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in subjects: "Hydrogen 1 Minus Beams"

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Historical perspective of the H{sup {minus}} Ion Source Symposia

The International Symposium on the Production and Neutralization of Negative Hydrogen Ions and Beams is entering its third decade of providing a forum for the H{sup -} ion source community. The first meeting was held at Brookhaven National Laboratory in 1977 and has returned there every three years to 1995. This is the eighth meeting in this series and for the first time is in Europe, hosted by CEA/Center de Cadarache. Since this Symposium is meeting in Europe many new people have had an opport… more

Date: November 1, 1997

Creator: Schmidt, C.W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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The BNL polarized H{sup {minus}} ion source development program

Polarized protons have been available for acceleration in the AGS for the high energy physics program since 1984. The polarized H{sup {minus}} source, PONI-1, has routinely supplied a 0.4 Hz, 400 {mu}sec pulse having a nominal intensity of 40 {mu}A. Polarization is {approximately}80% out of the ion source. After PONI- 1 became operational, a program was initiated to develop a more intense source based on a cold ground state atomic beam source, followed by ionization of the polarized H{degrees} … more

Date: December 31, 1992

Creator: Kponou, A.; Alessi, J.; Hershcovitch, A. & DeVito, B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Volume H{sup {minus}} ion source development at LAMPF

One method of increasing the intensity of the LAMPF proton Storage Ring is to use a brighter H{sup {minus}} ion source. To develop such a source, the performance of the small LBL dipole filter and the BNL toroidal filter volume H{sup {minus}} sources are being investigated. Results of testing a new high-duty-factor design of the BNL toroidal filter volume source are discussed. Results of experiments to reduce the electron to H{sup {minus}} ratio and modulate the beam intensity in the small LBL … more

Date: June 1, 1993

Creator: York, R. L.; Tupa, D.; Swenson, D. R. & Damjanovich, R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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A feasibility study of beam-chopping at low energy for LANSCE

This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). If a beam-chopping system could be developed for the Los Alamos Meson Physics Facility low-energy beam line, there would be potential to operate the Los Alamos Neutron Scattering Center (LANSCE) at much higher power and duty factor and enable such operation with a radio-frequency quadrapole (RFQ) injector. This would greatly extend the capability of t… more

Date: October 1, 1996

Creator: Wang, Tai-Sen; Channell, P.J. & Mottershead, C.T.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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BNL Volume H{sup {minus}} Sources

An H{sup -} current of up 30 mA has been extracted from a 1 cm{sup 2} aperture in a 20 cm diameter volume source with a conical filter field. From a 9.7 cm diameter version of this source, an H{sup -} current of up to 35 mA was extracted from a 0.5 cm{sup 2} aperture.In both sources, the electron-to-H{sup -} ratio is typically < 10, and often < 5.

Date: December 31, 1992

Creator: Alessi, J. G.; Prelec, K. & McCafferty, D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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1-GeV Linac Upgrade Study at Fermilab

A linac injector for a new proton source complex at Fermilab is assumed to have a kinetic energy of 1 GeV. This linac would be sized to accelerate 100 mA of H{sup -} beam in a 200 microsecond pulse at a 15 Hz repetition rate. This would be adequate to produce {approximately}10{sup 14} protons per pulse allowing for future improvements of the new proton source complex. An alternate proposal is to add 600 MeV of side coupled cavity linac at 805 MHz to the existing 400 MeV Linac. This addition may… more

Date: September 1998

Creator: Popovic, M.; Moretti, A.; Noble, R. & Schmidt, C. W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Laser diagnostic for high current H{sup {minus}} beams

Laser photodetachment can be used on high current, high energy H{sup {minus}} beams to carry out a wide variety of beam diagnostic measurements parasitically during normal operation, without having to operate the facility at either reduced current or duty cycle. Suitable Q-switched laser systems are small, inexpensive, and can be mounted on or near the beamline. Most of the proposed laser-based diagnostics techniques have already been demonstrated.

Date: January 1, 1998

Creator: Shafer, R. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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A new generation of medical cyclotrons for the 90`s

Cyclotrons continue to be efficient accelerators for use in radio-isotope production. In recent years, developments in accelerator technology have greatly increased the practical beam current in these machines while also improving the overall system reliability. These developments combined with the development of new isotopes for medicine and industry, and a retiring of older machines indicates a strong future for commercial cyclotrons. In this paper the authors will survey recent developments … more

Date: August 1, 1995

Creator: Milton, B. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Implications of electron attachment to highly-excited states in pulsed-power discharges

The author points out the possible implications of electron attachment to highly-excited states of molecules in two pulsed power technologies. One involves the pulsed H{sub 2} discharges used for the generation of H ion beams for magnetic fusion energy and particle accelerators. The other is the power modulated plasma discharges used for material processing.

