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Contributions to the second workshop on medium energy electron cooling - MEEC96

Description: MEEC96 was a workshop devoted primarily to discussion within four working groups, not a mini-conference of prepared reports. Therefore, although there are contributions bearing the name of a single author, much of what was learned came in extemporaneous discussion of the issues posed to the participants. The original plan to produce formal proceedings has been dropped because of the limited number of participants willing to write up their own contributions and because of the difficulty of converting free-wheeling discussion to the written word. The premsise for the 1996 gathering was to set a critique of Fermilab`s R&D effort at cooling a ring of 8 GeV {bar p}`s. Separate abstracts have been submitted to the energy database for contributions to this workshop.
Date: September 1, 1997
Creator: MacLachlan, J.
Partner: UNT Libraries Government Documents Department

Tolerable Beam Loss at High-Intensity Machines

Description: Tolerable beam losses are estimated for high-intensity ring accelerators with proton energy of 3 to 16 GeV. Dependence on beam energy, lattice and magnet geometry is studied via full Monte Carlo MARS14 simulations in lattice elements, shielding, tunnel and surrounding dirt with realistic geometry, materials and magnetic fields.
Date: August 28, 2000
Creator: Oleg E. Krivosheev, Nikolai V. Mokhov
Partner: UNT Libraries Government Documents Department

Polarized structure functions of the nucleon in the resonance region

Description: Aspects of the spin structure functions of proton and neutrons at low momentum transfer Q{sup 2} and energy transfer, {nu}, i.e. in the region of the nucleon resonances are discussed. Experiments to measure A{sub 1}{sup p}, A{sub 2}{sup p} and A{sub 1}{sup n} structure functions at CEBAF in a Q{sup 2} range from 0.15 to 2.0 GeV{sup 2}, and a W range from threshold to 2.2 GeV are presented.
Date: January 1, 1994
Creator: Burkert, Volker
Partner: UNT Libraries Government Documents Department

Radioisotope yields from 1.85-GeV protons on Mo and 1.85- and 5.0-GeV protons on Te

Description: Radioisotope yields from 1.85-GeV proton interactions in a natural isotopic composition Mo target and those from 1.85- and 5.0-GeV protons in natural Te targets were measured at Lawrence Berkeley Laboratory`s Bevatron. The radioisotope yields were determined by {gamma}-counting the targets using a 100-cm{sup 3} coaxial Ge detector following the irradiations. Cross sections were determined for the production of 31 radioactive nuclides, ranging from Z = 35, A = 74, to Z = 43, A = 97, from the Mo target and for 47 radioactive nuclides, ranging from Z = 35, A = 75, to Z = 53, A = 130 from the Te targets.
Date: May 1, 1995
Creator: Bardayan, D.W.; Hindi, M.M. & Barghouty, A.F.
Partner: UNT Libraries Government Documents Department

Fixed field circular accelerator designs

Description: The rapid rate and cycle time required to efficiently accelerate muons precludes conventional circular accelerators. Recirculating linacs provide one option, but the separate return arcs per acceleration pass may prove costly. Recent work on muon acceleration schemes has concentrated on designing fixed-field circular accelerators whose strong superconducting fields can sustain a factor of 4 increase in energy from injection to extraction. A 4 to 16 GeV fixed-field circular accelerator has been designed which allows large orbit excursions and the tune to vary as a function of momentum. Acceleration is .6 GeV per turn so the entire cycle consists of only 20 turns. In addition, a 16 to 64 GeV fixed-field circular accelerator has been designed which is more in keeping with the traditional Fixed Field Alternating Gradient machines. In this work the two machine designs are described.
Date: January 6, 2000
Creator: Johnstone, C.; Wan, W. & Garren, A.
Partner: UNT Libraries Government Documents Department

SC driver linac for a rare isotope facility.

Description: An ion linac formed of superconducting rf cavities can provide a multi-beam driver accelerator for the production of nuclei far from stability. A multi-beam driver supports a wide variety of production reactions and methods. This paper outlines a concept for a 1.3 GV linac capable of delivering several hundred kilowatts of uranium beam at an energy of 400 MeV per nucleon. The linac would accelerate the full mass range of ions, and provide higher velocities for the lighter ions, for example 730 MeV for protons. The accelerator will consist of an ECR ion source injecting a normally conducting RFQ and four short IH structures, then feeding an array of more than 400 superconducting cavities of six different types, which range in frequency from 58 to 700 MHz. A novel feature of the linac is the acceleration of beams containing more than one charge state through portions of the linac, in order to maximize beam current for the heavier ions. Such operation is made feasible by the large transverse and longitudinal acceptance provided by the large aperture and high gradient which are characteristic of superconducting rf cavities.
Date: December 10, 1999
Creator: Shepard, K. W.; Delayen, J. R.; Lyneis, C. M.; Nolen, J.; Ostroumov, P.; Staples, J. W. et al.
Partner: UNT Libraries Government Documents Department

The PEP-II project: Design status and R&D results

Description: The PEP-II project, a joint proposal of SLAC, LBL, and LLNL, will involve an upgrade of the PEP storage ring at SLAC to serve as an asymmetric B factory. The upgrade will involve replacing the vacuum and rf systems of PEP, which will serve as the high-energy ring (containing 9 GeV electrons), along with the addition of a new low-energy ring (containing 3.1 GeV positrons) mounted atop the high-energy ring. The present design status of the project and a summary of recent R&D results are presented here. If approved, the PEP-II project is ready to begin construction in October 1993.
Date: July 1, 1993
Creator: Zisman, M. S.
Partner: UNT Libraries Government Documents Department

Observation of a Broad Structure in the $\pi^+\pi^-J/\psi$ Mass Spectrum around 4.26~GeV/$c^2$

Description: The authors study initial-state radiation events, e{sup +}e{sup -} {yields} {gamma}{sub ISR} {pi}{sup +}{pi}{sup -} J/{psi}, with data collected with the BABAR detector. They observe an accumulation of events near 4.26 GeV/c{sup 2} in the invariant-mass spectrum of {pi}{sup +}{pi}{sup -} J/{psi}. Fits of the mass spectrum indicate that a broad resonance with a mass of about 4.26 GeV/c{sup 2} is required to describe the observed structure. The presence of additional narrow resonances cannot be excluded. The fitted width of the broad resonance is 50 to 90 MeV/c{sup 2}, depending on the fit hypothesis.
Date: July 6, 2005
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
Partner: UNT Libraries Government Documents Department