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in subjects: "Spallation"

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Nuclear chemistry research of high-energy nuclear reactions at Carnegie-Mellon University, 1961--1977. Summary report. [Summaries of research activities at Carnegie-Mellon University]

The activities and the results of research in the study of high energy nuclear reactions carried out at Carnegie Institute of Technology from 1957 to 1967 and at Carnegie-Mellon University from 1967 to 1977 are summarized. A complete list of all publications, doctoral dissertations, and reports resulting from the research of this project is also included. A major part of the report is a review of the research activities and results. The objective of the research of this project was the study of… more

Date: November 1, 1977

Creator: Caretto, A. A., Jr.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Potential capabilities at LAMPF to study nuclei far from stability

Feasibility studies have shown that a He-jet activity transport line, with a target chamber placed in the LAMPF main beam line, will provide access to short-lived isotopes of a number of elements that cannot be extracted efficiently for study at any other type of on-line facility. The He-jet technique requires targets thin enough to allow a large fraction of the reaction products to recoil out of the target foils; hence, a very intense incident beam current, such as that uniquely available at L… more

Date: January 1, 1985

Creator: Talbert, W. L. & Bunker, M. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Experimental nuclear and radiochemistry. Progress report, February 1, 1979-January 31, 1980. [Dept. of Chemistry, Carnegie-Mellon Univ. , Pittsburgh, Pennsylvania, 2/1/79 to 1/31/80]

This project entails the investigation of deep nuclear spallation reactions induced by high-energy light particles on complex nuclei. Experimental studies involve activation of various medium- to heavy-mass targets bombarded by pi mesons, protons, and alpha particles. A prime objective is to deconvolve the cascade and evaporation steps in the reaction mechanism. Experimentally, then, particular emphasis has been placed on spallation products far from yield maxima. Irradiations have been perform… more

Date: January 1, 1980

Creator: Karol, P. J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Spallation target-moderator-reflector studies at the Weapons Neutron Research facility. [800-MeV p]

Basic neutronics data, initiated by 800-MeV proton spallation reactions, are important to spallation neutron source development and electronuclear fuel production. Angle-dependent and energy-dependent neutron production cross sections, energy-dependent and total neutron yields, thermal and epithermal neutron surface and beam fluxes, and fertile-to-fissile conversion ratios are being measured. The measurements are being done at the Weapons Neutron Research facility on a variety of targets and ta… more

Date: January 1, 1980

Creator: Russell, G. J.; Gilmore, J. S.; Prael, S. D.; Robinson, H. & Howe, S. D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Nuclear research with heavy ions. Annual progress report, January 1, 1977--December 31, 1977

The experimental research program consists of several interrelated parts: (1) Reactions of Very Heavy Ions with Complex Nuclei; (2) Studies of Compound Nucleus Reactions Induced by Heavy Ions; and (3) Recoil Studies of Heavy Ion Reactions. Using solid-state detector telescopes and gas-ionization detector telescopes we have studied the emission of /sup 1/H, /sup 2/H, /sup 3/H, /sup 4/He and heavy fragments from the reactions of 720 MeV /sup 86/Kr with /sup 197/Au. Coincidence measurements betwee… more

Date: October 1, 1977

Creator: Kaplan, Morton

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Linear accelerator fission product transmuter (LAFPT)

The use of a Linear Accelerator Fission Product Transmuter (LAFPT) for the purpose of reducing the quantity of long-lived fission products (LLFP's) waste including transuranic waste (TU's) by means of spallation and neutron reactions, converting the LLFP's to shorter-lived isotopes or to stable type material, is considered. The linear accelerator offers proton energies in the range of 0.5 to 1.5 GeV which are capable of producing spallation reactions in heavy metal targets, thus yielding large … more

Date: January 1, 1977

Creator: Steinberg, M.; Takahashi, H.; Ludewig, H. & Powell, J.R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Slow neutron leakage spectra from spallation neutron sources

An efficient technique is described for Monte Carlo simulation of neutron beam spectra from target-moderator-reflector assemblies typical of pulsed spallation neutron sources. The technique involves the scoring of the transport-theoretical probability that a neutron will emerge from the moderator surface in the direction of interest, at each collision. An angle-biasing probability is also introduced which further enhances efficiency in simple problems. These modifications were introduced into t… more

Date: February 1, 1980

Creator: Das, S.G.; Carpenter, J.M. & Prael, R.E.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Ablation of material by front surface spallation

Laser irradiation can be utilized to remove (i.e., ablate) material in a controlled manner by a hydrodynamic process, referred to as front surface spallation. In this process, a thin layer next to a free surface is heated to a level (below vaporization) so rapidly that it cannot undergo thermal expansion during laser heating. This generates a stress pulse, which propagates both inward and toward the free surface, with an initial amplitude that can be calculated using the Grueneisen coefficient.… more

Date: January 1, 1991

Creator: Dingus, R. S. & Scammon, R. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Analytic model for surface ground motion with spall induced by underground nuclear tests

This report provides a detailed presentation and critique of a model used to characterize the surface ground motion following a contained, spalling underground nuclear explosion intended for calculation of the resulting atmospheric acoustic pulse. Some examples of its use are included. Some discussion of the general approach of ground motion model parameter extraction, not dependent on the specific model, is also presented.

