2,072 Matching Results

Search Results

Results: 1 - 24 next
open access

Polarization in three-nucleon breakup: experiment and theory

Description: A variety of analyzing powers for d+p breakup reactions initiated by polarized deuterons incident on protons have been measured at deuteron bombarding energies of 16 and 79 MeV. The results are compared with Faddeev calculations using both separable (at 16 and 79 MeV) and local (at 79 MeV) interactions. These calculations include nucleon-nucleon forces in the S, P, and D states and the /sup 3/S/sub 1/-/sup 3/D/sub 1/ tensor force. 19 references.
Date: January 1, 1984
Creator: Brown, R. E.; Hardekopf, R. A.; Jarmie, N.; Correll, F. D.; Lambert, J. M.; Treado, P. A. et al.
Partner: UNT Libraries Government Documents Department
open access

Hydrogen vibrational population distributions and negative ion generation in tandem high density hydrogen discharges

Description: The tandem high-density hydrogen negative-ion-source system is optimized to identify the largest possible ion concentrations and extracted ion currents. The optimization includes varying the length of the second chamber, varying neutral gas and electron densities, and varying the ratio of atomic to molecular density. Vibrational excitation occurs via high-energy electron excitation (E-V process) and H/sub 2//sup +/ surface neutralization (s-V process). These processes are considered separately … more
Date: October 1, 1984
Creator: Hiskes, J. R.; Karo, A. M. & Willmann, P. A.
Partner: UNT Libraries Government Documents Department
open access

Conversion of the BNL 200 MeV Linac to H/sup -/ and polarized H/sup -/ acceleration

Description: Planning for the conversion of the AGS Linac to H/sup -/ acceleration was begun in 1979; installation was completed in 1983. Discussion of this work and of the operational experience will be presented. The AGS Polarized Beam Project was begun in 1980. The design of the new H/sup -/ polarized source, the low Energy Beam Transport line (LEBT), and Radio-Frequency Quadrupole (RFQ) will be described. Current status and future plans will be presented. 14 references, 5 figures.
Date: January 1, 1984
Creator: Witkover, R.L.; Alessi, J.; Barton, D.; Kponou, A.; Makdisi, Y. & McNerney, A.
Partner: UNT Libraries Government Documents Department
open access

RFQ development at Los Alamos

Description: 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.
Partner: UNT Libraries Government Documents Department
open access

Status of the new high intensity H/sup -/ injector at LAMPF

Description: The requirement for higher intensity H/sup -/ ion beams for the proton storage ring now being constructed at LAMPF necessitated the development of a new H/sup -/ ion source and the rebuilding of the original H/sup -/ injector and its associated beam transport lines. The goal of the ion source development program was to produce an H/sup -/ beam with a peak intensity of 20 mA at 10% duty factor and with a beam emittance of less than 0.08 cm-mrad normalized at 95% beam fraction. The ion source con… more
Date: April 1, 1984
Creator: Stevens, R. R. Jr.; York, R. L.; McConnell, J. R. & Kandarian, R.
Partner: UNT Libraries Government Documents Department
open access

Defense terrestrial reactor program

Description: The Defense Terrestrial Reactor (DTR) Program has as its goal the design, construction, and operation of a compact, inherently safe, prototype 10 megawatt-electric (MWe) nuclear reactor. This standarized design could then be deployed to provide a secure energy supply for mission critical functions at selected military installations. This paper outlines the background for selecting nuclear reactors for this application, including military power requirements and an assessment of energy supply alt… more
Date: January 1, 1984
Creator: Kirchner, W. L. & Colston, B. W.
Partner: UNT Libraries Government Documents Department
open access

Parity nonconservation in proton-proton and proton-water scattering at 1. 5 GeV/c

Description: Experiments searching for parity nonconservation in the scattering of 1.5 GeV/c (800 MeV) polarized protons from an unpolarized water target and a liquid hydrogen target are described. The intensity of the incident proton beam was measured upstream and downstream of the target by a pair of ionization detectors. The beam helicity was reversed at a 30-Hz rate. Auxiliary detectors monitored beam properties that could give rise to false effects. The result for the longitudinal asymmetry from the wa… more
Date: July 1, 1984
Creator: Mischke, R. E.; Bowman, J. D.; Carlini, R.; MacArthur, D.; Nagle, D. E.; Frauenfelder, H. et al.
Partner: UNT Libraries Government Documents Department
open access

Absolute dipole gamma-ray strength functions for /sup 176/Lu

Description: We have derived absolute dipole strength-function information for /sup 176/Lu from an average resonance capture study of /sup 175/Lu with 2-keV neutrons, and from neutron capture cross-section measurements with neutrons from 30 keV to about 1 MeV. We found that we needed to increase our previous estimate of the relative M1/E1 strengths near 5 MeV by a factor of 3, and to revise downward the absolute magnitude of our E1 strength function. We accomplished the latter, while still maintaining conti… more
Date: August 29, 1984
Creator: Gardner, D. G.; Gardner, M. A. & Hoff, R. W.
Partner: UNT Libraries Government Documents Department
open access

