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STOCHASTIC COOLING FOR BUNCHED BEAMS.

Description: Problems associated with bunched beam stochastic cooling are reviewed. A longitudinal stochastic cooling system for RHIC is under construction and has been partially commissioned. The state of the system and future plans are discussed.
Date: May 16, 2005
Creator: BLASKIEWICZ, M.
Partner: UNT Libraries Government Documents Department

Antiproton stacking in the Recycler

Description: Possibilities to accumulate antiprotons in the Recycler are considered for three different cases: with current stochastic cooling, with upgraded stochastic cooling and with electron cooling. With stochastic cooling only, even upgraded, Recycler looks hardly useful. However, with electron cooling at its goal parameters and reasonably good vacuum in the Recycler, this machine would be efficient.
Date: June 23, 2003
Creator: Burov, Alexey
Partner: UNT Libraries Government Documents Department

Stochastic cooling overview

Description: The status of stochastic cooling and developments over the years are reviewed with reference to much of the original work. Both theoretical and technological subjects are considered.
Date: July 1, 2003
Creator: Marriner, John P
Partner: UNT Libraries Government Documents Department

Halo particle confinement in the VLHC using optical stochastic cooling

Description: Beam halo particles following the extreme trajectories near the physical aperture limit radiate Smith-Purcell radiation when moving over a diffraction grating. This grating can be used as a pick-up and a kicker for optical stochastic cooling of the halo particles. In this application cooling would have the effect of slowing down the halo particle diffusion onto the aperture. Cooling efficiency would quickly diminish with the distance from the aperture and would only affect the halo particles. A preliminary analysis of this system is considered.
Date: June 1, 2000
Creator: Zholents, Alexander; Barletta, W.; Chattopadhyay, S. & Zolotorev, M.
Partner: UNT Libraries Government Documents Department

Analysis of optical stochastic cooling including transverse effects

Description: The phase space area plays an important role in determining the performance of optical stochastic cooling. Specifically, the number of samples in the beam consists of three factors corresponding to three dimensions, the factor in each dimension being given by the ratio of the total phase space area in that dimension to the radiation wavelength.
Date: May 1, 1995
Creator: Kim, K.J. & Zege, A.V.
Partner: UNT Libraries Government Documents Department

Simple Lattice for the Precoo1er/Accumu1ator Scheme

Description: The Precoo1er/Accumu1ator scheme uses RF stacking to collect antiprotons produced by a mu1tipu1se proton extraction from the Main Ring. The stacking requires X{sub p} {approx} 2.5 m at the injection septum; therefore, a simple expansion of the present precoo1er lattice from {bar R} = 75 m to {bar R} = 101 m is not practical. It is possible that an appropriate high-X{sub p} insertion could be designed so that the increase in {gamma}{sub T} from the larger ring would cancel the decrease caused by the insertion, but one may wish also to consider lowering {gamma}{sub T} to run the ring always above transition so that the {bar p} acceleration could go not to 8 GeV but something on the order of 22 GeV thereby avoiding transition in the Main Ring and helping the Main Ring aperture bottleneck. This note discusses the possibility of a simple FODO lattice with missing magnets for dispersion killing and the stochastic cooling straight sections. For transverse cooling one would need to replace the FODO straight sections with high {beta} drifts to keep the phase advance over the cooling section sufficiently small. The same type of insertion as used in the current precoo1er design could be employed in the proposed lattice as well.
Date: October 23, 1980
Creator: MacLachlan, James
Partner: UNT Libraries Government Documents Department

Observation of the Coalescing of Beam Into an Asymmetric RF Bucket by Stochastic Cooling

Description: Antiprotons in the debuncher ring at Fermilab have been observed to be bunched outside of the 'barrier bucket' when cooled to small {Delta}p/p with the stochastic cooling. This bunching occurs in the same location as a very small stable bucket in the RF wave form. The stochastic cooling appears to be causing beam that is originally uniformly distributed to be captured by this stable bucket.
Date: January 1, 1993
Creator: Halling, Alfred Mike; Lu, Xian Ping & /Fermilab
Partner: UNT Libraries Government Documents Department

Design of Microwave Band Pass Filters for the Debuncher Stochastic Cooling System