Date: April 1, 1982

Creator: MacQueen, D.H.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Plastic box: a 4. pi. detector for intermediate energy heavy ion physics

A 4..pi.. array of plastic scintillator has been constructed and used in conjunction with high resolution solid state detectors. The array is employed principally to discriminate multinucleon transfer reactions from three-body (or more) final states. It should be useful for a broad class of experiments in which a global charged particle anticoincidence is required.

Date: October 1, 1983

Creator: Van Bibber, K.; Countryman, P.J.; Murphy, M.J.; Chan, Y.D.; Stokstad, R.G.; Tserruya, I. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Laser-ablation processes

The various mechanisms by which ablation of materials can be induced with lasers are discussed in this paper. The various ablation processes and potential applications are reviewed from the threshold for ablation up to fluxes of about 10{sup 13} W/cm{sup 2}, with emphasis on three particular processes; namely, front-surface spallation, two-dimensional blowoff, and contained vaporization.

Date: January 1, 1992

Creator: Dingus, R. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Non-reactor neutron irradiation facility: the Argonne Intense Pulsed Neutron Source

A new generation of neutron sources is just coming into existence with great promise for the future. These sources are based on neutron production by spallation from the interaction of high energy protons with a heavy metal target. Currently the highest flux facility of this type is the Intense Pulsed Neutron Source at Argonne National Laboratory. This machine is also unique in its dedication to both slow-neutron scattering and fast-neutron damage studies.

Date: October 1, 1983

Creator: Birtcher, R. C. & Scott, T. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Status report on the WNR/PSR pulsed spallation neutron source at the Los Alamos National Laboratory

Much progress has been made in WNR/PSR facility development and in planning and implementing a full research program since the last ICANS meeting. Construction of the PSR continues on schedule, a significant neutron scattering research program is under way at the WNR that can continue through the construction period, and a formal neutron scattering user program was begun this year. The problem of bothersome backgrounds at the WNR has been solved, and a versatile and effective target-moderator d… more

Date: January 1, 1983

Creator: Bowman, C. D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Application of particle beams to geothermal well drilling. Final report

Experiments involving shock spalling in rock are described. Also included are the application of electron beams to the excavation of rock tunnels, characteristics of particle beams for rock spalling, hypothetical drilling systems based on particle beams, and potential economics of particle beam drilling. There is no indication that particle beam drilling will be less expensive than conventional drilling. (MHR)

Date: September 1, 1979

Creator: Beebee, J. & Ogle, W.E.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Status of neutron dosimetry and damage analysis for the fusion materials program

The status of neutron flux and spectral measurements is described for fusion material irradiations at reactor, T(d,n), Be(d,n), and spallation neutron sources. Such measurements are required for the characterization of an irradiation in terms of displacement damage, gas and transmutant production. Emphasis is placed on nuclear data deficiencies with specific recommendations for cross section measurements and calculations.

Date: January 1, 1979

Creator: Greenwood, L.R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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He-jet system to study short-lived fission-product nuclei at LAMPF

Experiments have been performed at LAMPF which demonstrate the feasibility of utilizing a He-jet system to transport fission products to an on-line mass separator from a target chamber mounted in the 800-MeV, >600..mu..A main proton beam. Activities of essentially all elements produced are transported with about 60% absolute efficiency, both for fission reactions and spallation reactions. Transport times are short enough to allow study of activities with half-lives as short as 300 ms. Technical… more

Date: January 1, 1983

Creator: Talbert, W. L.; Bunker, M. E. & Starner, J. W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Los Alamos high-current proton storage ring: a status report

The Proton Storage Ring (PSR), whose installation was recently completed at Los Alamos, is a fast-cycling high-current accumulator designed to produce intense 800 MeV proton pulses for driving a spallation neutron source. The ring converts long beam pulses from the LAMPF linear accelerator into short bunches well matched to requirements of a high-resolution neutron-scattering materials science program. The initial performance goal for this program is to provide 100-..mu..A average current at th… more

Date: January 1, 1985

Creator: Lawrence, G. P.; Hardekopf, R. A.; Jason, A. J.; Clout, P. N. & Sawyer, G. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Accelerator breeders: will they replace liquid metal fast breeders

