Preparation of Pure Plutonium Metal Standards for Nondestructive Assay.

Technical Information Center Oak Ridge Tennessee

关键词: Neutron counters;    Plutonium;    Nondestructive analysis;    Calibration;    Gamma radiation;   

RP-ID  :  PB2001103961

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

To calibrate neutron coincidence and neutron multiplicity counters for passive assay of plutonium, certain detector parameters must be determined. When one is using small plutonium metal samples, biases can be introduced from non-zero multiplication and impurities. This paper describes preparing small, pure plutonium metal standards with well-known geometries to enable accurate multiplication corrections and with acceptably low levels of impurities. To minimize multiplication, these standards are designed as 2-cm-diameter foils with varying thicknesses and masses of 1.4, 3.6, and 7.2 g plutonium. These standards will significantly improve characterization and calibration of neutron coincidence and multiplicity counters. They can also be equally useful for gamma-ray spectrometry and calorimetry. Five sets will be made: four for other United States Department of Energy plutonium facilities, and one set to remain at Los Alamos. We will also describe other nondestructive assay standards that are planned for the next few years.