Accession Number : AD0720695

Title :   The Measurement of Temperature Dependent Thermal Neutrons in Water Using a Crystal Detector.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CALIF

Personal Author(s) : Bennett,Robert Gordon

Report Date : DEC 1970

Pagination or Media Count : 121

Abstract : The research was concerned with the temperature dependence of thermal neutron flux. In view of the excellent neutron detection capability exhibited by the Lithium Iodide Europium enriched crystal this phosphor was utilized for the investigation. A miniature crystal (4mm x 4mm) and a flexible light pipe combination was used to determine the neutron spatial distribution as a function of temperature using a Pu-Be source in a light-water medium. A separate experimental investigation, with Indium foils and activation analysis, was used to determine the temperature dependence of thermal neutron flux under the same experimental conditions as the crystal. A theoretical analysis was also conducted using Two-Group theory to obtain an expression for thermal flux with spatial and temperature dependent parameters. The results of the research indicate that the thermal neutron flux is temperature dependent in the region investigated (77 degrees - 168 degrees F). The experimental results verify the increasing trend of flux magnitude with increasing temperature, as predicted by the Two-Group solution. (Author)

Descriptors :   (*NEUTRON TRANSPORT THEORY, THERMAL NEUTRONS), (*NEUTRON FLUX, MEASUREMENT), NEUTRON DETECTORS, CRYSTALS, NEUTRON SCATTERING, NEUTRON CROSS SECTIONS, CURVE FITTING, NEUTRON AGE, INTEGRALS, NUMERICAL INTEGRATION, STATISTICAL ANALYSIS, COMPUTER PROGRAMS, THESES

Subject Categories : Nuclear Instrumentation
      Fission Reactor Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE