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in creator/contributor: "Langner, D.G."

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U.S. Support Program tasks

In the fall of 1993, President Clinton announced before the United Nations General Assembly, that the US would voluntarily offer excess fissile material of weapons origin to International Atomic Energy Agency (IAEA) safeguards. There are presently five US Support Program tasks at work. Three are complete, and two are underway. Reports are available from two of the completed SP-1s; a draft is in preparation for the third. These tasks are: (1) plutonium scrap multiplicity counter at Hanford; (2) … more

Date: September 1, 1998

Creator: Langner, D. G.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Geometry-based multiplication-corrected analysis for neutron coincidence assay of impure plutonium materials

We have developed a technique to assay impure, plutonium-bearing materials using passive neutron coincidence counting. The technique can be applied to any impure, plutonium-bearing material category whose matrix constituents are approximately constant, whose self- multiplication is low-to-moderate, whose plutonium isotopic composition is known and not substantially varying, and whose bulk geometry is measurable or can be derived. The technique requires a set of reference materials with well-cha… more

Date: January 1, 1991

Creator: Langner, D. G. & Russo, P. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Pyrochemical multiplicity counter development

Impure plutonium-bearing materials from pyrochemical processes often display both significant self-multiplication and variable ({alpha},n) reaction rates. Standard neutron coincidence counting techniques usually fail to accurately measure these materials. Neutron multiplicity counters measure the third moment of the neutron multiplicity distribution and thus make it possible to deduce the fertile plutonium mass of a sample even when both the self-multiplication and the ({alpha},n) reaction rate… more

Date: January 1, 1991

Creator: Langner, D. G.; Dytlewski, N. & Krick, M. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Measurement of special nuclear material concentrations in solution by absorption edge densitometry

Absorption-edge densitometry is reviewed and examples of data obtained at the L/sub III/-edge of uranium are presented. Expressions are derived which allow the estimation of assay errors as a function of the transmission source intensity and the sample thickness for particular ranges of SNM concentration and matrix density. Specific examples are given and discussed.

Date: January 1, 1977

Creator: Tape, J. W.; Langner, D. G.; Parker, J. L. & Canada, T. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Digital reconstruction of a coded image obtained with a nonredundant pinhole array

A coded image or pseudohologram, obtained optically with a nonredundant pinhole array imaging aperture was digitized in a 512 x 512 format. Images were reconstructed digitally. The reconstruction scheme, a deconvolution in the Fourier domain, is presented. The applicability of this technique to a real-time imaging system is discussed.

Date: January 1, 1976

Creator: Han, K. S.; Berzins, G. J.; Mason, D. S. & Langner, D. G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

ATTRIBUTE VERIFICATION SYSTEMS WITH INFORMATION BARRIERS FOR CLASSIFIED FORMS OF PLUTONIUM IN THE TRILATERAL INITIATIVE

No Description Available.

Date: October 1, 2001

Creator: LANGNER, D. G.; HSUE, S. T. & AL, ET

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Nuclear safeguards applications of energy-dispersive absorption edge densitometry

The principles and techniques of absorption edge densitometry in the energy-dispersive mode are summarized as they apply to the nondestructive assay of special nuclear materials. Five existing field instruments, designed for special nuclear materials accounting measurements, are described. Results of the testing of these instruments as well as recent laboratory results are used to define the capabilities of the technique for special nuclear materials accounting. Possibilities for future applica… more

Date: January 1, 1980

Creator: Russo, P. A.; Hsue, S. T.; Langner, D. G. & Sprinkle, J. K., Jr.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

L/sub III/-edge densitometer operations manual

This report describes briefly the operation and maintenance of an L/sub III/-edge densitometer. The instrument is optimized for 50 g/l of special nuclear material, but yields better than 0.5% precision in 1000-s assays over a concentration range of 10 to 90 g/l. It can determine uranium and plutonium concentrations in a 2-ml sample cell and has been designed for both static and flowing solution measurements.

Date: October 1, 1981

Creator: Sprinkle, J. K. Jr.; Johnson, S. S.; Langner, D. G. & Russo, P. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

A large multiplicity counter for the measurement of bulk plutonium

The authors have considered the problem of designing a thermal neutron counter for the neutron multiplicity measurement of large, high-mass plutonium items. Three neutron multiplicity counters have been built at Los Alamos to date; two are used for in-plant applications. The third counter is an experimental prototype and is used for research. The sample cavities of these counters can accommodate only relatively small samples. The largest item that can be measured optimally by the largest of the… more

Date: August 1, 1994

Creator: Langner, D. G.; Krick, M. S. & Kroncke, K. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Evaluation of in-plant neutron coincidence counters for the measurement of molten salt extraction residues

Americium is extracted from plutonium by a molten salt extraction (MSE) process. The residual americium-laden salts are a significant waste stream in this pyrochemical purification process. Rapid assay of MSE residues is desirable to minimize the exposure of personnel to these often high-level emissions. However, the quantitative assay of plutonium in MSE residues is difficult. Variable, unknown (a,n) rates and variable emitted-neutron energy spectra preclude the use of standard neutron coincid… more

Date: August 1, 1993

Creator: Langner, D. G.; Russo, P. A. & Wachter, J. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Energy dependent bias in plutonium verification measurements using thermal neutron multiplicity counters

Multiplicity analysis algorithms are extended to include the effect of ({alpha}, n) neutron energies on the detector efficiencies, induced fission probabilities, and induced fission factorial moments. The analysis is restricted to plutonium oxide. Bias is calculated as a function of ({alpha}, n) neutron energy for six thermal neutron coincidence counters: HLNC, AWCC, 3RMC, PSMC, PYRO, and 5RMC. Ring ratio data for the 3RMC are used to reduce energy dependent bias in the verification of impure p… more

Date: October 1, 1997

Creator: Krick, M. S.; Langner, D. G. & Stewart, J. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Assay of impure plutonium oxide with the large neutron multiplicity counter for IAEA verification of excess weapons material at the Rocky Flats Environmental Technology Site

The large neutron multiplicity counter (LNMC), also known as the 30-gal.-drum neutron multiplicity counter, has now been used successfully by the International Atomic Energy Agency (IAEA) for the Initial Physical Inventory Verification (IPIV) and the first annual Physical Inventory Verification (PIV) of excess weapons plutonium oxide at the Rocky Flats Environmental Technology Site (RFETS). These excess plutonium oxide materials contain a variety of impurities. They are stored two cans to a 10-… more

Date: November 1, 1997

Creator: Langner, D. G.; Franco, J. B. & Larsen, R. K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The application of neutron multiplicity counting to the assay of bulk plutonium bearing materials at RFETS and LLNL

In the past several years, several facilities have identified a need for a large multiplicity counter to support safeguards of excess weapons materials and the measurement control and accountability of large, unusual samples. The authors have designed and fabricated two large thermal neutron multiplicity counters to meet this need at two DOE facilities. The first of these counters was built for Rocky Flats Environmental Test Site for use in the initial inventory inspection of excess weapons plu… more

Date: October 1, 1995

Creator: Langner, D. G.; Krick, M. S. & Kroncke, K. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

In-plant evaluation of a uranium NDA system

A uranium solution assay system was developed to allow accurate, timely process control, accountability, and criticality data to be obtained. In it, Ge(Li) ..gamma..-ray spectroscopy is integrated with an interactive computer software package. The U concentation range is divided into three material categories: raffinates and distillates, leach solutions, and concentrated leach solutions. (DLC)

Date: January 1, 1979

Creator: Baxman, H. R.; Langner, D. G.; Sprinkle, J. K.; Sampson, T. E. & Canada, T. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Active neutron multiplicity counting of bulk uranium

This paper describes a new nondestructive assay technique being developed to assay bulk uranium containing kilogram quantities of {sup 235}U. The new technique uses neutron multiplicity analysis of data collected with a coincidence counter outfitted with AmLi neutron sources. We have calculated the expected neutron multiplicity count rate and assay precision for this technique and will report on its expected performance as a function of detector design characteristics, {sup 235 }U sample mass, … more

Date: January 1, 1991

Creator: Ensslin, N.; Krick, M. S.; Langner, D. G. & Miller, M. C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The state-of-the-art of thermal neutron multiplicity counting

Neutron multiplicity counting is a maturing technology. It has been implemented at many facilities to address the increasing need to rapidly measure impure plutonium bearing materials. At Hanford Site and Rocky Flats Environmental Technology Site, multiplicity counting has also been used with excellent results by the International Atomic Energy Agency to verify excess plutonium inventories now under their safeguards. Neutron multiplicity counting as currently implemented, however, will not addr… more

Date: November 1, 1997

Creator: Langner, D. G.; Krick, M. S.; Stewart, J. E. & Ensslin, N.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Installation and calibration of the oversized low-level package counter at Los Alamos National Laboratory

