The Application for Express Evaluation of Alpha Parameter in Plutonium Materials

Year
2004
Author(s)
A. V. Mozhayev - Pacific Northwest National Laboratory
Valery I. Bulanenko - Institute of Physics and Power Engineering
Abstract
It is useful when processing the results of neutron measurements to be able to assess the value of the alpha parameter (ratio of neutron production rate due to (a, n) reaction to that due to spontaneous fission) in a sample. This application was developed for the express evaluation of the alpha parameter for plutonium-bearing materials based on the isotopic composition of plutonium and the elemental content of the compound. The application exploits a traditional approach using Ziegler’s coefficients to calculate alpha particle stopping powers. However, the application uses weight instead of atomic values as input data for elemental content. This allows the user to easily evaluate the parameter for any material (both pure “theoretical” compound and real one containing various impurities). A practical advantage is that a user needs to know weight content of elements (as a normal practice) and not chemical formulae for all components of a compound. Some results of comparison between the Alpha Parameter application and the well known code Sources4A are presented. The application was verified and validated by PNNL for its usage in NDA projects. Alpha parameter is freeware and available on request from authors.