Description: The FIR filters designed for the debuncher stochastic cooling system needed improvement. Its bandwidth was too wide, its magnitude was not flat, its phase ripple was too great, and it was difficult to control the characteristics of the filter. A simple microwave technique was employed to have a short time delay, simple robust layout, and small board size. A significant savings was seen over the FIR technique and these filters were installed in the Antiproton Source Debuncher while the FIR filters were removed from the debuncher stochastic cooling entirely.
Date: January 1, 2001
Creator: Deibele, C.
Partner: UNT Libraries Government Documents Department

A discussion of bunched beam stochastic cooling

Description: The analysis of Herr and Mohl[1] is used as a basis for a discussion of bunched beam cooling in the Fermilab recycler and the Tevatron. Differences between the two cooling regimes are discussed. Criteria discussed in that paper imply the failure of stochastic cooling in the Tevatron while permitting the success of stochastic cooling in the Recycler. These ''predictions'' are in agreement with observations.
Date: August 1, 2005
Creator: Neuffer, David
Partner: UNT Libraries Government Documents Department

Stochastic Cooling with Schottky Band Overlap

Description: Optimal use of stochastic cooling is essential to maximize the antiproton stacking rate for Tevatron Run II. Good understanding and characterization of the cooling is important for the optimization. The paper is devoted to derivation of the Fokker-Planck equations justified in the case of near or full Schottky base overlap for both longitudinal and transverse coolings.
Date: December 1, 2005
Creator: Lebedev, Valeri
Partner: UNT Libraries Government Documents Department

Integrals for IBS and beam cooling

Description: Simulation of beam cooling usually requires performing certain integral transformations every time step or so, which is a significant burden on the CPU. Examples are the dispersion integrals (Hilbert transforms) in the stochastic cooling, wake fields and IBS integrals. An original method is suggested for fast and sufficiently accurate computation of the integrals. This method is applied for the dispersion integral. Some methodical aspects of the IBS analysis are discussed.
Date: January 1, 2005
Creator: Burov, A.
Partner: UNT Libraries Government Documents Department

STOCHASTIC COOLING OF HIGH-ENERGY BUNCHED BEAMS

Description: Stochastic cooling of 100 GeV/nucleon bunched beams has been achieved in the Relativistic Heavy Ion Collider (RHIC). The physics and technology of the longitudinal cooling system are discussed, and plans for a transverse cooling system are outlined.
Date: June 25, 2007
Creator: BLASKIEWICZ,M. & BRENNAN, J.M.
Partner: UNT Libraries Government Documents Department

A SPLIT-FUNCTION LATTICE FOR STOCHASTIC COOLING.

Description: Lattice for a 3-GeV cooler ring with split functions is presented. The ring consists of two half-rings of different properties: in one half-ring, the phase-slip factor is near-zero; in the other half-ring, the phase-slip factor is large. The near-zero phase slip minimizes the 'bad mixing' between the stochastic-cooling pick-ups and kickers, while the high phase slip maximizes the 'good mixing' between the kickers and the next-turn pick-ups.
Date: September 10, 2007
Creator: WEI,J.
Partner: UNT Libraries Government Documents Department

BUNCHED BEAM STOCHASTIC COOLING SIMULAITONS AND COMPARISON WITH DATA

Description: With the experimental success of longitudinal, bunched beam stochastic cooling in RHIC it is natural to ask whether the system works as well as it might and whether upgrades or new systems are warranted. A computer code, very similar to those used for multi-particle coherent instability simulations, has been written and is being used to address these questions.
Date: September 10, 2007
Creator: BLASKIEWICZ,M. & BRENNAN, J.M.
Partner: UNT Libraries Government Documents Department

Vacuum Consideration Pertaining to Bellows Changes on Debuncher Tanks

Description: It has been proposed that the stochastic cooling tanks in the Debuncher be modified so that their position can be changed remotely by installing motor driven stands. The present bellows that connect the tanks to the beam pipe vacuum chamber does not have enough radial movement to allow the movement required of the tanks. In order for this proposal to be enacted, the existing bellows will have to be replaced. The present bellows is a formed bellows 5 1/2-inch I.D. x 2-inch long, it will be replaced by a welded bellows 4-inch I.D. x 4-inch long. Due to the smaller size of the replacement bellows, its effect on the performance of the Debuncher Vacuum System must be examined. The areas of concern are: pumpdown time, pressure attained by turbos, and pressure in the high vacuum range.
Date: November 13, 1985
Creator: Klen, J.
Partner: UNT Libraries Government Documents Department