Date: August 1, 1997

Creator: Pinnaduwage, L.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Lessons learned on the Ground Test Accelerator control system

When we initiated the control system design for the Ground Test Accelerator (GTA), we envisioned a system that would be flexible enough to handle the changing requirements of an experimental project. This control system would use a developers` toolkit to reduce the cost and time to develop applications for GTA, and through the use of open standards, the system would accommodate unforeseen requirements as they arose. Furthermore, we would attempt to demonstrate on GTA a level of automation far b… more

Date: September 1, 1994

Creator: Kozubal, A. J. & Weiss, R. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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High-Current Negative-Ion Beam Transport

The requirements for transporting high-current, negative-ion beams are presented with particular emphasis on applications involving negative-hydrogen-ion beams. In addition to the usual matching and steering problems, particular attention must be paid to beam emittance growth in the transport system. Depending on the application, a number of approaches have been developed using both magnetic and electric lenses. I discuss the design considerations for transporting and matching these beams to ra… more

Date: April 1, 1993

Creator: Stevens, Ralph R., Jr.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Initial operation of the CW 8X H{sup {minus}} ion source discharge

A pulsed 8{Chi} source was built and the H{sup {minus}} beam current, emittance, and power efficiency were measured. These results were promising, so a cooled, dc version designed for operation at arc power levels up to 30 kW was built. Testing of the CW 8{Chi} source discharge is underway. The design dc power loading on the cathode surface is 900 W/cm{sup 2}, considerably higher than achieved in any pervious Penning surface-plasma source (SPS). Thus, the electrode surfaces are cooled with pres… more

Date: June 1, 1993

Creator: Smith, H. V. Jr.; Allison, P.; Geisik, C.; Schmitt, D. R.; Schneider, J. D. & Stelzer, J. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Recent operating experience with the H{sup {minus}} ion injector at LAMPF/LANSCE

A cusp-field cesium conversion ion source has provided H{sup -} beams at LAMPF/LANSCE since 1984. three interchangeable sources are now used during beam production cycles to minimize down time during scheduled source change-outs. Ion source change-outs are scheduled to prevent unscheduled loss of beam time due to finite filament lifetime. Ion source operating parameters and filament lifetime data are presented.

Date: September 1, 1996

Creator: Ingalls, W. B.; Stelzer, J. E. & Williams, H. E., III

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Separation of beam and electrons in the spallation neutron source H{sup -} ion source

The Spallation Neutron Source (SNS) requires an ion source producing an H{sup {minus}} beam with a peak current of 35mA at a 6.2 percent duty factor. For the design of this ion source, extracted electrons must be transported and dumped without adversely affecting the H{sup {minus}} beam optics. Two issues are considered: (1) electron containment transport and controlled removal; and (2) first-order H{sup {minus}} beam steering. For electron containment, various magnetic, geometric and electrode… more

Date: December 1, 1997

Creator: Whealton, J. H.; Raridon, R. J. & Leung, K. N.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Pulsed optically-pumped polarized H{sup {minus}} ion source development

Results are presented of pulsed optically-pumped polarized H{sup {minus}} ion source (OPPIS) development for high energy accelerators. An atomic hydrogen beam intensity of 2 {times} 10{sup 18} atoms/s within the polarizer acceptance was obtained with an atomic H injector at BINP. A pulsed polarized H{sup {minus}} ion current of about 10--20 mA should be obtainable using this injector. Limitations on beam characteristics due to space-charge were studied. A polarization scheme to avoid space-char… more

Date: September 1, 1995

Creator: Zelenski, A. N.; Davydenko, V. I.; Dimov, G.I.; Levy, C. D. P.; Oers, W. T. H.; Schmor, P. W. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Final Report to the U.S. DOE Grant DE-FG03-93-ER14326

This document presents an overview of the results of the DOE's support of experimental research into the structure and interactions of the negative ion of hydrogen conducted by the Department of Physics and Astronomy of the University of New Mexico at the Los Alamos National Laboratory. The work involves many collaborations with scientists from both institutions, as well as others. Although official DOE support for this work began in 1977, the experiment that led to it was done in 1971, near th… more

Date: June 30, 1999

Creator: Bryant, Howard C.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Recent development on RF-driven multicusp H{sup {minus}} ion sources

The radio-frequency (rf) driven multicusp source was originally developed for use in the Superconducting Super Collider injector. The source routinely provided 35 keV, 30 mA of beam at 0.1% duty factor. By using a new cesium dispensing system, beam current in excess of 100 mA and e/H{sup -} {approx}1 have been observed. For pulse mode operation, the rf discharge can be started by means of a xenon flash lamp. Extracted electrons in the beam can be efficiently removed by employing a permanent mag… more

Date: June 1, 1996

Creator: Leung, K. N.; De Vries, G. J.; Kunkel, W. B.; Perkins, L. T.; Pickard, D. S.; Saadatmand, K. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Beam dynamics simulations of the LANSCE linac

Detailed beam dynamics calculations of the LANSCE Linac have been performed using multi-particle simulation codes. The LANSCE accelerator produces both H{sup +} and H{sup {minus}} beams and is comprised of Cockcroft-Walton injectors, a 100 MeV drift-tube linac and an 800 MeV side-coupled linac. Several improvements to the simulations of H{sup +} and H{sup {minus}} beams have recently been made. These include the use of more accurate input distributions and a better estimate of beam neutralizati… more

Date: December 31, 1998

Creator: Merrill, F. & Rybarcyk, L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Volume H[sup [minus]] ion source development at LAMPF

One method of increasing the intensity of the LAMPF proton Storage Ring is to use a brighter H[sup [minus]] ion source. To develop such a source, the performance of the small LBL dipole filter and the BNL toroidal filter volume H[sup [minus]] sources are being investigated. Results of testing a new high-duty-factor design of the BNL toroidal filter volume source are discussed. Results of experiments to reduce the electron to H[sup [minus]] ratio and modulate the beam intensity in the small LBL … more

Date: January 1, 1993

Creator: York, R.L.; Tupa, D.; Swenson, D.R. & Damjanovich, R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Commissioning of the First Drift Tube Linac Module in the Ground Test Accelerator

The Ground Test Accelerator (GTA) has the objective of verifying much of the technology required for producing high-brightness, high-current H{sup {minus}} beams. GTA commissioning is staged to verify the beam-dynamics design of each major accelerator component as it is brought on-line. The major components are the 35-keV H{sup {minus}} injector, the 2.5-MeV radio-frequency quadrupole (RFQ), the intertank matching section (IMS), the 3.2 MeV first 2{beta}{lambda} drift tube linac (DTL-1) module,… more

Date: June 1, 1993

Creator: Johnson, K. F.; Sander, O. R.; Atkins, W. H.; Bolme, G. O.; Bowling, S.; Cole, R. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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The BNL volume H sup minus ion source

This paper is a progress report on the studies of the BNL volume H{sup {minus}} ion source. We have measured the H{sup {minus}} yield, I{sub H}{sup {minus}}, and the ratio I{sub e}/I{sub H}{sup {minus}} as function of the size of the extraction aperture, strength of the conical filter field, size and position of the filament, and of the phase of the filament heating current. The H{sup {minus}} current density in the extraction aperture was lower for the largest aperture, while there was a broad… more

Date: January 1, 1989

Creator: Prelec, K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Study of field ionization in the charge exchange injection for the IPNS upgrade

The proposed I-MW neutron spallation source is a rapid-cycling synchrotron (RCS) with a design intensity of 1.04 {times} 10{sup 14} protons. A H- beam from the linac is injected into the synchrotron via the charge exchange process. Due to the high intensity of the beam, the minimization of beam loss is one of the primary concerns. In this paper, we study a possible beam loss associated with field ionization, which includes estimates of the charge fraction and level distribution of the excited h… more

Date: July 1, 1995

Creator: Chase, Yong-Chul, Cho, Yanglai

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Experimental study of a simple method to chop Penning SPS H{sup {minus}} beams

Accumulator rings proposed for use in high-intensity spallation-neutron sources require a chopped beam with particle-free gaps {approx}100 ns wide at 1--2 MHz rates with rise and fall times {le} 20 ns. Chopping the beam directly in the ion source may be an attractive way to provide the desired beam structure. A grounded collar placed in the drift region next to the emission aperture lowers the e{sup {minus}}/H{sup {minus}} ratio in the 8X source H{sup {minus}} beam. We electrically isolated the… more

Date: August 1, 1994

Creator: Smith, H. V. Jr.; Allison, P.; Schneider, J. D. & Stelzer, J. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Implementation of a low energy proton line from the Fermilab Linac

Two beamlines presently transport the H{sup {minus}} beam from the Fermilab Linac. Implementing extraction of some portion of the beam from either line is complicated by the close confines of the enclosure area and the presence of the elements in the existing lines. A new technique has been devised which employs laser stripping of H{sup {minus}} to H{sup 0} in order to extract a third beam using the existing beamline components in their current configuration. The laser approach has the addition… more

Date: July 1, 1992

Creator: Johnstone, C.

Item Type: Report

Partner: UNT Libraries Government Documents Department