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Optimizing ring-based CSR sources

Description: Coherent synchrotron radiation (CSR) is a fascinating phenomenon recently observed in electron storage rings and shows tremendous promise as a high power source of radiation at terahertz frequencies. However, because of the properties of the radiation and the electron beams needed to produce it, there are a number of interesting features of the storage ring that can be optimized for CSR. Furthermore, CSR has been observed in three distinct forms: as steady pulses from short bunches, bursts from… more
Date: January 1, 2004
Creator: Byrd, J.M.; De Santis, S.; Hao, Z.; Martin, M.C.; Munson, D.V.; Li, D. et al.
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Partner: UNT Libraries Government Documents Department
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Electron-cloud build-up in hadron machines

Description: The first observations of electron-proton coupling effect for coasting beams and for long-bunch beams were made at the earliest proton storage rings at the Budker Institute of Nuclear Physics (BINP) in the mid-60's [1]. The effect was mainly a form of the two-stream instability. This phenomenon reappeared at the CERN ISR in the early 70's, where it was accompanied by an intense vacuum pressure rise. When the ISR was operated in bunched-beam mode while testing aluminum vacuum chambers, a resonan… more
Date: August 9, 2004
Creator: Furman, M. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Radionuclide Inventory Management at the New 100 MeV Isotope Production Facility at LANL

Description: The Isotope Production Facility (IPF) at Los Alamos is operated on the authorization basis of a radiological facility with an inventory limit of a Category 3 Nuclear Facility. For the commissioning of IPF, a ''dummy'' target stack containing Zn, Nb and Al disks, and a ''prototype'' stack were irradiated with a proton beam. The ''prototype'' stack contained two pressed RbCl disks, encapsulated in stainless steel, and a Ga metal target. Typical ''prototype'' stack beam parameters were 88.9 {micro… more
Date: October 3, 2004
Creator: Fassbender, M. E.; Phillips, D. R.; Nortier, F. M.; Trellue, H. R.; Hamilton, V. T.; Heaton, R. C. et al.
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Partner: UNT Libraries Government Documents Department
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Electron beam collector with a low back flow

Description: Generation of a DC electron beam in the future Fermilab electron cooler [1] employs an electrostatic acceleration and a beam energy recovery, so that electrons are decelerated from the nominal energy of 4.3 MeV they have in the cooling section to few keV in the collector. Stable performance of this scheme requires a current loss {delta}I below 10 {micro}A at the beam current up to the nominal value of I = 0.5 A. One of sources of the loss is a back flow of secondary electrons from the beam coll… more
Date: March 17, 2004
Creator: Shemyakin, A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Fermilab drift tube Linac revisited

Description: Using the PARMILA code running under PC-WINDOWS, the present performance of the Fermilab Drift Tube Linac has been analyzed in the light of new demands on the Linac/Booster complex (the Proton Source). The Fermilab Drift Tube Linac (DTL) was designed in the sixties as a proton linac with a final energy of 200 MeV and a peak current of 100mA. In the seventies, in order to enable multi-turn charge exchange injection into the Booster, the ion source was replaced by an H- source with a peak beam cu… more
Date: May 12, 2004
Creator: Popovic, Milorad
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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New waveguide-type HOM damper for ALS storage ring cavities.

Description: The ALS storage ring 500 MHz RF system uses two re-entrant accelerating cavities powered by a single 320kW PHILLIPS YK1305 klystron. During several years of initial operation, the RF cavities were not equipped with effective passive HOM damper systems. Longitudinal beam stability was achieved through cavity temperature control and the longitudinal feedback system (LFB), which was often operating at the edge of its capabilities. As a result, longitudinal beam stability was a significant operatio… more
Date: June 28, 2004
Creator: Kwiatkowski, Slawomir; Baptiste, Kenneth & Julian, James
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Partner: UNT Libraries Government Documents Department
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Measurement and simulation of the UMERbeam in the sourceregion

Description: As the beam propagates in the University of Maryland Electron Ring (UMER) complex transverse density structure including halos has been observed. A primary objective of the experiment is to understand the evolution of a space-charge-dominated beam as it propagates over a substantial distance. It is therefore important to understand which details of the beam structure result from propagation of the beam in the ring and which characteristics result from the specific details of the initial distrib… more
Date: June 11, 2004
Creator: Haber, I.; Bernal, S.; Kishek, R. A.; O'Shea, P. G.; Quinn, B.; Reiser, M. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Overview of Virtual National Labratory Objectives, Plans, and Projects

