Enct'yllcl wlib ft.M IlJ.S. hH
136682515
Hydrogen in materials and vacuum systems : First International wordshop on hydrogen in materials and vacuum systems, Newport News, Virginia 11-13 November 2002
All papers were peer-reviewed. Hydrogen plays a key role in materials, beneficial in some cases, problematic in others. In all such systems a detailed understanding of the hydrogen-based interaction is necessary for control, improvements, and for possible new applications. This hydrogen workshop proceeding incorporates contributions from semi-conducting, normal conducting (metals) and superconducting materials, as well as vacuum communities who deal with the hydrogen-materials issue. The technical areas covered in these proceedings include hydrogen in materials, hydrogen interactions and dynamics in semiconductors, hydrogen adsorption-storage-generation and distribution, hydrogen in niobium, hydrogen in vacuum systems, gaseous hydrogen accelerator structures, and magnetically suspended liquid hydrogen transfer lines.
51748746
Proposal for a one GeV plasma wakefield acceleration experiment at SLAC
Abstract A plasma-based wakefield acceleration experiment E-157 has been approved at SLAC to study acceleration of parts of an SLC bunch by up to 1 GeV/m over a length of 1 m. A single SLC bunch is used to both induce wakefields in the 1 m long plasma and to witness the resulting beam acceleration. The experiment will explore and further develop the techniques that are needed to apply high-gradient plasma wakefield acceleration to large-scale accelerators. The 1 m length of the experiment is about two orders of magnitude larger than for other high gradient plasma wakefield acceleration experiments and the 1 GeV/m accelerating gradient is roughly ten times larger than that achieved with conventional metallic structures. Using existing SLAC facilities, the experiment will study high gradient acceleration at the forefront of advanced accelerator research.
124556579
Motivation and goals of ERL 2005
Various types of ERL sources are introduced, the relevant beam physics and accelerator technology issues noted, innovative areas of development identified and current and future goals of ERL research and development established.
119244873
Reciprocal NUT spacetimes
In this paper, we study the Ehlers' transformation (sometimes called gravitational duality rotation) for reciprocal static metrics. First, we introduce the concept of reciprocal metric. We prove a theorem which shows how we can construct a certain new static solution of Einstein field equations using a seed metric. Later, we investigate the family of stationary spacetimes of such reciprocal metrics. The key here is a theorem from Ehlers', which relates any static vacuum solution to a unique stationary metric. The stationary metric has a magnetic charge. The spacetime represents Newman-Unti-Tamburino (NUT) solutions. Since any stationary spacetime can be decomposed into a 1 + 3 time-space decomposition, Einstein field equations for any stationary spacetime can be written in the form of Maxwell's equations for gravitoelectromagnetic fields. Further, we show that this set of equations is invariant under reciprocal transformations. An additional point is that the NUT charge changes the sign. As an instructive example, by starting from the reciprocal Schwarzschild as a spherically symmetric solution and reciprocal Morgan–Morgan disk model as seed metrics we find their corresponding stationary spacetimes. Starting from any static seed metric, performing the reciprocal transformation and by applying an additional Ehlers' transformation we obtain a family of NUT spaces with negative NUT factor (reciprocal NUT factors).
119202914
Interaction Between Tachyon and Hessence (or Hantom) Dark Energies
In this work, we have considered that the universe is filled with tachyon and hessence (or hantom) dark energies. Subsequently we have investigated the interactions between tachyon and hessence (hantom) dark energies and calculated the potentials considering the power law form of the scale factor. It has been revealed that the tachyonic potential always decreases and hessence (or hantom) potential increases with corresponding fields. Furthermore, we have considered a correspondence between the hessence (or hantom) dark energy density and variable modified Chaplygin gas energy density. From this, we have found the expressions of the arbitrary positive constants B0 and C of variable modified Chaplygin gas.
59054830
A Study on Ricci Dark Energy in Bulk-Brane Interaction
We have investigated the effects of the interaction between a brane universe and the bulk in which it is embedded. Considering the effects of the interaction between a brane universe and the bulk, we have obtained the equation of state for the interacting holographic Ricci dark energy density in the flat universe. We have investigated the impact of on the equation of state . Also, considering the power law for of the scale factor, we have observed that nontrivial contributions of dark energy which differ from the standard matter fields confined to the brane are increasing with the evolution of the universe.
121458769
Various aspects of interacting modified holographic Ricci dark energy
The present paper reports various aspects of modified holographic Ricci dark energy interacting with pressureless dark matter in a flat Friedman-Robertson-Walker universe. The cosmological parameters, namely, Hubble parameter, equation of state parameter and deceleration parameter have been studied under this interaction. Statfinder diagnostics has also been studied, where attainment of $$\Uplambda$$ΛCDM phase of the universe under this interaction has been observed. A study on fractional densities has prominently shown the transition from matter dominated to dark energy dominated universe.
119097172
Propagation of Fluctuations in Au+Au Collisions at FAIR energy
Variable Energy Cyclotron Centre, Kolkata India(Dated: August 25, 2014)Event by event ﬂuctuations of particle multiplicities and their ratios are considered to be sensitiveprobes to the exotic phenomena in high energy heavy ion collisions like phase transtion or theoccurence of critical point. These phenomena might take place at diﬀerent time after the collisionbased on fulﬁlling the required conditions at a particular time. Fluctuations are therefore expectedto show non-monotonic behaviour at the of time of occurence of these phenomena. Experimentally,ﬂuctuations are measured at freezeout. In this work, using the hybrid version of the UrQMD eventgenerator, we have investigated the propagation of ﬂuctuations of particle multiplicities, their ratiosand the ratio of total positive and negative charges in AuAu collisions at E