55024702
COHERENT INSTABILITY AND ION TRAPPING CONSIDERATIONS FOR ALADDIN LATTICES
LBL-19281 UC - i8 CO HERENT INS TABILITY AND ION TRAPPING CONSIDERATIONS FOR ALADDIN LATTICES S . Chattopadhya y May 1985 Prepared for the U.S. Departm ent of Energy under Contract DE-AC03-76SF00098
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
55285360
Optimization of the Parameters of a Storage Ring for a High Power XUV Free Electron Laser
In this paper we describe the operation of an XUV high gain FEL operating within a bypass of an electron storage ring, and discuss the implications on storage ring optimization imposed by FEL requirements. It transpires that, in the parameter regime of interest, collective effects within the beam play an important role. For example, intrabeam scattering dilutes the transverse emittance of the beam and the microwave instability increases the momentum spread. Both phenomena reduce the effectiveness of the FEL. A computer code, ZAP, has been written which, for a given lattice design, takes all such effects into consideration and produces a figure of merit for FEL operation for that machine. We show the results of ZAP for several storage ring designs, all optimized for FEL operation, and present a design example of a facility capable of producing coherent radiation at 400 Å with tens of megawatts of peak power.
56152176
CEBAF-ER: Extending the Frontier of Energy Recovery at Jefferson Lab
A successful GeV scale energy recovery demonstration with a high ratio of peak-to-injection energies (50:1) was recently carried out on the CEBAF (Continuous Electron Beam Accelerator Facility) recirculating superconducting linear accelerator in an effort to address issues related to beam quality preservation in a large scale energy recovery system. To gain a quantitative understanding of the beam behavior through the machine, an intense effort was made to characterize the 6D phase space during the CEBAF-ER (CEBAF with Energy Recovery) experimental run. A scheme was implemented to measure the transverse emittance of the energy recovered beam prior to being sent to the dump, as well as in the injector and in each arc. The emittance provides a figure of merit in this context inasmuch as it characterizes the extent to which beam quality is preserved during energy recovery. In addition to describing the transverse phase space, the momentum spread was measured in the injector and arcs to characterize the longitudinal phase space. Measurements also included the RF system's response to the energy recovery process. And by using a novel technique employing wire scans in conjunction with PMTs (Photomultiplier Tubes) to accurately measure the beam profile at the dump, we can qualitativelymore » characterize beam preservation through the recirculator. One of the salient conclusions from the experiment is that the energy recovery process does not contribute to the emittance degradation since the emittance of the recirculating pass is consistent with that of the accelerating pass.« less
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.
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.
73153891
A Study on Some Special Forms of Holographic Ricci Dark Energy in Fractal Universe
We have considered the modified and the extended holographic Ricci 
dark energy models (MHRDE and EHRDE) in fractal universe. We have assumed a time-like 
fractal profile , where . We have reconstructed the Hubble parameter 
, the energy density, the equations of state parameter and the deceleration parameter for both MHRDE and EHRDE.
118408378
The generalized second law of thermodynamics in f(R) gravity for various choices of scale factor
The present study is aimed at investigating the validity of the generalized second law (GSL) of thermodynamics in f(R) gravity. Choosing f(R)=R+ξRμ+ζR−ν with ξ,μ,ζ, ν > 0 (following the study of Nojiri and Odintsov in 2003), we have computed the time derivatives of total entropy for various choices of scale factor pertaining to emergent, intermediate, and logamediate scenarios of the universe. We have taken into account the radii of Hubble, apparent, particle, and event horizons while computing the time derivatives of entropy under various situations being considered. After analyzing through the plots of time derivative of total entropy against cosmic time, it is observed that the derivative always stays at positive level. This indicates the validity of GSL of thermodynamics in the f(R) gravity irrespective of the choices of scale factor and enveloping horizon.
121605686
Anomalous increase in width of fission fragment mass distribution inF19+Th232
Fission fragment mass distribution has been studied for the system $^{19}\mathrm{F}+^{232}\mathrm{Th}$ over an energy range of $105.4\phantom{\rule{0.3em}{0ex}}\text{MeV}$ to $84.2\phantom{\rule{0.3em}{0ex}}\text{MeV}$ in laboratory frame. For energies, above the Coulomb barrier, the variance of the mass distributions ${\ensuremath{\sigma}}_{m}^{2}$ varies linearly with temperature of the fused system, signifying statistical fusion-fission reaction. However, as energy decreases through the Coulomb barrier, a rapid increase in ${\ensuremath{\sigma}}_{m}^{2}$ is observed for the first time which may be a signal of onset of orientation dependent quasifission reaction.
119793009
A holographic reconstruction of the modifiedf(R) Horava-Lifshitz gravity with scale factor in power-law form
This paper is devoted to the study of holographic reconstruction of the modified f(R) Horava-Lifshitz gravity in the flat universe. For this purpose, we assume a scale factor in the form of exact power-law solution. A reconstructed model is obtained which may provide reasonable qualitative description of some cosmological era satisfying the sufficient condition for a realistic model. We represent the graphical description of this model exhibiting increasing behavior. We also discuss the evolution of the accelerated expansion of the universe through equation of state parameter (EoS) for the reconstructed model. Its graphical representation depicts about a quintessence dominated era in near future. The stability of the model is observed initially, however it becomes unstable after a small interval of time.
123064298
Time of flight (TOF) spectrometer for accurate measurement of mass and angular distribution of fission fragments in heavy ion induced fission reactions
Abstract The performance of a dual time of flight (TOF) spectrometer using two 24 cm×10 cm area X – Y position sensitive Multi-Wire Proportional Counters (MWPC) is reported. Good separation of compound nuclear fission channel from elastic, quasi-elastic and non-compound fission channels have been achieved. Time calibration of the spectrometer using a technique, dependent on the detector independence of the mass or kinetic energy distributions gave a three times better mass resolutions compared to the conventional calibration technique using elastically scattered projectiles in a heavy ion induced fission reaction. Detail experimental methods in determining fission fragment mass and angular distribution have been presented and discussed.