Investigation of accelerator breeders at Brookhaven National Laboratory indicate that the AB-LWR fuel cycle is economically competitive with the LMFBR fuel cycle. The same can be said about the accelerator breeder-High Temperature Gas Reactor symbiosis. This system appears to be very competitive with the added real advantage of superior safety and proliferation resistance. This discussion would be incomplete if the real competitor to accelerator breeding was not mentioned, namely Fusion Hybrid … more

Date: June 1, 1983

Creator: Grand, P.; Powell, J.R.; Steinberg, M. & Takahashi, H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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The possible use of a spallation neutron source for neutron capture therapy with epithermal neutrons

Spallation is induced in a heavy material by 72 MeV protons. The hereby produced neutrons with essentially an evaporation spectrum with a peak energy of less than 2 MeV are moderated in two steps, first in iron, and then in carbon. Results from neutron fluence measurements in a perspex phantom placed close to the moderator are presented. Monte Carlo calculations of neutron fluence in a water phantom are also presented under some chosen configurations of spallation source and moderator. The calc… more

Date: January 1, 1989

Creator: Grusell, E.; Conde, H.; Larsson, B.; Roennqvist, T.; Sornsuntisook, O.; Crawford, J. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Assessment of Cavitation-Erosion Resistance of Potential Pump Impeller Materials for Mercury Service at the Spallation Neutron Source

Using a standard vibratory horn apparatus, the relative cavitation-erosion resistance of a number of cast alloys in mercury was evaluated to facilitate material selection decisions for Hg pumps. The performance of nine different alloys - in the as-cast condition as well as following a case-hardening treatment intended to increase surface hardness - was compared in terms of weight loss and surface profile development as a function of sonication time in Hg at ambient temperature. The results indi… more

Date: March 1, 2007

Creator: Pawel, Steven J

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Laser Drilling: Drilling with the Power of Light Phase 1: Feasibility Study

A laser drilling research team was formed from members of academia, industry and national laboratory to explore the feasibility of using modern high-powered lasers to drill and complete oil and gas wells. The one-year Phase 1 study discussed in this report had the goals of quantifying the amount of pulsed infrared laser energy needed to spall and melt rock of varying lithologies and to investigate the possibility of accomplishing the same task in water under atmospheric conditions. Previous wor… more

Date: September 1, 2001

Creator: Gahan, Brian C.; Parker, Richard A.; Graves, Ramona; Batarseh, Samih; Reed, Claude B.; Xu, Zhiyue et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Mechanisms Associated with Rumpling of Pt-Modified Beta-NiAl Coatings

The formation of surface undulations (i.e. rumpling) at the bond coat/thermally grown oxide (TGO) interface has been shown to cause failure by spallation of the ceramic top coat in aero-turbine systems. Many mechanisms have been proposed concerning the cause of these surface distortions; however, there is little agreement on what may be the dominating cause of the rumpling behavior. Of there mechanisms, the reversible phase transformation from a cubic {beta}-NiAl structure to a face centered te… more

Date: December 1, 2007

Creator: Henderkott, Joseph Peter

Item Type: Thesis or Dissertation

Partner: UNT Libraries Government Documents Department

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Assessment of End-of-Life Behavior of the Surface Modification to Improve Cavitation-Erosion Resistance in the Mercury Target at the Spallation Neutron Source

The cavitation-erosion resistance of the Kolsterised{reg_sign} layer on annealed or cold-worked substrates of 316LN stainless steel has been examined in mercury using a vibratory horn technique and extended exposure periods intended to expose 'end-of-life' performance characteristics. The Kolsterised{reg_sign} layer tends to remain protective--as evidenced by modest steady-state weight loss and surface roughness increases, only isolated pitting, and limited wetting by mercury--until the protect… more

Date: June 1, 2007

Creator: Pawel, Steven J

Item Type: Report

Partner: UNT Libraries Government Documents Department

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AN OVERVIEW OF THE SNS ACCELERATOR MECHANICAL ENGINEERING.

The Spallation Neutron Source (SNS*) is an accelerator-based neutron source currently nearing completion at Oak Ridge National Laboratory. When completed in 2006, the SNS will provide a 1 GeV, 1.44 MW proton beam to a liquid mercury target for neutron production. SNS is a collaborative effort between six U.S. Department of Energy national laboratories and offered a unique opportunity for the mechanical engineers to work with their peers from across the country. This paper presents an overview o… more

Date: June 23, 2006

Creator: HSEUH, H.; LUDWIG, H.; MAHLER, G.; PAI, C.; PEARSON, C.; RANK, J. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department