Download or read book Bias in Segmented Gamma Scans Arising from Size Differences Between Calibration Standards and Assay Samples written by Thomas E. Sampson and published by . This book was released on 1991 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bias in Segmented Gamma Scans Arising from Size Differences Between Calibration Standards and Assay Samples written by Thomas E. Sampson and published by . This book was released on 1991 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1993-11 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bias Investigation of a 55 gallon Drum sized Segmented Gamma Scanner written by and published by . This book was released on 1993 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper addresses a series of studies undertaken while fulfilling the measurement requirements for certification of a 55-gallon drum-sized segmented gamma scanner to be used at the plutonium facility (TA-55) at Los Alamos. These studies were initiated to investigate anomalies seen in the data as well as gain a quantifiable understanding of effects caused by using standards of considerably different geometric proportions than the assay items, oftentimes necessitated due to lack of adequate standards. The first investigation concerned effects caused by items not being exactly centered on the measurement table. The remaining studies involved establishing the magnitude of the bias induced by so-called ''end effects'' as well as by size differences between calibration standards and assay items. In order to unravel the above effects, can and drum parameter files were interchangeably employed in conjunction with comparisons of the instrument calibrations obtained with can-sized standards and 55-gallon drum standards. The paper will discuss the results and the magnitude of the observed effects.
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1992 with total page 1044 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Point source Calibration of a Segmented Gamma ray Scanner written by and published by . This book was released on 1994 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: For a conventional segmented gamma-ray scanner (SGS) in which the sample is rotated continuously within a fixed detector field of view, the data will not support alternatives to the assumption that the gamma-emitting nuclides and the matrix in which they reside are uniformly distributed. This homogeneity assumption permits the geometry of samples and calibration standards to be approximated by that of a non attenuating line source on the axis of rotation. Other common SGS assumptions are that the detector is perfectly collimated, that its response is flat over its field of view, and that it can be approximated adequately by a line. All of these assumption have led to a preference for homogeneous calibration standards. Preparation and certification of such calibration standards are usually difficult and expensive. Storage and transportation of SGS standards can be inconvenient or even quite troublesome. The authors have proposed and tested an alternative method of SGS calibration that only requires a point-source standard. The proposed technique relies on the empirical determination of a normalized two-dimensional detector response and the measurement of the count rate from a point-source standard located at the response apex. With these data, the system's response to a distributed, homogeneous samples can be predicted using numerical integration. Typical biases measured using a commercially available SGS calibrated with a point source have been less than 2%.
Download or read book Government Reports Annual Index written by and published by . This book was released on 1992 with total page 1844 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Annual Book of ASTM Standards written by ASTM International and published by . This book was released on 2004 with total page 1252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Results of a Comparison Study Using Tomographic and Segmented Gamma Scanner Technology written by and published by . This book was released on 2004 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to support the many on-going research and programmatic activities at Los Alamos Plutonium and Chemistry and Metallurgy Research (CMR) Facilities in as accurate, efficient, and cost-effective manner possible, every reasonable effort is made to equip the nondestructive assay (NDA) laboratories with the most modern and technologically advanced instrumentation available. Recently, new state-of-the-art tomographic gamma scanner (TGS) instruments were installed to replace aging and outmoded segmented gamma scanner (SGS) instruments. Through the implementation of a translation axis, in addition to the vertical and rotation axes of the SGS, the TGS technique is able to employ axial tomography to determine the spatial distribution and quantity of nuclear material using high-resolution gamma-ray spectroscopy. Because the attenuation matrix and source distributions are known more accurately than with the SGS technology, biases due to matrix and source distributions should be reduced. In principle, a single calibration should suffice for the determination of isotopic mass for a wide range of material and matrix types. A number of questions naturally arise concerning these purported advantages of the TGS. Perhaps the most fundamental of these is to understand how the TGS measurement results compare with those of a typical SGS on the same well-characterized standards differing in matrix and material type. To that end, the TGS operating parameters were optimized to assay 55-gallon drum waste identical to that measured by our SGS. The calibration and measurement results on these standards, placed in typical low-density waste matrices, are presented and discussed. These results should enable more confident use of the TGS as well as point the way toward even more studies to enable more effective employment of the new TGS technology.
Download or read book Transactions written by American Nuclear Society and published by . This book was released on 1987 with total page 1392 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Use of Calibration Standards and the Correction for Sample Self attenuation in Gamma ray Nondestructive Assay written by Jack L. Parker and published by . This book was released on 1984 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Use of Calibration Standards and the Correction for Sample Self attenuation in Gamma ray Nondestructive Assay written by Jack L. Parker and published by . This book was released on 1984 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The efficient use of appropriate calibration standards and the correction for the attenuation of the gamma rays within an assay sample by the sample itself are two important and closely related subjects in gamma-ray nondestructive assay. Much research relating to those subjects has been done in the Nuclear Safeguards Research and Development program at the Los Alamos National Laboratory since 1970. This report brings together most of the significant results of that research. Also discussed are the nature of appropriate calibration standards and the necessary conditions on the composition, size, and shape of the samples to allow accurate assays. Procedures for determining the correction for the sample self-attenuation are described at length including both general principles and several specific useful cases. The most useful concept is that knowing the linear attenuation coefficient of the sample (which can usually be determined) and the size and shape of the sample and its position relative to the detector permits the computation of the correction factor for the self-attenuation. A major objective of the report is to explain how the procedures for determining the self-attenuation correction factor can be applied so that calibration standards can be entirely appropriate without being particularly similar, either physically or chemically, to the items to be assayed. This permits minimization of the number of standards required to assay items with a wide range of size, shape, and chemical composition. 17 references, 18 figures, 2 tables.
Download or read book Radioactive Waste Management written by and published by . This book was released on 1995-04 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Use of Calibration Standards and the Correction for Sample Self attenuation in Gamma ray Nondestructive Assay written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The efficient use of appropriate calibration standards and the correction for the attenuation of the gamma rays within an assay sample by the sample itself are two important and closely related subjects in gamma-ray nondestructive assay. Much research relating to those subjects has been done in the Nuclear Safeguards Research and Development program at the Los Alamos National Laboratory since 1970. This report brings together most of the significant results of that research. Also discussed are the nature of appropriate calibration standards and the necessary conditions on the composition, size, and shape of the samples to allow accurate assays. Procedures for determining the correction for the sample self-attenuation are described at length including both general principles and several specific useful cases. The most useful concept is that knowing the linear attenuation coefficient of the sample (which can usually be determined) and the size and shape of the sample and its position relative to the detector permits the computation of the correction factor for the self-attenuation. A major objective of the report is to explain how the procedures for determining the self-attenuation correction factor can be applied so that calibration standards can be entirely appropriate without being particularly similar, either physically or chemically, to the items to be assayed. This permits minimization of the number of standards required to assay items with a wide range of size, shape, and chemical composition.
Download or read book Nuclear Safeguards Technology 1978 written by International Atomic Energy Agency and published by . This book was released on 1979 with total page 860 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transactions of the American Nuclear Society written by and published by . This book was released on 1987 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Standard Methods for the Examination of Water and Wastewater written by American Public Health Association and published by . This book was released on 1981 with total page 1254 pages. Available in PDF, EPUB and Kindle. Book excerpt:
