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in creator/contributor: "Jameson, R. A."

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RFQ development at Los Alamos

We report recent progress on the two radio-frequency quadrupole (RFQ) structures being developed at Los Alamos. First, we report on the second 425-MHz RFQ for H/sup -/ acceleration, which is being built in a research effort to understand and further develop the RFQ. Second, we discuss progress on the 80-MHz cw RFQ for deuterons, which is being built for the Fusion Materials Irradiation Test (FMIT) facility.

Date: January 1, 1984

Creator: Armstrong, D. D.; Cornelius, W. D.; Purser, F. O.; Jameson, R. A. & Wangler, T. P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Accelerator technology for Los Alamos nuclear-waste-transmutation and energy-production concepts

Powerful proton linacs are being studied at Los Alamos as drivers for high-flux neutron sources that can transmute long-lived fission products and actinides in defense nuclear waste, and also as drivers of advanced fission-energy systems that could generate electric power with no long-term waste legacy. A transmuter fed by an 800-MeV, 140-mA cw conventional copper linac could destroy the accumulated {sup 99}Tc and {sup 129}I at the DOE's Hanford site within 30 years. A high-efficiency 1200-MeV,… more

Date: January 1, 1991

Creator: Lawrence, G. P.; Jameson, R. A. & Schriber, S. O.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Possible lower limit to licac emittance

Numerical calculations made by several groups have always shown that an asymptotic lower exit emittance exists for linacs operating with high beam current as the input emittance is reduced to zero. In this paper, a mechanism for this limit is shown to be spread in the betatron frequencies of the individual particles due to the combination of space charge and rf gap forces, causing different transverse trajectories correlated with the instaneous longitudinal position of the particle. These traje… more

Date: March 1, 1979

Creator: Staples, J. W. & Jameson, R. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Beam tomography in two and four dimensions. [100 MeV H/sup +/ beams and 750 keV H/sup -/ beams]

The coming generations of high beam-power accelerators require new techniques to monitor the emittance and the shape of the beam; in particular, measurements that do not interfere with the beam itself are necessary. A new computational algorithm, MENT (Maximum ENTropy), will be presented that combines nondestructive profile measurements taken from a number of stations along the beam line with beam-dynamics calculations to compute a four-dimensional phase-space distribution. A version of MENT ha… more

Date: January 1, 1979

Creator: Sander, O. R.; Minerbo, G. N.; Jameson, R. A. & Chamberlin, D. D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Recent improvements in beam diagnostic instrumentation

In high-current machines, such as LAMPF and the envisioned Hanford Engineering Development Laboratory (HEDL) Fusion Materials Irradiation Test (FMIT) Facility linac, hands-on maintenance is desired Beam spill must be kept extremely low; therefore, attention must be given to beam fringes (tails). Beam matching to the structure becomes increasingly important. Equipment capable of accurately measuring transverse beam profiles over a range spanning more than four orders of magnitude and longitudina… more

Date: January 1, 1979

Creator: Sander, O. R.; Jameson, R. A. & Patton, R. D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Report of the heavy-ion fusion task group

An assessment of heavy-ion fusion has been completed. Energetic heavy ions, for example 10-GeV uranium, provided by an rf linac or an induction linac, are used as alternatives to laser light to drive inertial confinement fusion pellets. The assessment has covered accelerator technology, transport of heavy-ion beams, target interaction physics, civilian power issues, and military applications. It is concluded that particle accelerators promise to be efficient pellet drivers, but that there are f… more

Date: February 1, 1980

Creator: Sawyer, G. A.; Booth, L. A.; Henderson, D. B.; Jameson, R. A.; Kindel, J. M.; Knapp, E. A. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

High-brightness rf linear accelerators

The issue of high brightness and its ramifications in linacs driven by radio-frequency fields is discussed. A history of the RF linacs is reviewed briefly. Some current applications are then examined that are driving progress in RF linacs. The physics affecting the brightness of RF linacs is then discussed, followed by the economic feasibility of higher brightness machines. (LEW)

Date: January 1, 1986

Creator: Jameson, R. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Four-dimensional beam tomography

A computer code has been developed to reconstruct the 4-D transverse phase-space distribution of an accelerator beam from a set of linear profiles measured at different angles at three or more stations along the beam line. The code was applied to wire-scan data obtained on the low-intensity H/sup -/ beam of the LAMPF accelerator. A 4-D reconstruction was obtained from 10 wire-scan profiles; 2-D projections of the reconstruction agree fairly well with slit-and-collector measurements of the horiz… more