Practical aspects of tuning a ringed RFQ

Description: A radio-frequency quadrupole (RFQ) constructed at Los Alamos for high-current H/sup -/ operation at 425 MHz and 2.0-MeV output energy has been retrofitted with vane coupling rings (VCRS) introduced at Berkeley. The initial set of seven complete VCR pairs produced excessive operating frequency change, and an arrangement of alternating horizontal and vertical coupling rings eventually was adopted. Because of the periodicity and length of the system, end effects were pronounced. A new type of end … more
Date: April 1, 1984
Creator: Purser, F. O.; Potter, J. M. & Humphry, F. J.
Partner: UNT Libraries Government Documents Department
open access

25. mu. A pulsed polarized H/sup -/ ion source

Description: A Haeberli-type pulsed polarized negative hydrogen source has been brought into operation at the BNL Alternating Gradient Synchrotron. It operates reliably at beam currents sometimes as high as 25 ..mu..A and 20 keV in beam pulses of 500 ..mu..sec with approximately 75% polarization. These beam intensities are about an order of magnitude higher than the original Haeberli source built at the University of Wisconsin. This improvement is caused by the higher densities of both the atomic hydrogen b… more
Date: January 1, 1984
Creator: Alessi, J.; Kponou, A. & Sluyters, T.
Partner: UNT Libraries Government Documents Department
open access

Design, fabrication, and testing of the BNL radio frequency quadrupole accelerator

Description: The Brookhaven National Laboratory polarized H/sup -/ injection program for the AGS utilizes a Radio Frequency Quadrupole Accelerator for acceleration between the polarized source and the Alvarez Linac. Although operation has commenced with a few ..mu.. amperes of H/sup -/ beam, it is anticipated that future polarized H/sup -/ sources will have a considerably improved output. The RFQ will operate at 201.25 MHz and will be capable of handling a beam current of 0.02 amperes with a duty cycle of 0… more
Date: January 1, 1984
Creator: Brown, H.; Clifford, T.; Giordano, S.; Khiari, F.; McKenzie-Wilson, R.; Puglisi, M. et al.
Partner: UNT Libraries Government Documents Department
open access

Contribution of fuel vibrations to ex-core neutron noise during the first and second fuel cycles of the Sequoyah-1 pressurized water reactor

Description: Noise measurements were performed during the first and second fuel cycles of the Sequoyah-1 pressurized water reactor (PWR) to observe long-term changes in the ex-core neutron signatures. Increases in the ex-core neutron noise amplitude were observed throughout the 0.1- to 50.0-Hz range. In-core noise measurements indicate that fuel assembly vibrations contribute significantly to the ex-core neutron noise at nearly all frequencies in this range, probably due to mechanical or acoustic coupling w… more
Date: January 1, 1984
Creator: Sweeney, F. J.; March-Leuba, J. & Smith, C. M.
Partner: UNT Libraries Government Documents Department
open access

Recent progress and developments in LWR-PV calculational methodology

Description: New and improved techniques for calculating beltline surveillance activities and pressure vessel fluences with reduced uncertainties have recently been developed. These techniques involve the combining of monitored in-core power data with diffusion theory calculated pin-by-pin data to yield absolute source distributions in R-THETA and R-Z geometries suitable for discrete ordinate transport calculations. Effects of finite core height, whenever necessary, can be considered by the use of a three-d… more
Date: January 1, 1984
Creator: Maerker, R.E.; Broadhead, B.L. & Williams, M.L.
Partner: UNT Libraries Government Documents Department
open access

Development of a high current H/sup -/ injector for the proton storage ring at LAMPF

Description: A new high-current H/sup -/ injector has been installed at LAMPF for the Proton Storage Ring. The injector is equipped with a multicusp surface-production H/sup -/ ion source that was developed at LAMPF. The ion source is capable of long-term operation at 20 mA of H/sup -/ current at 10% duty factor and with normalized beam emittance of 0.08 cm-mrad (95% beam fraction). Details of the development program, the injector design, and initial operating experience are discussed. Included in the discu… more
Date: January 1, 1984
Creator: York, R. L.; Stevens, Ralph R., Jr.; DeHaven, R. A.; McConnell, J. R.; Chamberlin, E. P. & Kandarian, R.
Partner: UNT Libraries Government Documents Department
open access

Influence of fuel vibration on PWR neutron noise associated with core barrel motion

Description: Ex-core neutron detector noise has been utilized to monitor core support barrel (CSB) vibrations. In order to observe long-term changes, noise signals at Sequoyah-1 were monitored continuously during the whole first fuel cycle and part of the second cycle. Results suggest that neutron noise measurements performed infrequently may not provide adequate surveillance of the CSB because it may be difficult to separate noise amplitude changes due solely to CSB motion from changes caused by fuel motio… more
Date: January 1, 1984
Creator: Sweeney, F. J. & March-Leuba, J.
Partner: UNT Libraries Government Documents Department
open access

