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in creator/contributor: "Brown, R. D."

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Power deposition measurements at the LAMPF Neutron Radiation Effects Facility

A calorimeter has been used in the LAMPF A-6 neutron radiation effects area to measure the power deposition about 20 cm from the isotope production targets. The measured value is about 2 w/cm/sup 3//mA, in reasonable agreement with previously calculated values. 3 refs., 3 figs.

Date: June 1, 1985

Creator: Brown, R. D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Mechanical properties of 800-MeV proton-irradiated metals

Accelerator beam line components and spallation neutron targets operate in an irradiation environment where changes in mechanical properties can adversely affect component integrity. The present work presents a preliminary study of the effects of low fluences (10/sup 19/ to 10/sup 20/ p/cm/sup 2/) of 800-MeV protons on the yield strength, tensile strength, and ductility of samples of 304 stainless steel, Alloy 718, molybdenum, and tantalum. Tensile samples (0.75 or 1.6 mm thick) were directly w… more

Date: January 1, 1982

Creator: Brown, R. D. & Cost, J. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Graphite targets at LAMPF

Rotating polycrystalline and stationary pyrolytic graphite target designs for the LAMPF experimental area are described. Examples of finite element calculations of temperatures and stresses are presented. Some results of a metallographic investigation of irradiated pyrolytic graphite target plates are included, together with a brief description of high temperature bearings for the rotating targets.

Date: January 1, 1983

Creator: Brown, R. D. & Grisham, D. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Radiation-induced changes in magnetic properties of Nd-Fe-B permanent magnets

The high remanence and intrinsic coercivity of Nd-Fe-B magnets make them desirable for use in the accelerators. Use in the radiation environment of an accelerator requires that the sensitivity of these magnets to radiation be determined and the mechanisms responsible be understood. We present results comparing the relative radiation sensitivity of a number of commercially available Nd-Fe-B magnets. Small samples of these magnets were irradiated at the Omega West Reactor in a neutron flux of 2 x… more

Date: January 1, 1987

Creator: Brown, R. D. & Cost, J. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Radionuclides in US coals

The current state of knowledge with respect to radionuclide concentrations in US coals is discussed. Emphasis is placed on the levels of uranium in coal (and lignite) which are considered to represent a concern resulting from coal combustion; areas of the US where such levels have been found; and possible origins of high radionuclide levels in coal. The report reviews relevant studies and presents new data derived from a computerized search of radionuclide content in about 4000 coal samples col… more

Date: March 1, 1984

Creator: Bisselle, C. A. & Brown, R. D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

New stringer for the LAMPF radiation effects facility

New stringer design, allowing access to the spallation neutron flux at the Clinton P. Anderson Meson Physics Facility (LAMPF) beam stop is described, together with information on the neutron spectrum.

Date: January 1, 1981

Creator: Brown, R. D. & Hansen, C. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Water-cooled pyrolytic graphite targets at LAMPF: design and operation

Design considerations and actual operating experience are reported for water-cooled pyrolytic graphite targets at the Clinton P. Anderson Meson Physics Facility (LAMPF). Emphasis is placed on the use of finite element computer calculations to determine target temperatures and stresses, which can then be evaluated to judge the usefulness of a particular design. Consideration is also given to the swelling of the target following irradiation, and to the measures taken to prolong target lifetime.

Date: January 1, 1981

Creator: Brown, R. D. & Grisham, D. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

LANSCE target calculations

The LANSCE target operates at a beam current of 30 microamps. We present here the results of the finite-element calculations for the temperatures and stresses in the present target operated at 100 microamps. The calculations were run using the ABAQUS finite-element code. All finite-element codes require as input both the boundary conditions for the material being heated, and such material properties as the thermal conductivity, specific heat, and the elastic modulus. For the LANSCE target, the … more

Date: January 1, 1989

Creator: Grisham, D. L. & Brown, R. D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Health and environmental effects of oil and gas technologies: research needs

This report discusses health and environmental issues associated with oil and gas technologies as they are currently perceived - both those that exist and those that are expected to emerge over the next two decades. The various sections of this report contain discussions of specific problem areas and relevant new research activities which should be pursued. This is not an exhaustive investigation of all problem areas, but the report explores a wide range of issues to provide a comprehensive pic… more

Date: July 1, 1981

Creator: Brown, R. D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Mechanical properties testing of several 800 MeV proton irradiated BCC metals and alloys. [Candidate window materials for SIN beam stop]

A spallation neutron source for the 600-MeV proton accelerator facility at the Swiss Institute for Nuclear Research (SIN) consists of a vertical cylinder filled with molten Pb-Bi. The proton beam enters the cylinder, passing upward through a window in contact with the Pb-Bi eutectic liquid. Investigations are underway at the 800-MeV proton accelerator at LAMPF to test the performance of candidate SIN window materials. Based on considerations of chemical compatibility with molten Pb-Bi, as well … more