Radio Frequency Notch Filter Utilizing Fiber Optic Laser Diode Delay Line

Description: A wide band, laser-diode/fiber-optic transmission line (FOL) has been developed which represents a potentially useful stochastic cooling notch filter element. Because of its small size and lack of need for sophisticated support equipment the FOL presents a viable alternative to both conventional and super conducting coaxial line notch filters. This note summarizes the characteristics of the FOL and of notch filter performance achieved with its use.
Date: April 1, 1985
Creator: Konecny, R.
Partner: UNT Libraries Government Documents Department

Synchrotron frequency spread independence of bunched-beam stochastic cooling at the Fermilab Recycler

Description: It is generally accepted that longitudinal stochastic cooling of bunched beams is not possible without a synchrotron frequency spread. Experiments in the Recycler storage ring (Fermilab) demonstrate the opposite: with an antiproton bunch in a parabolic potential well (no synchrotron frequency spread), the cooling was almost as efficient as in a trapezoidal potential well (with a relative synchrotron frequency spread of {approx} 100%). A possible explanation is that, at Recycler parameters, diffusion processes are sufficient to provide particle mixing.
Date: November 1, 2005
Creator: Broemmelsiek, D.; Burov, Alexey V.; Nagaitsev, S.; Neuffer, D. & /Fermilab
Partner: UNT Libraries Government Documents Department

Performance and upgrades of the Fermilab Accumulator stacktail stochastic cooling

Description: We report on the performance and planned upgrades to the Fermilab Accumulator Stacktail Stochastic Cooling System. The current system has achieved a maximum flux of 16.5e10/hour, limited by the input flux of antiprotons. The upgrades are designed to handle flux in excess of 40e10/hour.
Date: November 1, 2005
Creator: Derwent, P.F.; Cullerton, Ed; McGinnis, David; Pasquinelli, Ralph; Sun, Ding; Tinsley, David et al.
Partner: UNT Libraries Government Documents Department

IBS in a CAM-Dominated Electron Beam

Description: We report on the performance and planned upgrades to the Fermilab Accumulator Stacktail Stochastic Cooling System. The current system has achieved a maximum flux of 16.5e10/hour, limited by the input flux of antiprotons. The upgrades are designed to handle flux in excess of 40e10/hour.
Date: December 1, 2005
Creator: Burov, Alexey V.; /Fermilab; Gusachenko, I.; U., /Novosibirsk State; Nagaitsev, S.; /Fermilab et al.
Partner: UNT Libraries Government Documents Department

Cooling in a compound bucket

Description: Electron cooling in the Fermilab Recycler ring is found to create correlation between longitudinal and transverse tails of the antiproton distribution. By separating the core of the beam from the tail and cooling the tail using 'gated' stochastic cooling while applying electron cooling on the entire beam, one may be able to significantly increase the overall cooling rate. In this paper, we describe the procedure and first experimental results.
Date: September 1, 2007
Creator: Shemyakin, A.; Bhat, C.; Broemmelsiek, D.; Burov, A.; Hu, M. & /Fermilab
Partner: UNT Libraries Government Documents Department

RHIC progress and future

Description: The talk reviews RHIC performance, including unprecedented manipulations of polarized beams and recent low energy operations. Achievements and limiting factors of RHIC operation are discussed, such as intrabeam scattering, electron cloud, beam-beam effects, magnet vibrations, and the efficiency of novel countermeasures such as bunched beam stochastic cooling, beam scrubbing and chamber coatings. Future upgrade plans and the pertinent R&D program will also be presented.
Date: May 4, 2009
Creator: Montag,C.
Partner: UNT Libraries Government Documents Department

Stochastic cooling in RHIC

Description: After the success of longitudinal stochastic cooling of bunched heavy ion beam in RHIC, transverse stochastic cooling in the vertical plane of Yellow ring was installed and is being commissioned with proton beam. This report presents the status of the effort and gives an estimate, based on simulation, of the RHIC luminosity with stochastic cooling in all planes.
Date: May 4, 2009
Creator: Brennan,J.M.; Blaskiewicz, M. M. & Severino, F.
Partner: UNT Libraries Government Documents Department