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Pressure bump instability in very large cold bore storage rings

Description: Calculations have been done to estimate the circulating current necessary to induce the onset of a pressure bump instability in a cold bore storage ring. For a wide range of storage ring parameters, the instability threshold current is more than an order of magnitude higher than the operating current. 4 references, 2 tables.
Date: December 1, 1983
Creator: Limon, P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Design study for a high-current, steady-state autoresonant accelerator. Final report, July 14-November 14, 1979

Description: During the past year and a half, both theoretical and engineering investigations have been carried forward in a research program to assess the feasibility, and provide conceptual designs and engineering design studies for high current, steady state Auto-Resonant Accelerators. The behavior of each of the various components of an Auto-Resonant Accelerator has been carefully examined for the case of moderately relativistic electron energy and high electron current which will be appropriate for ste… more
Date: December 1, 1979
Creator: Drummond, W. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Rehyd development and installation report

Description: Rehyd, a low-impedance, HYDRA-type, water transmission line for bremsstrahlung exposures, was installed on the north side of the REBA facility. Rehyd produces 300 kA beams of 1.2 MeV electrons with a pulse width of 170 ns. Nominal x-ray exposure dose capabilities of 7 cal/g and 20 to 25 kJ were realized thus far. A description is given of the specific design parameters and facility layouts including the unique features of the REBA Marx generator/Rehyd line energy-transfer system. Diode configur… more
Date: December 1, 1977
Creator: Schuch, R. L. & Woodall, H. N.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Development of pulsed processes for the manufacture of solar cells. [Ion implantation and annealing process]

Description: This report describes the results of a 1-year program to develop the processes required for low-energy ion implantation for the automated production of silicon solar cells. The program included (1) demonstrating state-of-the-art ion implantation equipment and designing an automated ion implanter, (2) making efforts to improve the performance of ion-implanted solar cells to 16.5 percent AM1, (3) developing a model of the pulse annealing process used in solar cell production, and (4) preparing an… more
Date: December 1, 1978
Creator: Minnucci, J. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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New Cyclotron Targetry to Enhance F-18 clinical Position Emission Tomography

Description: This project proposes to develop cyclotron targets that produce F-18 for clinical Positron Emission Tomography (PET) at significantly higher rates than that available from current targetry. This production rate of 18F is directly proportional to the beam current. Higher beam currents would result in increased 18F production but would be accompanied by higher heat loads to the target. The beam power available in most commercial cyclotrons exceeds the heat removal capacity of current target techn… more
Date: December 19, 2008
Creator: Doster, J. Michael
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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SLIM, Short-pulse Technology for High Gradient Induction Accelerators

Description: A novel short-pulse concept (SLIM) suited to a new generation of a high gradient induction particle accelerators is described herein. It applies advanced solid state semiconductor technology and modern microfabrication techniques to a coreless induction method of charged particle acceleration first proven on a macro scale in the 1960's. Because this approach avoids use of magnetic materials there is the prospect of such an accelerator working efficiently with accelerating pulses in the nanoseco… more
Date: December 16, 2008
Creator: Arntz, Floyd; Kardo-Sysoev, A. & Krasnykh, A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Operating experience with the LBL ECR source

Description: The overall performance of the LBL ECR source in providing beam for the 88-Inch Cyclotron has been excellent. However, during the past two years there have been some fluctuations in the peak performance, particularly for the highest charge states. Among the factors which influence the peak performance are coatings from solid feeds or gases such as SiH/sub 4/ or CO/sub 2/, changes in first stage output, and variation in outgassing rates on the wall. Modifications made to the source have also aff… more
Date: December 1, 1987
Creator: Lyneis, C.M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Energy and technology review

Description: Research programs at Lawrence Livermore Laboratories are described. These include: the generation of intense electron beams for military applications; SYNROC, a permanent means of radioactive-waste storage in synthetic rock compounds; and studies of respiration using a positron camera with radioisotopes produced in the 100-MeV electron linear accelerator. (GHT)
Date: December 1, 1981
Creator: Stowers, I. F.; Crawford, R. B.; Esser, M. A. & Neal, E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Space-charge limits in linear accelerators

Description: This report presents equations that allow an approximate evaluation of the limiting beam current for a large class of radio-frequency linear accelerators, which use quadrupole strong focusing. Included are the Alvarez, the Wideroe, and the radio-frequency quadrupole linacs. The limiting-current formulas are presented for both the longitudinal and the transverse degrees of freedom by assuming that the average space-charge force in the beam bunch arises from a uniformly distributed charge within … more
Date: December 1, 1980
Creator: Wangler, T. P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Near spherical illumination of ion-beam and laser targets