With the importance of safeguards in production facilities, the Los Alamos National Laboratory Plutonium Facility has installed a neutron slab counter to facilitate the measurement of low-level waste packaged in 4 ft {times} 4 ft {times} 8 ft crates. In the past, oversized packages were measured by a gamma technique to assess holdup. The measurement was time-consuming and cumbersome, and the efficiency was questionable. The slab counter has alleviated the time and efficiency problems of the gam… more

Date: August 1, 1994

Creator: Long, S. M.; Langner, D. G.; Foster, L. A. & Malcom, J. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Thermal neutron multiplicity measurements using the pyrochemical multiplicity counter at Lawrence Livermore National Laboratory

The pyrochemical multiplicity counter designed and built at Los Alamos has been undergoing tests and evaluation at Lawrence Livermore National Laboratory (LLNL). Measurements have been performed using a variety of plutonium oxide and metal materials. The pyrochemical multiplicity counter uses the information contained in the higher moments of the neutron multiplicity distribution to deduce the three unknowns in the assay problem: {sup 240}Pu-effective mass, ({alpha},n) neutron rate, and self-mu… more

Date: August 1, 1993

Creator: Langner, D. G.; Krick, M. S.; Parks, D. R. & Hooper, K. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Neutron multiplicity assay of impure materials using four different neutron counters

During an advanced IAEA inspector training course given at Los Alamos in November, 1997, the opportunity existed for an intercomparison study of various neutron detectors to quantify measurement performance using pure and impure plutonium oxide and mixed uranium-plutonium oxide (MOX) items. Because of the cost of counters designed specifically for multiplicity analysis, it was desired to explore the limits of other, less costly and less efficient detectors. This paper presents and intercompares… more

Date: December 1, 1998

Creator: Stewart, J. E.; Langner, D. G. & Wenz, T. R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Evaluation of an L/sub III/ x-ray absorption-edge densitometer for assay of mixed uranium-plutonium solutions

An L/sub III/ x-ray absorption-edge densitometer (XRAED), designed and built at Los Alamos Scientific Laboratory, has been evaluated at Savannah River Laboratory for the assay of uranium and plutonium in process solutions. Fro 2000-second data collection, the precisions (95% confidence level) for uranium assays varied +- 1.04% at 10 g of uranium per liter to 0.34% at 45 g/L, and plutonium assays varied from +- 6.7% at 2 g of plutonium per liter to +- 2.2% at 10 g/L. Hydroxylamine nitrate, a red… more

Date: January 1, 1979

Creator: Mosley, W. C.; Thompson, M. C.; Reynolds, L. W.; Russo, P.; Canada, T. R. & Langner, D. G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Neutron multiplicity counter development

We have designed and built two multiplicity counters to test the usefulness of multiplicity counting for the safeguards assay of plutonium-bearing materials. The first prototype counter has been characterized and a variety of plutonium-bearing materials have been measured with it. Assays accurate to {approximately}0.7% have been obtained for both pure and impure plutonium oxide samples in reasonable measurement times. Assays accurate to {approximately}5% have been obtained for metal samples. A … more

Date: January 1, 1991

Creator: Langner, D. G.; Krick, M. S.; Ensslin, N.; Bosler, G. E. & Dytlewski, N.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Pyrochemical neutron multiplicity counter design

Pyrochemical process materials are difficult to measure using conventional neutron counting methods because of significant self- multiplication and variable ({alpha},n) reaction rates. Multiplicity counters measure the first three moments of the neutron multiplicity distribution and thus make it possible to determine sample mass even when multiplication and ({alpha},n) rate are unknown. A new multiplicity counter suitable for inplant measurement of pyrochemical process materials has been design… more

Date: January 1, 1990

Creator: Langner, D. G.; Ensslin, N. & Krick, M. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Measurement of the assay precision of the active neutron multiplicity technique

This paper describes a measurement of the precision of the new active-neutron-multiplicity assay technique, which is currently under development for bulk uranium containing kilogram quantities of {sup 235}U. The new technique analyzes neutron multiplicity data collected with a coincidence counter outfitted with AmLi neutron sources. We report on the observed assay precision and the implications for field use of the technique.

Date: August 1, 1992

Creator: Ensslin, N.; Krick, M. S.; Langner, D. G.; Miller, D. W. & Miller, M. C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Measurement of the assay precision of the active neutron multiplicity technique

Date: January 1, 1992

Creator: Ensslin, N.; Krick, M. S.; Langner, D. G.; Miller, D. W. & Miller, M. C.

Item Type: Article

Partner: UNT Libraries Government Documents Department