Description: Significant experimental and theoretical progress has been made in the U.S. heavy ion fusion program on high-current sources, transport, and focusing. Currents over 200 mA have been transported through a matching section and 10 half-lattice periods with electric quadrupoles. An experiment shows control of high beam current with an aperture, while avoiding secondary electrons. New theory and simulations of the neutralization of intense beam space charge with plasma in various focusing chamber co… more
Date: May 10, 2004
Creator: Logan, B.; Celata, C.; Kwan, J.; Lee, E.; Leitner, M.; Seidl, P. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Flash X-Ray (FXR) Accelerator Optimization - Beam-induced Voltage Simulation and TDR Measurements

Description: Lawrence Livermore National Laboratory (LLNL) is evaluating design alternatives to improve the voltage regulation in our Flash X-Ray (FXR) accelerator cell and pulse-power system. The goal is to create a more mono-energetic electron beam that will create an x-ray source with a smaller spot-size. Studying the interaction of the beam and accelerator cell will generate improved designs for high-current accelerators at Livermore and elsewhere. When an electron beam crosses the energized gap of an a… more
Date: April 7, 2004
Creator: Ong, M. M. & Vogtlin, G. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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LUMINOSITY OPTIMIZATION USING AUTOMATED IR STEERING AT RHIC.

Description: The goal of the RHIC 2004 Au-Au run was to maximize the achieved integrated luminosity. One way is to increase beam currents and minimize beam transverse emittances. Another important ingredient is the minimization of time spent on activities postponing the declaration of ''physics conditions'', i.e. stable beam conditions allowing the experimental detectors to take data. Since collision rates are particularly high in the beginning of the store the integrated luminosity benefits considerably fr… more
Date: July 5, 2004
Creator: DREES,A. D'OTTAVIO,T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Measurement of 107Ag(alpha,gamma)111 In Cross Sections

Description: Cross sections have been measured for the {sup 107}Ag({alpha},{gamma}){sup 111}In reaction at several a-particle energies between 7.8 MeV and 11.9 MeV. This reaction is of interest because it can provide a check on calculations of low-energy ({alpha},{gamma}) cross sections required for stellar nucleosynthesis predictions. Stacks of natural Ag foils of 1 mm thickness and 99.97% purity were bombarded with {sup 4}He{sup +} beams. Following irradiation, the yields of the 171-keV and 245-keV photon… more
Date: October 7, 2004
Creator: Baglin, C M; Norman, E B; Larimer, R & Rech, G A
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Effect of the electrostatic plasma lens on the emittance of ahigh-current heavy ion beam

Description: We describe measurements we have made of the emittance of a high-current, moderate-energy ion beam after transport through a permanent-magnet electrostatic plasma lens. The results indicate the absence of emittance growth due to the lens, when the lens is adjusted for optimal beam focusing. The measured emittance for a 16 keV Cu{sup 2+} ion beam formed by a vacuum arc ion source was about 0.4 {pi} {center_dot} mm {center_dot} mrad at a beam current of 50 mA rising more-or-less linearly to 1.5 {… more
Date: January 10, 2004
Creator: Chekh, Yu.; Goncharov, A.; Protsenko, I. & Brown, I.G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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ECLOUD04 workshop (Napa, California, April 19-23, 2004)

Description: As in previous workshops dealing with electron-cloud effects (KEK, July 1997; Santa Fe, February 2000; KEK, September 2001; CERN, April 2002), the focus of this workshop was broad, covering all aspects of the phenomena. The work presented at ECLOUD04 represented a significant advance relative to ECLOUD02 (CERN, April 2002). The systematic experimental program being carried out at the SPS for many years now, in preparation for LHC operation, keeps yielding valuable information particularly conce… more
Date: August 9, 2004
Creator: Furman, Miguel A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Diagnostics for intense heavy ion beams in the HIF-VNL

Description: Modern diagnostic techniques provide detailed information on beam conditions in injector, transport, and final focus experiments in the HIF-VNL. Parameters of interest include beam current, beam energy, transverse and longitudinal distributions, emittance, and space charge neutralization. Imaging techniques, based on kapton films and optical scintillators, complement and in some cases, may replace conventional techniques based on slit scans. Time-resolved optical diagnostics that provide 4-D tr… more
Date: June 11, 2004
Creator: Bieniosek, F. M.; Eylon, S.; Faltens, A.; Friedman, A.; Kwan, J. W.; Leitner, M. A. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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