Negative ion formation due to hydrogen plasma surface interaction

Description: Negative ions can be produced by a desorption process when energetic positive hydrogen ions impinge on the surface of reactor walls. The relative yield of different negative ions generated from various surface materials (such as Mo, Pt, Pd, Rh, Cu, Ta, Au, C, TiC and stainless-steel) have been compared in a multicusp plasma source. The negative ions generated are self-extracted from the source, and are identified by a mass spectrometer. The total negative ion current is measured by a Faraday cu… more
Date: May 1, 1984
Creator: Leung, K. N. & Ehlers, K. W.
Partner: UNT Libraries Government Documents Department
open access

Boiler Performance and Liquid Entrainment in a Pilot Geothermal Power Plant

Description: Two kettle boilers used in a pilot scale version of a binary geothermal power plant were tested over the life of the project. The results of that testing are presented here. In addition to the overall performance of the boilers, the problem of excessive liquid being entrained in the outlet flow was investigated. Although predictions during the design phase indicated that there would be no significant amount of liquid in the outlet vapor flow, large amounts of liquid were detected when the boile… more
Date: January 1, 1984
Creator: Bliem, Carl J., Jr.
Partner: UNT Libraries Government Documents Department
open access

Hydrogen vibrational population distributions and negative ion generation in tandem high-density hydrogen discharges

Description: The tandem high-density hydrogen negative-ion-source system is optimized to identify the largest possible ion concentrations and extracted ion currents. The optimization includes varying the length of the second chamber, varying neutral gas and electron densities, and varying the ratio of atomic to molecular density. Vibrational excitation occurs via high-energy electron excitation (E-V process) and H/sub 2//sup +/ surface neutralization (s-V process). These processes are considered separately … more
Date: December 3, 1984
Creator: Hiskes, J. R.; Karo, A. M. & Willmann, P. A.
Partner: UNT Libraries Government Documents Department
open access

In-core coolant flow monitoring of pressurized water reactors using temperature and neutron noise

Description: Noise measurements were performed at the Loss-of-Fluid-Test (LOFT) and Sequoyah-1 pressurized water reactors (PWRs) in order to investigate the possibility of inferring in-core coolant velocities from cross-power spectral density (CPSD) phases of core-exit thermocouple and in-core neutron detector signals. These noise measurements were used to investigate the effects of inlet coolant temperature, core flow, reactor power, and random heat transfer fluctuations on the noise-inferred coolant veloc… more
Date: January 1, 1984
Creator: Sweeney, F. J.; Upadhyaya, B. R. & Shieh, D. J.
Partner: UNT Libraries Government Documents Department
open access

Unitary, unified models for NN. -->. NN. pi

Description: First-generation unitary, unified models reproduce the new NN ..-->.. NN..pi.. data reasonably well, but there are two interesting warts in the comparison of theory and experiment. 20 references.
Date: January 1, 1984
Creator: Silbar, R. R.
Partner: UNT Libraries Government Documents Department
open access

Long-term automated surveillance of a commercial nuclear power plant

Description: A pattern recognition system for monitoring nuclear reactor signals is presented. The system is based on detecting deviations from baseline signatures learned automatically during normal plant operation. The capabilities and limitations of the recognition approach were investigated during a 2-1/2-year continuous, on-line series of experiments at the Sequoyah-1 nuclear power plant.
Date: January 1, 1984
Creator: Smith, C.M. & Gonzalez, R.C.
Partner: UNT Libraries Government Documents Department
open access

PWR plant transient analyses using TRAC-PF1

Description: This paper describes some of the pressurized water reactor (PWR) transient analyses performed at Los Alamos for the US Nuclear Regulatory Commission using the Transient Reactor Analysis Code (TRAC-PF1). Many of the transient analyses performed directly address current PWR safety issues. Included in this paper are examples of two safety issues addressed by TRAC-PF1. These examples are pressurized thermal shock (PTS) and feed-and-bleed cooling for Oconee-1. The calculations performed were plant s… more
Date: January 1, 1984
Creator: Ireland, J. R. & Boyack, B. E.
Partner: UNT Libraries Government Documents Department
open access

Theoretical aspects of the nucleon-nucleon workshop

Description: This report concentrates on the inelastic NN system from 300 to 1500 MeV. Topics covered include the visibility of quark signals, dibaryons, the model dependence of predicted NN inelasticities, and a review of how well present conventional models compare with a rapidly expanding database. The general conclusion is that there is so far no clear evidence in the NN system at intermediate energies for unconventional dibaryon resonances. Short remarks are also made concerning one theoretical contrib… more
Date: January 1, 1984
Creator: Silbar, R.R.
Partner: UNT Libraries Government Documents Department
open access

RELAP5/MOD2 Overview and Developmental Assessment Results From TMI-1 Plant Transient Analysis

Description: RELAP5/MOD2 is a new version of the RELAP5 thermal-hydraulic computer code containing improved modeling features that provide a generic capability for pressurized water reactor transient simulation. Objective of this paper is to provide code users with an overview of the code and to report developmental assessment results obtained from a Three Mile Island Unit One plant transient analysis. The assessment shows that the injection of highly subcooled water into a high-pressure primary coolant sys… more
Date: January 1, 1984
Creator: Lin, J. C.; Tsai, C. C.; Ransom, V. H. & Johnsen, G. W.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen