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in creator/contributor: "Sale, K"

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Radioactive ion beam research at LLNL

In this paper we discuss efforts underway at LLNL to develop the technology for the measurement of proton and alpha-particle reactions with unstable nuclei which are necessary for understanding the nucleosynthesis and energy generation in hot hydrogen-burning environments. 16 refs., 5 figs.

Date: August 1, 1985

Creator: Mathews, G. J.; Bauer, R. W.; Haight, R. C. & Sale, K. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Primordial nucleosynthesis in inhomogeneous cosmologies:. cap omega. = 1 with baryonic dark matter

We consider the constraints on ..cap omega.. from primordial nucleosynthesis in inhomogeneous cosmologies. We find that allowance for isothermal fluctuations significantly weakens the upper bound on the average value of ..cap omega.. derived from the standard big bang. Under the plausible additional assumption that regions of high baryon density are preferentially absorbed into cold dark matter, the constraints from primordial nucleosynthesis can be satisfied for large values of ..cap omega.., … more

Date: September 1, 1986

Creator: Mathews, G. J. & Sale, K. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Radioactive ion beam research at Lawrence Livermore National Laboratory

Several modifications and additions have been made to improve the radioactive beam facility at Livermore with the main aim of measuring the cross section for /sup 7/Be(p,..gamma..)/sup 8/B (which is important in determining the solar neutrino flux) and other reactions of astrophysical interest. The quadrupole sextuplet spectrometer has been upgraded by inserting an electrostatic deflection element near the midpoint and by installing a movable beam stop near the /sup 7/Be production target. Thes… more

Date: September 1, 1986

Creator: Sale, K. E.; Bauer, R. W.; Boyd, R. N.; Mathews, G. J.; Haight, R. C. & Corn, P. B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

A parameter study of the r process

We consider the r-process production of actinide nuclei from a high temperature nucleon gas in a model which is most favorable for the r process. In this way, we can place upper limits on the value of the free electron fraction, Y/sub e/, of the material which experiences the r process. We find that for a broad range of initial nucleon densities, Y/sub e/ must be small (close to that for equilibrium neutron star matter). 11 refs., 2 figs.

Date: September 1, 1987

Creator: Sale, K. E. & Mathews, G. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Conversion-electron experiment to characterize the decay of the /sup 237/Np shape isomer

Conversion electrons from the decay of low-lying levels of /sup 237/Np have been measured to detect the population of these levels by gamma-ray decay of the /sup 237/Np shape isomer. Analysis of the 208-keV transition L conversion-electron peak gives an upper limit of about 17 ..mu..b for the population of the 3/2/sup -/ 267-keV level in /sup 237/Np from the shape isomer decay. Model calculations are compared with the measured limit. Improvements are suggested for this experiment. 9 refs., 4 fi… more

Date: December 8, 1987

Creator: Henry, E. A.; Becker, J. A.; Bauer, R. W.; Gardner, D. G.; Decman, D. J.; Meyer, R. A. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Benchmark field study of deep neutron penetration

A unique benchmark neutron field has been established at the Lawrence Livermore National Laboratory (LLNL) to study deep penetration neutron transport. At LLNL, a tandem accelerator is used to generate a monoenergetic neutron source that permits investigation of deep neutron penetration under conditions that are virtually ideal to model, namely the transport of mono-energetic neutrons through a single material in a simple geometry. General features of the Lawrence Tandem (LATAN) benchmark field… more

Date: June 10, 1991

Creator: Morgan, J. F.; Sale, K. (Lawrence Livermore National Lab., CA (USA) ); Gold, R.; Roberts, J. H. & Preston, C. C. (Metrology Control Corp., Richland, WA (USA) )

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Numerical modeling of nonintrusive inspection systems

A wide variety of nonintrusive inspection systems have been proposed in the past several years for the detection of hidden contraband in airline luggage and shipping containers. The majority of these proposed techniques depend on the interaction of radiation with matter to produce a signature specific to the contraband of interest, whether drugs or explosives. In the authors` role as diagnostic specialists in the Underground Test Program over the past forty years, L-Division of the Lawrence Liv… more

Date: December 1, 1992

Creator: Hall, J.; Morgan, J. & Sale, K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Signal predictions for a proposed fast neutron interrogation method

We have applied the Monte Carlo radiation transport code COG) to assess the utility of a proposed explosives detection scheme based on neutron emission. In this scheme a pulsed neutron beam is generated by an approximately seven MeV deuteron beam incident on a thick Be target. A scintillation detector operating in the current mode measures the neutrons transmitted through the object as a function of time. The flight time of unscattered neutrons from the source to the detector is simply related … more

Date: December 1, 1992

Creator: Sale, K. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Radiative capture mechanisms in the {sup 89}Y({rvec p},{gamma}) reaction

We have measured the spectra of gamma rays from approximately 14 MeV to the endpoint in the {sup 89}Y({rvec p},{gamma}) reaction with 19.6 MeV polarized protons from the TUNL tandem accelerator. Gamma spectra were measured with a pair of 25.4 cm {times} 25.4 cm anticoincidence shielded NaI detectors at angles of 30, 55, 90, 125, and 150{degrees} with respect to the incident beam. The {gamma}-ray spectra show significant analyzing powers and forward peaking of the angular distributions. These fe… more

Date: July 28, 1993

Creator: Parker, W. E.; Dietrich, F. S.; Sale, K. E.; Kammeraad, J. E.; Luke, S. J.; Weller, H. R. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Overview and applications of the Monte Carlo radiation transport kit at LLNL

Modern Monte Carlo radiation transport codes can be applied to model most applications of radiation, from optical to TeV photons, from thermal neutrons to heavy ions. Simulations can include any desired level of detail in three-dimensional geometries using the right level of detail in the reaction physics. The technology areas to which we have applied these codes include medical applications, defense, safety and security programs, nuclear safeguards and industrial and research system design and… more

Date: June 23, 1999

Creator: Sale, K E

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Pulse height spectrum measurement experiment for code benchmarking: first results

The authors have completed a set of gamma-ray pulse height benchmark experiments using a high purity germanium detector to measure absolute counting rate spectra from {sup 60}Co, {sup 137}Cs and {sup 57}Co isotopic sources. The detector was carefully shielded and collimated so that the geometry of the system was completely known. The measured absolute pulse height spectrum counting rates as a function of detector position relative to the source are compared to energy deposit spectra calculated … more

Date: October 27, 2000

Creator: Sale, K E; Hall, J M & Brown, C M

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Screening of Maritime Containers to Intercept Weapons of Mass Destruction

The goal of our research was to address the problem of detection of weapons of mass destruction (WMD) materials within containers in common use on commercial cargo trafficking. LLNL has created an experimental test bed for researching potential solutions using (among other techniques) active interrogation with neutrons. Experiments and computational modeling were used to determine the effectiveness of the technique. Chemical weapons materials and high explosives can be detected using neutron ac… more

Date: February 18, 2004

Creator: Manatt, D. R.; Sleaford, B.; Schaffer, T.; Accatino, M. R.; Slaughter, D.; Mauger, J. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

COG validation: SINBAD Benchmark Problems

We validated COG, a 3D Monte Carlo radiation transport code, against experimental data and MNCP4C simulations from the Shielding Integral Benchmark Archive Database (SINBAD) compiled by RSICC. We modeled three experiments: the Osaka Nickel and Aluminum sphere experiments conducted at the OKTAVIAN facility, and the liquid oxygen experiment conducted at the FNS facility. COG results are in good agreement with experimental data and generally within a few % of MCNP results. There are several possib… more

Date: February 23, 2004

Creator: Lent, E M; Sale, K E; Buck, R M & Descalle, M

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Current Status of Radiation Transport Tools for Proliferation and Terrorism Prevention

We present the current status and future plans for the set of calculational tools and data bases developed and maintained at LLNL. The calculational tools include the Monte Carlo codes TART and COG as well as the deterministic code ARDRA. In addition to these codes presently in use there is a major development effort for a new massively parallel transport code. An important part of the capability we're developing is a sophisticated user interface, based on a commercial 3-D modeling product, to … more

Date: September 13, 2004

Creator: Sale, K E

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

COG - Publicly Available Now to Criticality Safety Practitioners

COG is a modern, general-purpose, high fidelity, multi-particle transport code with a long history of use in criticality safety studies at the Lawrence Livermore National Laboratory. This code was released to the Radiation Safety Information Computational Center (RSICC) for distribution to the public for the first time in January 2006. This paper provides an overview of the code development history, a description of features and capabilities of interest to the criticality safety practitioner, a… more

Date: September 12, 2006

Creator: Buck, R M; Cullen, D E; Heinrichs, D P; Lent, E M; Nielsen, Jr, D E & Sale, K E

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Neutron Correlations in Special Nuclear Materials, Experiments and Simulations

Fissile materials emit neutrons with an unmistakable signature that can reveal characteristics of the material. We describe here measurements, simulations, and predicted signals expected and prospects for application of neutron correlation measurement methods to detection of special nuclear materials (SNM). The occurrence of fission chains in SNM can give rise to this distinctive, measurable time correlation signal. The neutron signals can be analyzed to detect the presence and to infer attribu… more

Date: June 5, 2007

Creator: Verbeke, J. M.; Dougan, A.; Nakae, L. F.; Sale, K. E. & Snyderman, N. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Results of LLNL investigation of NYCT data sets

Upon examination we have concluded that none of the alarms indicate the presence of a real threat. A brief history and results from our examination of the NYCT ASP occupancy data sets dated from 2007-05-14 19:11:07 to 2007-06-20 15:46:15 are presented in this letter report. When the ASP data collection campaign at NYCT was completed, rather than being shut down, the Canberra ASP annunciator box was unplugged leaving the data acquisition system running. By the time it was discovered that the ASP… more

Date: August 1, 2007

Creator: Sale, K.; Harrison, M.; Guo, M. & Groza, M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Radioactive Threat Detection with Scattering Physics: A Model-Based Application

The detection of radioactive contraband is a critical problem in maintaining national security for any country. Emissions from threat materials challenge both detection and measurement technologies especially when concealed by various types of shielding complicating the transport physics significantly. The development of a model-based sequential Bayesian processor that captures both the underlying transport physics including scattering offers a physics-based approach to attack this challenging … more

Date: January 21, 2010

Creator: Candy, J V; Chambers, D H; Breitfeller, E F; Guidry, B L; Verbeke, J M; Axelrod, M A et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Model-Based Detection of Radioactive Contraband for Harbor Defense Incorporating Compton Scattering Physics

The detection of radioactive contraband is a critical problem is maintaining national security for any country. Photon emissions from threat materials challenge both detection and measurement technologies especially when concealed by various types of shielding complicating the transport physics significantly. This problem becomes especially important when ships are intercepted by U.S. Coast Guard harbor patrols searching for contraband. The development of a sequential model-based processor that… more

Date: March 2, 2010

Creator: Candy, J V; Chambers, D H; Breitfeller, E F; Guidry, B L; Verbeke, J M; Axelrod, M A et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department