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Polarized H/sup -/ sources for the AGS - present and future

Description: The AGS polarized H/sup -/ source presently produces 30 to 40 ..mu..A of vector H/sup -/ in 500 ..mu..s pulses, with a polarization of 70-75%. The source operates reliably and has been used for polarized physics runs the past two years. There is now a development program in progress which has as its goal an operational vector H/sup -/ source producing milliamperes of current for the AGS.
Date: January 1, 1986
Creator: Alessi, J.G.; Kponou, A. & Sluyters, T.
Partner: UNT Libraries Government Documents Department
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Operation of the Brookhaven 200 MeV Linac

Description: During the past three years the 200 MeV linear accelerator has continued to operate at a high level of performance and reliability. The linac output beam current has been limited to 60 mA in order to obtain the maximum rf power tube life without compromising the output performance of the AGS. Despite a reduction in pulse repetition rate, total beam current to the BLIP facility has increased to an average of 300 mA hours/year.
Date: January 1, 1979
Creator: Fewell, N.M. & LoDestro, V.
Partner: UNT Libraries Government Documents Department
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Choice of initial operating parameters for high average current linear accelerators

Description: Recent emphasis on alternative energy sources together with the need for intense neutron sources for testing of materials for CTR has resulted in renewed interest in high current (approximately 100 mA) c.w. proton and deuteron linear accelerators. In desinging an accelerator for such high currents, it is evident that beam losses in the machine must be minimized, which implies well matched beams, and that adequate acceptance under severe space charge conditions must be met. An investigation is p… more
Date: January 1, 1976
Creator: Batchelor, K
Partner: UNT Libraries Government Documents Department
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Beam Effects from an Increase of LINAC Current from 40 ma to 49 Milliamperes

Description: On March 25, 2002 the FNAL Linac had been running at a decreased 40 ma of beam current for some time. Both the 400 MeV Linac and the 8GeV Booster had been tuned to optimum running during that time. Optimum running for the Booster was at 4.1e12 per pulse. Losses at injection and at transition were limiting intensity at the time. By March 26, 2002 the Linac beam current had been increased to 49 ma. The optimum Booster intensity immediately jumped to 4.5e12 per pulse and increased in the next few … more
Date: June 5, 2002
Creator: Tomlin, Ray
Partner: UNT Libraries Government Documents Department
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Current enhancement update

Description: Net current enhancement to levels in excess of the beam current has been observed in gases at pressures excess of 50 torr. We delineate the regimes where enhancement is observed. The experimental results fall into two very distinct classes; current enhancement at injection where the beam is only slightly displaced and current enhancement clearly associated with the high amplitude hose instability. A careful theoretical and experimental study of the diagnostics revealed no fundamental flaws alth… more
Date: June 14, 1984
Creator: Chambers, F. W.; Clark, J. C.; Struve, K. W. & Yu, S. S.
Partner: UNT Libraries Government Documents Department
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Development of high current and high brightness negative hydrogen ion sources

Description: Negative hydrogen ions have found important applications in particle accelerators and in fusion research. These ions can be generated from two different types of ion sources---the surface conversion source and the volume production source. Recent experiments demonstrate that H/sup /minus// current exceeding 1 A can be obtained from both types of ion sources. Because of the lower H/sup /minus// ion temperature and the fact that they can be operated without cesium, volume H/sup /minus// sources a… more
Date: April 1, 1988
Creator: Leung, K. N.
Partner: UNT Libraries Government Documents Department
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Final Focus Spot Size in a Solenoid Focusing System

Description: A linear lens can focus a cold beam to a singular point. Unfortunately, this ideal situation would never occur in the real world. Besides nonlinearity of the lens, any deviation of the beam parameters from the ideal beam's nominal beam parameters would lead to nonzero final spot size. In other words, the final spot size of a beam focused by a focusing lens with a given focusing strength depends on its beam parameters, such as the emittance, variations in beam current, energy, envelope and envel… more
Date: April 8, 2003
Creator: Chen, Y. J.
Partner: UNT Libraries Government Documents Department
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Cumulative Beam Breakup with Random Displacement of Cavities and Focusing Elements

Description: We have recently developed an analytical formalism for cumulative beam breakup in linear accelerators with arbitrary beam current profile. The same formalism could be used to investigate the beam breakup-enhanced displacement due to the misalignment of the cavities and the focusing elements. In this paper this analytical formalism is extended and applied to investigate the behavior of beams in misaligned pulsed and cw linear accelerators.
Date: August 1, 2002
Creator: Delayen, Jean
Partner: UNT Libraries Government Documents Department
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Instabilities in the SNS.

Description: The 2MW Spallation Neutron Source (SNS) will have a D.C. beam current of 40 A at extraction, making it one of the worlds most intense accelerators. Coherent instabilities are a major concern and efforts to predict beam behavior are described.
Date: March 29, 1999
Creator: Blaskiewicz, M.
Partner: UNT Libraries Government Documents Department
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Phase and synchronous detector theory as applied to beam position and intensity measurements

Description: A popular signal processing technique for beam position measurements uses the principle of amplitude-to-phase (AM/PM) conversion and phase detection. This technique processes position-sensitive beam-image-current probe-signals into output signals that are proportional to the beam`s position. These same probe signals may be summed and processed in a different fashion to provide output signals that are proportional to the peak beam current which is typically referred to as beam intensity. This pa… more
Date: May 1, 1995
Creator: Gilpatrick, J.D.
Partner: UNT Libraries Government Documents Department
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Intensity Limitations in Fermilab Main Injector

Description: The design beam intensity of the FNAL Main Injector (MI) is 3 x 10{sup 13} ppp. This paper investigates possible limitations in the intensity upgrade. These include the space charge, transition crossing, microwave instability, coupled bunch instability, resistive wall, beam loading (static and transient), rf power, aperture (physical and dynamic), coalescing, particle losses and radiation shielding, etc. It seems that to increase the intensity by a factor of two from the design value is straigh… more
Date: June 1, 1997
Creator: Chan, W.
Partner: UNT Libraries Government Documents Department
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rf quadrupole linac: a new low-energy accelerator

Description: A new concept in low-energy particle accelerators, the radio-frequency quadrupole (RFQ) linac, is currently being developed at the Los Alamos National Scientific Laboratory. In this new linear accelerating structure both the focusing and accelerating forces are produced by the rf fields. It can accept a high-current, low-velocity dc ion beam and bunch it with a high capture efficiency. The performance of this structure as a low-energy linear accelerator has been verified with the successful con… more
Date: January 1, 1980
Creator: Hamm, R. W.; Crandall, K. R. & Fuller, C. W.
Partner: UNT Libraries Government Documents Department
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Simulation of power flow in magnetically insulated convolutes for pulsed modular accelerators

Description: Two distinct simulation approaches for magnetic insulation are developed which can be used to address the question of nonsimultaneity. First, a two-dimensional model for a two-module system is simulated using a fully electromagnetic, two-dimensional, time-dependent particle code. Next, a nonlinear equivalent circuit approach is used to compare with the direct simulation for the two module case. The latter approach is then extended to a more interesting three-dimensional geometry with several MI… more
Date: January 1, 1980
Creator: Seidel, D. B.; Goplen, B. C. & VanDevender, J. P.
Partner: UNT Libraries Government Documents Department
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Beam profile analysis for the C{ampersand}MS B231 electron beam welding machines

Description: The electron beams produced by two different welders were examined using computer assisted tomographic (CT) analysis. The machines used are Hamilton Standard welders with 150 kV/50mA maximum. One machine uses a ribbon filament while the other uses a hairpin filament. The objective of this study was to characterize the beam power distribution on each machine to see if weld parameters could easily be transferred between machines. Beam focus, voltage, and current settings were pre-selected to dupl… more
Date: June 12, 1997
Creator: Elmer, J. W.; Teruya, A.T. & Gauthier, M.
Partner: UNT Libraries Government Documents Department
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Argonne inverted sputter source

Description: The emittance of the inverted sputter source with immersion lenses was measured to be about 5..pi.. mm mrad MeV/sup 1/2/ at the 75% level over a wide range of beam intensities. The use of the source in experiments with radioactive sputter targets and hydrogen loaded targets is described. Self contamination of the source is discussed.
Date: January 1, 1983
Creator: Yntema, J. L. & Billquist, P. J.
Partner: UNT Libraries Government Documents Department
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Multipurpose 5-MeV linear induction accelerator

Description: Although linear induction accelerators (LIAs) are quite reliable by most standards, they are limited in repeating rate, average power, and reliability because the final stage of energy delivery is based on spark gap performance. In addition, they have a low duty factor of operation. To provide a higher burst rate and greater reliability, the researchers used new technology to develop a magnetic pulse compression scheme that eliminates all spark gaps and exceeds requirements. The paper describes… more
Date: June 11, 1984
Creator: Birx, D.L.; Hawkins, S.A.; Poor, S.E. & Reginato, L.L. Smith, M.W.
Partner: UNT Libraries Government Documents Department
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Accelerator power concepts using iolated transmission lines

Description: The rationale and the advantages of using multiple transmission-line sections isolated by transit time and inductance in accelerating high-current (approx. = 10 kA), short-pulse (less than or equal to 100 ns) particle beams to the multimegavolt level is outlined. The main advantages of this system include reducing the number of output switches required per output pulse by nearly an order of magnitude over conventional systems and increasing the system capability for repetition-rate operation. T… more
Date: January 1, 1981
Creator: Nunnally, W.C.
Partner: UNT Libraries Government Documents Department
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Tenth LAMPF users meeting, November 7--9, 1976

Description: The text of a brief talk given before the Tenth LAMPF Users Meeting is presented. Progress made at the Clinton P. Anderson Meson Physics Facility is reported, and the schedule for current upgrading and typical operating cost increases are given.
Date: March 1, 1977
Creator: Rosen, L.
Partner: UNT Libraries Government Documents Department
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Pulsed power for particle beam accelerators in military applications

Description: Techniques useful for generating and conditioning power for high energy pulsed accelerators with potential weapon applications are described. Pulsed electron accelerators are exemplified by ETA and ATA at Lawrence Livermore Laboratories and RADLAC at Sandia Laboratories Albuquerque. Pulse-power techniques used in other applications are briefly mentioned, including some that may be useful for collective ion accelerators. The limitations of pulse-power and the general directions of desirable deve… more
Date: June 20, 1980
Creator: Smith, Ian D.
Partner: UNT Libraries Government Documents Department
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Brightness Limitations in Multi-Kiloampere Electron Beam Sources

Description: Heuristic relationships such as the Lawson-Penner criterion, used to scale Free Electron Laser (FEL) amplifier gain and efficiency over orders of magnitude in beam current and brightness, have no fundamental basis. The brightness of a given source is set by practical design choices such as peak voltage, cathode type, gun electrode geometry, and focusing field topology. The design of low emittance, high current electron guns has received considerable attention at Livermore over the past few year… more
Date: August 24, 1984
Creator: Barletta, W. A.; Boyd, J. K.; Paul, A. C. & Prono, D. S.
Partner: UNT Libraries Government Documents Department
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