Date: January 1, 1981

Creator: Minerbo, G. N.; Sander, O. R. & Jameson, R. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Design for low beam loss in accelerators for intense neutron source applications

Control of beam loss in intense ion linacs involves keeping beam spill below parts in 10[sup [minus]5]--10[sup [minus]8]/m by preventing total beam size from extending to the limiting apertures. Starting from good rms design practices, new analysis of the machine architecture is described in terms of the effects of the machine tune with space-charge, free-energy constraint, and halo-producing mechanisms. It is shown that halos are produced by the time- (or position-) varying nature of common li… more

Date: January 1, 1993

Creator: Jameson, R. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

A new approach to modeling linear accelerator systems

A novel computer code is being developed to generate system level designs of radiofrequency ion accelerators with specific applications to machines of interest to Accelerator Driven Transmutation Technologies (ADTT). The goal of the Accelerator System Model (ASM) code is to create a modeling and analysis tool that is easy to use, automates many of the initial design calculations, supports trade studies used in accessing alternate designs and yet is flexible enough to incorporate new technology … more

Date: July 22, 1994

Creator: Gillespie, G. H.; Hill, B. W. & Jameson, R. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Design for low beam loss in accelerators for intense neutron source applications

Control of beam loss in intense ion linacs involves keeping beam spill below parts in 10{sup {minus}5}--10{sup {minus}8}/m by preventing total beam size from extending to the limiting apertures. Starting from good rms design practices, new analysis of the machine architecture is described in terms of the effects of the machine tune with space-charge, free-energy constraint, and halo-producing mechanisms. It is shown that halos are produced by the time- (or position-) varying nature of common li… more

Date: June 1, 1993

Creator: Jameson, R. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

A new tool for accelerator system modeling and analysis

A novel computer code is being developed to generate system level designs of radiofrequency ion accelerators. The goal of the Accelerator System Model (ASM) code is to create a modeling and analysis tool that is easy to use, automates many of the initial design calculations, supports trade studies used in assessing alternate designs and yet is flexible enough to incorporate new technology concepts as they emerge. Hardware engineering parameters and beam dynamics are modeled at comparable levels… more

Date: September 1, 1994

Creator: Gillespie, G. H.; Hill, B. W. & Jameson, R. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Energy variable deuteron linac for materials research neutron source

Basic research in new materials and materials technology is a key national resource, and several countries are making plans for advanced capabilities, including intense neutron sources. Advances in high-intensity linear accelerator technology can provide efficient drivers for such sources. Aspects such as energy variability, uniformity of target dose distribution, target bombardment from multiple directions, time-scheduled dose patterns, and other features can be provided, opening new opportuni… more

Date: January 1, 1990

Creator: Jameson, R. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Self-consistent beam halo studies & halo diagnostic development in a continuous linear focusing channel

Beam halos are formed via self-consistent motion of the beam particles. Interactions of single particles with time-varying density distributions of other particles are a major source of halo. Aspects of these interactions are studied for an initially equilibrium distribution in a radial, linear, continuous focusing system. When there is a mismatch, it is shown that in the self-consistent system, there is a threshold in space-charge and mismatch, above which a halo is formed that extends to {app… more

Date: December 1, 1994

Creator: Jameson, R. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Linear accelerator modeling: development and application. [PARMILA]

Most of the parameters of a modern linear accelerator can be selected by simulating the desired machine characteristics in a computer code and observing how the parameters affect the beam dynamics. The code PARMILA is used at LAMPF for the low-energy portion of linacs. Collections of particles can be traced with a free choice of input distributions in six-dimensional phase space. Random errors are often included in order to study the tolerances which should be imposed during manufacture or in o… more

Date: January 1, 1977

Creator: Jameson, R. A. & Jule, W. D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Accelerator Technology Program: Status report, October 1985--March 1986: Volume 1

This report presents highlights of the major projects in the Accelerator Technology (AT) Division of the Los Alamos National Laboratory. The first section details progress associated with the accelerator test stand. Following sections cover achievements in accelerator theory and simulation, LAMPF II accomplishments, and updates on BEAR, beam dynamics, the rf laboratory, p-bar gravity experiment, University of Illinois racetrack microtron, and NBS microtron. Also included are results from the Pr… more

Date: July 1, 1988

Creator: Jameson, R. A. & Schriber, S. O.

Item Type: Report

Partner: UNT Libraries Government Documents Department