Date: January 1, 1986

Creator: Brown, R. D.; Wechsler, M. S. & Tschalaer, C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Remote recovery of irradiated tensile samples incapsulated in Pb-Bi

The Swiss Institute for Nuclear Research (SIN) is upgrading their proton accelerator to 1 to 2 mA Beam current at 600 MeV. Molten Pb-Bi is being considered as a beam stop. The materials in the beam stop must be chemically compatible with molten Pb-Bi, retain ductility and strength, and have a lifetime of at least six months. In a joint venture between the United States and SIN, four capsules were designed and loaded with eight tensile samples. The tensile samples were Ta, Cr (Fe-2 1/4% Cr-1% Mo… more

Date: January 1, 1985

Creator: Nicol, A. G.; Brown, R. D. & Cook, J. H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Beam line windows at LAMPF

The A-6 main beam-line window at LAMPF separates the vacuum of the main beam line from the isotope production station, proton irradiation ports, and the beam stop, which operate in air. This window must withstand the design beam current of 1 mA at 800 MeV for periods of at least 3000 hours without failure. The window is water cooled and must be strong enough to withstand the 2.1 MPa (300 psig) cooling water pressure, as well as beam-induced thermal stresses. Two designs have been used to meet t… more

Date: January 1, 1985

Creator: Brown, R. D.; Grisham, D. L. & Lambert, J. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Irradiation damage in metals produced by 800-MeV protons

Theoretical calculations of damage energies in metals from 800-MeV proton irradiation motivated an experimental transmission electron microscopy study of the damage produced. Damage produced by 800-MeV protons is accompanied by a higher level of helium production than for reactor neutron irradiation. To allow irradiation of samples on a routine basis, a proton irradiation port (PIP) was constructed in beam line A at LAMPF. This port allowed a high damage-rate irradiation of metal foils several … more

Date: July 1, 1979

Creator: Brown, R. D.; Sommer, W. F. & Green, W. V.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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The Mobil Integrated C{sup 3} (command control and communications) and Security System

The current political and economic situations suggest that significant reductions of nuclear forces outside the US will continue. This implies that in times of crisis the rapid deployment of nuclear weapons into a theater may be required. This paper describes a proposed Mobile Integrated C{sup 3} and Security System (MICSS). The MICSS, together with associated personnel, could satisfy the command and control and security requirements of a deployed nuclear operation. Rapid deployment poses uniqu… more

Date: June 15, 1993

Creator: Eras, A. & Brown, R. D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Radiation effects on samarium-cobalt permanent magnets

With the recent advances in rare-earth-cobalt (REC) permanent magnet technology, new applications are being implemented that were previously not feasible. One such application is the use of permanent magnetic lenses for accelerator and beam transport systems. In many of these areas the magnetic transport systems are subjected to high radiation levels. Consequently, there is considerable interest in the United States and abroad in the possible changes in the magnetic field when subjected to radi… more

Date: July 1, 1982

Creator: Brown, R. D.; Bush, E. D. Jr. & Hunter, W. T.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Data qualification for the Waste Isolation Pilot Plant

The Waste Isolation Pilot Plant (WIPP) site near Carlsbad, New Mexico, has been the subject of scientific and engineering investigations for more than twenty years. Data from these investigations are now being used as part of the process to certify compliance of the WIPP with the governing regulations. Some of these data were collected prior to the development and implementation of the quality assurance (QA) standards that are now being applied in the WIPP compliance certification process, and … more

Date: March 1, 1996

Creator: Brown, R. D. & Harper-Slaboszewicz, V. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Neutron irradiation study of Nd-Fe-B permanent magnets made from melt-spun ribbons

Radiation-induced changes in the magnetization of sintered Nd-Fe-B permanent magnets are known to vary widely among specimens produced by different manufacturers. Samples of Nd-Fe-B MAGNEQUENCH magnets, which are made from melt-spun ribbons, have now been studied and show a much reduced sensitivity to neutron irradiation than do sintered Nd-Fe-B magnets. All melt-spun ribbon-based MAGNEQUENCH magnets, i.e., epoxy-bonded, hot-pressed, and die-upset magnets, show essentially the same slow decreas… more

Date: January 1, 1988

Creator: Brown, R. D.; Cost, J. R.; Meisner, G. P. & Brewer, E. G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Defect formation in 800-MeV proton-irradiated aluminum

Transmission electron microscopy was used to investigate the formation of irradiation-induced defects in proton-irradiated high-purity aluminum. The specimens were irradiated by 800-MeV protons to about 0.25 displacements per atom (dpa) in the Los Alamos Meson Physics Facility (LAMPF), producing about 20 atomic ppM helium, 130 atomic ppM hydrogen, and approximately 70 atomic ppM of spallation products. The as-irradiated microstructure mainly consisted of cavities with a mean size of 88 A, numbe… more

Date: November 1, 1979

Creator: Jang, H.; Moteff, J.; Levinson, L.; Brown, R. D. & Green, W. V.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

The development of small-scale quadrupoles to operate at 20 to 50K

The development of cryogenically cooled, high-frequency linacs at Los Alamos necessitates that small quadrupoles be developed to operate inside the drift tubes at temperatures as low as 20 K. A program has been undertaken to procure some of these quads, designed to critical specifications, and to test them for field-gradient and harmonic- distortion changes when taken down to the 20- to 50-K operating range and cycled many times back to room temperature. In this application SmCo/sub 5/ and Sm/s… more

Date: January 1, 1988

Creator: Liska, D. J.; Kraus, R. H.; Brown, R. D. & Cost, J. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Radiation Effects in Rare-Earth Permanent Magnets.

Nd-Fe-B and Sm-Co permanent magnets have been irradiated with fission neutrons and gamma rays. Irradiated samples were periodically removed for room temperature measurements of the open-circuit remanence. Hysteresis loops were measured before and after irradiation. For neutron irradiation, two magnets showed a rapid loss of remanence, while a third decayed more slowly. Irradiation in the Omega West Reactor at Los Alamos with fast neutrons caused the fast-decay samples to have an initial loss of… more

Date: 1987

Creator: Cost, J. R.; Brown, R. D.; Giorgi, A. L. & Stanley, J. T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Rabbit system for foil activation irradiations at the Los Alamos Spallation Radiation Effects Facility at LAMPF

A ''rabbit'' system has been installed in an insert at the Los Alamos Spallation Radiation Effects Facility (LASREF). Spallation neutrons at LASREF are produced by the passage of the LAMPF 800-MeV proton beam through the Isotope Production (IP) targets and into the beam stop. This dosimetry insert allows measurement of the spallation neutron and secondary proton fluxes and energy spectra in any of the 12 neutron irradiation locations. Four ''rabbit'' tubes allow radial measurements at 0.12, 0.1… more

Date: January 1, 1986

Creator: Davidson, D. R.; Brown, R. D.; Taylor, I. K.; Sommer, W. F. & Martinez, L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Radiation damage in YBa/sub 2/Cu/sub 3/O/sub 7/ by fast neutrons

The superconducting transition temperature of sintered YBa/sub 2/Cu/sub 3/O/sub 7/ decreases at a rate of 2.7 K/10/sup 18/ n/cm/sup 2/ (E > 0.1 MeV) for fast neutron irradiation. The critical current density J/sub c/ increases a factor of three at zero field and more than three at nonzero fields for fluences up to 2 x 10/sup 18/ n/cm/sup 2/. At both 7 and 75 K, J/sub c/ is decreasing with fluence near 3 x 10/sup 18/ n/cm/sup 2/.

Date: January 1, 1987

Creator: Willis, J. O.; Cost, J. R.; Brown, R. D.; Thompson, J. D. & Peterson, D. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Progress report on the accelerator production of tritium materials irradiation program

The Accelerator Production of Tritium (APT) project is developing an accelerator and a spoliation neutron source capable of producing tritium through neutron capture on He-3. A high atomic weight target is used to produce neutrons that are then multiplied and moderated in a blanket prior to capture. Materials used in the target and blanket region of an APT facility will be subjected to several different and mixed particle radiation environments; high energy protons (1-2 GeV), protons in the 20 … more

Date: May 1997

Creator: Maloy, S. A.; Sommer, W. F.; Brown, R. D. & Roberts, J. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Experience at the Los Alamos Meson Physics Facility with the use of alloy Inconel 718 as an enclosure for a beam degrader and as a proton beam entry window

Operation of the Los Alamos Meson Physics Facility (LAMPF) began in 1972 and continues at present. An injector delivers protons to a 0.8 kin long linear accelerator which produces a particle energy of 800 MeV; the protons are then transported to a variety of experimental areas. The proton beam is transported in a vacuum tube, controlled and bent by electromagnets. The highest intensity beam, at a maximum level of 1 mA, is delivered to the experimental area designated as Area A. At the end of th… more

Date: September 1, 1994

Creator: Sommer, W. F.; Ferguson, P. D.; Brown, R. D.; Cedillo, C. M. & Zimmerman, E.

Item Type: Article

Partner: UNT Libraries Government Documents Department