45338774
Theory of Bunched Beam Stochastic Cooling
A theoretical description of the time-evolution of a bunched beam subjected to stochastic cooling is provided.
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.
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
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.
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.
118418724
Study of a tachyonic field and its statefinder diagnostics in various scenarios of the anisotropic universe
In the present work, we have considered N-dimensional Einstein field equations in which four-dimensional space- time is described by a Friedmann-Robertson-Walker metric and the extra d-dimensions by an Euclidean metric. By consid- ering the universe to be filled with a tachyonic field we have reconstructed the potential V(f) corresponding to the field re- constructions in an anisotropic universe under emergent - power law, emergent-intermediate, emergent-logamediate, and logamediate-intermediate scenarios. The statefinder parameters have been investigated in all of said scenarios. PACS Nos: 98.80.-k, 95.36.+x Resume : Nous considerons ici les equations de champ d'Einstein en N dimensions, ou l'espace-temps a quatre dimensions est decrit par une metrique Friedmann-Robertson-Walker et les d extra dimensions sont decrits par une metrique eucli- dienne. Considerant que l'univers est rempli de champs tachyoniques, nous avons reconstruit le potentiel V(f) qui corres- pond aux reconstructions de champ dans un univers anisotrope sous differents scenarios : emergent - loi de puissance, emergent-intermediaire, emergent-logamediaire et logamediaire-intermediaire. Nous analysons les parametres discriminants (statefinder) relies au facteur d'echelle cosmologique pour tous ces scenarios. (Traduit par la Redaction)
118375721
GENERALIZED SECOND LAW OF THERMODYNAMICS IN PRESENCE OF INTERACTING DBI ESSENCE AND OTHER DARK ENERGIES
In the present work we investigated the validity of the generalized second law (GSL) of thermodynamics in the presence of interaction between DBI-essence and other four candidates of dark energy, namely the modified Chaplygin gas, hessence, tachyonic field and new agegraphic dark energy. It has been observed that the GSL breaks down in the presence of the interactions. However, the event horizon remains to be an increasing function of time.
118422872
Statefinder and Om Diagnostics for Interacting New Holographic Dark Energy Model and Generalized Second Law of Thermodynamics
In this work, we have considered that the flat FRW universe is filled with the mixture of dark matter and the new holographic dark energy. If there is an interaction, we have investigated the natures of deceleration parameter, statefinder and Om diagnostics. We have examined the validity of the first and generalized second laws of thermodynamics under these interactions on the event as well as apparent horizon. It has been observed that the first law is violated on the event horizon. However, the generalized second law is valid throughout the evolution of the universe enveloped by the apparent horizon. When the event horizon is considered as the enveloping horizon, the generalized second law is found to break down excepting at late stage of the universe.
118945250
Interacting Ricci dark energy and its statefinder description
In this paper we have considered an interacting Ricci dark energy in flat Friedman-Robertson-Walker (FRW) universe. We have reconstructed the Hubble parameter under this interaction. Also, we have investigated the statefinder diagnostics. It has been revealed that the equation-of-state parameter behaves like quintessence in this interaction and from the statefinder diagnostics it has been concluded that the interacting Ricci dark energy interpolates between dust and ΛCDM stages of the universe.
56560251
A Study on the Interacting Ricci Dark Energy in f(R, T) Gravity
The present work reports study on the interacting Ricci dark energy in a modified gravity theory named f(R, T) gravity. In the specific model f(R, T) = μR + νT we have observed a quintom-like behavior of the equation of state parameter and a transition from matter dominated to dark energy density has been observed through fraction density evolution. The statefinder parameters reveal that the model interpolates between dust and $$\Uplambda\hbox{CDM}$$ΛCDM phases of the universe.