46604095
X-Ray Based Subpicosecond Electron Bunch Characterization Using 90 degrees Thomson Scattering.
LBNL-39060 UC·414 Preprint ERNEST ORLANDO LAWRENCE BERKELEY N.ATIONAL LABORATORY X-Ray Based Sub-Picosecond Electron Bunch Characterization Using 90° Thomson Scattering W. Leemans, R.W. Schoenlein, P. Volfbeyn, A. Chin, T.E. Glover, P. Balling, M. Zolotorev, K.]. Kim, S. Chattopadhyay, and C.V. Shank Accelerator and Fusion Research Division June 1996 Submitted to Physical Review Letters OJ (,Q U1 lSl r- r- ID j 0 lll U j'< o-O r- Z OJ w I lSl N lSl
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
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
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.
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.
17525841
Probing supergravity grand unification in the Brookhaven g-2 experiment.
A quantitative analysis of ${\mathit{a}}_{\mathrm{\ensuremath{\mu}}}$\ensuremath{\equiv}1/2(g-2${)}_{\mathrm{\ensuremath{\mu}}}$ within the framework of supergravity grand unification and radiative breaking of the electroweak symmetry is given. It is found that ${\mathit{a}}_{\mathrm{\ensuremath{\mu}}}^{\mathrm{SUSY}}$ is dominated by the chiral interference term from the light chargino exchange, and that this term carries a signature which correlates strongly with the sign of \ensuremath{\mu}. Thus as a rule ${\mathit{a}}_{\mathrm{\ensuremath{\mu}}}^{\mathrm{SUSY}}$g0 for \ensuremath{\mu}g0 and ${\mathit{a}}_{\mathrm{\ensuremath{\mu}}}^{\mathrm{SUSY}}$0 for \ensuremath{\mu}0 with very few exceptions when tan\ensuremath{\beta}\ensuremath{\sim}1. At the quantitative level it is shown that if the E821 BNL experiment can reach the expected sensitivity of 4\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}10}$ and there is a reduction in the hadronic error by a factor of 4 or more, then the experiment will explore a majority of the parameter space in the ${\mathit{m}}_{0}$-${\mathit{m}}_{\mathit{g}\mathrm{\ifmmode \tilde{}\else \~{}\fi{}}}$ plane in the region ${\mathit{m}}_{0}$\ensuremath{\lesssim}400 GeV, ${\mathit{m}}_{\mathit{g}\mathrm{\ifmmode \tilde{}\else \~{}\fi{}}}$\ensuremath{\lesssim}700 GeV for tan\ensuremath{\beta}\ensuremath{\gtrsim}10 assuming the experiment will not discard the standard model result within its 2\ensuremath{\sigma} uncertainty limit. For smaller tan\ensuremath{\beta}, the SUSY reach of E821 will still be considerable. Further, if no effect within the 2\ensuremath{\sigma} limit of the standard model value is seen, then large tan\ensuremath{\beta} scenarios will be severely constrained within the current naturalness criterion, i.e., ${\mathit{m}}_{0}$,${\mathit{m}}_{\mathit{g}\mathrm{\ifmmode \tilde{}\else \~{}\fi{}}}$\ensuremath{\lesssim}1 TeV. \textcopyright{} 1996 The American Physical Society.
31583612
Inclusion of fluctuations in Boltzmann-Uehling-Uhlenbeck dynamics: A method of simulation.
31869814
Heat partition in damped reactions.
The effect of driving force on the division of excitation energy between the asymmetric colliding partners in deep inelastic heavy-ion collisions is studied in the nucleon-exchange model. For this purpose an event-by-event analysis using Monte Carlo simulation technique is performed. It is seen that the fraction of the total excitation energy carried by the projectile-like fragment is sensitive to the mass drift. The model is also applied to analyze the correlation between fragment mass and excitation energy for a given total energy loss and significant correlation is found. The reactions induced by {sup 56}Fe at 9 MeV/nucleon and {sup 74}Ge at 8.5 MeV/nucleon on {sup 165}Ho are considered in our analysis and the calculated correlations are in good agreement with the results obtained from the kinematic coincidence experiments.
38532982
Effect of trajectory fluctuations on nucleon drift and diffusion in deep inelastic heavy ion collisions.
The role of trajectory fluctuations on the first and second moments obtained in the mean trajectory approximation for the proton and neutron distributions of the projectile-like fragments produced in deep inelastic heavy ion collisions has been studied in the framework of stochastic transfer of single nucleons. At each instant of time the neutron and proton numbers of the colliding nuclei are considered to be given by dynamically evolving Gaussian distributions generating trajectory fluctuations. The first moments calculated in this method differ considerably from those obtained in the mean trajectory approximation for the systems with strong gradient in the driving force around the point of injection. The second moments, however, do not change appreciably for all the systems studied.