Description: A procedure is developed for reducing energy-deposition asymmetry in spherical targets driven directly by ion or laser beams. This work is part of a strategy for achieving illumination symmetry in such targets, which is proposed as an alternative to those in the literature. This strategy allows an axially symmetric placement of beamlets, which would be convenient for some driven or reactor scenarios. It also allows the use of beam currents or energy fluxes and beam transverse profiles to help r… more
Date: December 12, 1985
Creator: Mark, J.W.K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Novel methods of copper vapor laser excitation

Description: Microwave and intense electron beam excitation of copper vapor are being investigated to be used in copper vapor lasers for isotope separation. Both methods use copper chloride vapor by heating copper chloride. Helium was used as the buffer gas at 2 to 100 torr. In the microwave system, intense copperlines at 510 nm and 578 nm were observed. Initial electron beam results indicate that light emission follows the beam current.
Date: December 31, 1990
Creator: McColl, W. B.; Ching, H.; Bosch, R.; Brake, M. & Gilgenbach, R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Production of Actinium-225 via High Energy Proton Induced Spallation of Thorium-232

Description: The science of cancer research is currently expanding its use of alpha particle emitting radioisotopes. Coupled with the discovery and proliferation of molecular species that seek out and attach to tumors, new therapy and diagnostics are being developed to enhance the treatment of cancer and other diseases. This latest technology is commonly referred to as Alpha Immunotherapy (AIT). Actinium-225/Bismuth-213 is a parent/daughter alpha-emitting radioisotope pair that is highly sought after becaus… more
Date: December 30, 2011
Creator: Harvey, James & Jerry Nolen, George Vandegrift, Itacil Gomes, Tom Kroc, Phil Horwitz, Dan McAlister, Del Bowers, Vivian Sullivan, John Greene
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The ecloud measurement setup in the Main Injector

Description: Ecloud has been observed in many high intensity accelerators which can limit the amount of current that can be stored in them. In particular, for ProjectX, the amount of beam current that will be stored in the MI (Main Injector) will be {approx}160 x 10{sup 12} protons while the present maximum intensity is {approx}45 x 10{sup 12} protons which is about 3.5x less beam. Although ecloud has been observed in the MI, it has not caused instabilities at the present running conditions. However, there … more
Date: December 1, 2010
Creator: Tan, C.Y.; Backfish, M.; Zwaska, R. & /Fermilab
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Analysis of Vernier Scans during the PP2PP run in 2009 (pp at 100 GeV/beam)

Description: At the end of RHIC's 2009 operation a dedicated run for the PP2PP experiment (part of the STAR experiment) took place from Jun 29 to Jul 06 2009. Polarized protons were accelerated to 100 GeV using ramp-file pp100-90pp2pp with a {beta}* = 22 m in IR6. Since only transverse polarization was required no rotator ramp was in use. The PP2PP experiment consists mainly of two Roman Pot detectors (one horizontal and one vertical) on either side of IR6 in the outgoing-beam arms between the Q3 and Q4 mag… more
Date: December 13, 2011
Creator: Drees, A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Observation of Beam ION Instability in Spear3

Description: Weak vertical coupled bunch instability with oscillation amplitude at {mu}m level has been observed in SPEAR3. The instability becomes stronger when there is a vacuum pressure rise by partially turning off vacuum pumps and it becomes weaker when the vertical beam emittance is increased by turning off the skew quadrupole magnets. These confirmed that the instability was driven by ions in the vacuum. The threshold of the beam ion instability when running with a single bunch train is just under 20… more
Date: December 14, 2011
Creator: Teytelman, D.; Cai, Y.; Corbett, W. J.; Raubenheimer, T. O.; Safranek, J. A.; Schmerge, J. F. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Status of PEP-X Light Source Design Study

Description: The SLAC Beam Physics group and other SLAC collaborators continue to study options for implementing a near diffraction-limited ring-based light source in the 2.2-km PEP-II tunnel that will serve the SSRL scientific program in the future. The study team has completed the baseline design for a 4.5-GeV storage ring having 160 pm-rad emittance with stored beam current of 1.5 A, providing >10{sup 22} brightness for multi-keV photon beams from 3.5-m undulator sources. The team has also investigate… more
Date: December 14, 2011
Creator: Bane, K. L. F.; Bertsche, K. J.; Cai, Y.; Chao, A.; Huang, X.; Jiao, Y. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Debuncher Momentum Cooling Systems Signal to Noise Measurements

