32584478
Study of the Beam Breakup Mode in Linear Induction Accelerators for Heavy Ions
A simple theoretical study and numerical estimate is presented for the transverse amplitude growth of a nonrelativistic heavy ion beam in an induction linac, as envisaged for use in commercial power plants, due to the nonregenerative coherent beam breakup mode. An equivalent electrical circuit has been used to represent the accelerating induction modules. Our calculation shows that for the parameters of interest, the beam breakup amplitude for a heavy ion beam grows extremely slowly in the time scales of interest, to magnitudes insignificant for transport purposes. It is concluded that the coherent beam breakup mode does not pose any serious threat to the stability of a high current (kA) heavy ion beam in an induction linac.
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.
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
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
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.
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.
119115271
Acceleration of the Universe in presence of tachyonic field
Abstract
In this letter, we have assumed that the Universe is filled in tachyonic field with potential, which gives the acceleration of the Universe. For certain choice of potential, we have found the exact solutions of the field equations. We have shown the decaying nature of potential. From recently developed statefinder parameters, we have investigated the role of tachyonic field in different stages of the evolution of the 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
120207132
New holographic dark energy in modified f(R) Horava-Lifshitz gravity
In this paper, we study the new holographic dark energy model in the framework of modified f(R) Horava-Lifshitz Gravity. We apply correspondence scheme to construct model the in underlying scenario using power-law form of scale factor. To explore accelerated expansion of the universe, some well-known cosmological parameters (equation of state parameter and squared speed of sound) and cosmological planes (ωΛ–$\omega'_{\varLambda}$ and statefinder) are discussed for reconstructed model. It is interesting to conclude that these parameters represent phantom behavior of the universe with stable configuration. also, the cosmological planes show compatible results with recent observations for accelerated expansion of the universe.
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.
21552932
Real Time Global Tests of the ALICE High Level Trigger Data Transport Framework
The High Level Trigger (HLT) system of the ALICE experiment is an online event filter and trigger system designed for input bandwidths of up to 25 GB/s at event rates of up to 1 kHz. The system is designed as a scalable PC cluster, implementing several hundred nodes. The transport of data in the system is handled by an object-oriented data flow framework operating on the basis of the publisher-subscriber principle, being designed fully pipelined with lowest processing overhead and communication latency in the cluster. In this paper, we report the latest measurements where this framework has been operated on five different sites over a global north-south link extending more than 10,000 km, processing a ldquoreal-timerdquo data flow.