Description: The Debuncher Momentum cooling systems were carefully measured for signal to noise. It was observed that cooling performance was not optimum. Closer inspection shows that the installed front-end bandpass filters are wider than the pickup response. (The original filters were specified to be wider so that none of the available bandwidth would be clipped.) The end result is excess noise is amplified and passed onto the kickers unimpeded, hence, reducing the achievable system gain. From this data, … more
Date: December 18, 2001
Creator: Pasquinelli, Ralph J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Progress on the PSR/LANSCE upgrade

Description: A two-phased improvement program for the spallation neutron facilities at LANSCE is underway and scheduled to be completed early in 1998. The primary goals are a beam reliability or availability of 85% or greater, a capability for routine and sustained beam operations for eight months per year, access to the experimental room (ER-1) closest to the neutron production target with beam on, and 100 {mu}A average beam current from PSR. Many reliability improvements are included in the project along … more
Date: December 1, 1995
Creator: Macek, R.J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Beam instrumentation in the AGS Booster

Description: The AGS Booster was designed to accelerate low intensity (2 {times} 10{sup 10}) polarized protons, high intensity (1.5{times}10{sup 13}) protons and heavy ions through Au{sup +33}. Coping with this wide range of beams, the 3 {times} 10{sup {minus}11} Torr vacuum and the radiation environment presented challenges for the beam monitors. Some of the more interesting instrumentation design and performance during the recent Booster proton commissioning will be described.
Date: December 31, 1991
Creator: Witkover, R. L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Design and initial tests of beam current monitoring systems for the APS transport lines

Description: The non-intercepting beam current monitoring systems suitable for a wide, range of beam parameters have been developed for the Advanced Photon Source (APS) low energy transport lines and high energy transport line. The positron or electron beam pulse in the transport lines wig have peak beam currents ranging from 8 mA to 29 A with pulse widths varying from 120 ps to 30 ns and pulse repetition rates from 2 Hz to 60 Hz. The peak beam current or total beam charge is measured with the fast or integ… more
Date: December 1, 1992
Creator: Wang, Xucheng
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The effects of proton beam quality on the production of gamma rays for nuclear resonance absorption in nitrogen

Description: We describe a method for performing nuclear resonance absorption with the proton beam from a radio frequency quadrupole (RFQ) linear accelerator. The objective was to assess the suitability of the pulsed beam from an RFQ to image nitrogen relative to that of electrostatic accelerators. This choice of accelerator results in tradeoffs in performance and complexity in return for the prospect of higher average current. In spite of a reduced resonance attenuation coefficient in nitrogen, we successf… more
Date: December 1, 1993
Creator: Morgado, R. E.; Cappiello, C. C. & Dugan, M. P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Beam Loading in a High Current Accelerating Gap

Description: Energy exchange between a high-current beam and a source at an accelerating gap is treated with a simple transmission line theory. There exists a matching condition for which the beam energy gain is equal to the source voltage. The total energy gain in a multigap system is expressed in terms of individual source voltages and the beam current.
Date: December 31, 1991
Creator: Rhee, M. J. & Ding, B. N.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Vacuum behavior of the x-ray lithography source

Description: Photon stimulated desorption, PSD, is the major source of the gas load in electron storage rings and therefore strongly influences both beam lifetime and beam quality. The 200 MeV compact ring at the NSLS is an ideal tool to study PSD since its energy can be varied from 60 to 200 MeV and the photoelectrons produced by synchrotron radiation can be measured in clearing electrodes installed to collect trapped ions. Using these electrodes we show: (1) photoelectrons are produced only by photons hav… more
Date: December 31, 1991
Creator: Halama, H. J. & Murphy, J. B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Chromaticity of the lattice and beam stability in energy-recovery linacs

Description: Energy recovery linacs (ERLs) are an emerging generation of accelerators promising to revolutionize the fields of high-energy physics and photon sciences. These accelerators combine the advantages of linear accelerators with that of storage rings, and hold the promise of delivering electron beams of unprecedented power and quality. Use of superconducting radio-frequency (SRF) cavities converts ERLs into nearly perfect 'perpetuum mobile' accelerators, wherein the beam is accelerated to a desirab… more
Date: December 23, 2011
Creator: Litvinenko, V. N.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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