The Determination of Thermal Neutron Density from the Absolute Measurement of the Activity Induced in Gold Foils

Author

Munson M. Thorpe

Publication Date

6-5-1962

Abstract

The interaction of thermal neutrons with a coin shaped detector is discussed in terms of the reaction rate in an infinite sheet of pure absorber irradiated in a void by an isotropic, Maxwell distribution of thermal neutrons. A coincidence method for the evaluation of the decay rate of the neutron induced activity in gold is examined in detail and utilized to measure the relative specific activity of gold foils exposed to neutrons in the graphite thermal column of the Water Boiler Reactor. The relative specific activity was obtained for 3/4" and 1/4" diameter foils as a function of thickness for values of the thickness from 1.5 mg/cm² to a nominal thickness of .010". From the activity of the thinnest foils, the neutron density in the thermal column was obtained relative to the reactor power and the counting rate of a parallel plate fission chamber.

Degree Name

Physics

Level of Degree

Masters

Department Name

Physics & Astronomy

First Committee Member (Chair)

Christopher Pratt Leavitt

Second Committee Member

Howard Carnes Bryant

Third Committee Member

Donald E. Skabelund

Language

English

Document Type

Thesis

Recommended Citation

Thorpe, Munson M.. "The Determination of Thermal Neutron Density from the Absolute Measurement of the Activity Induced in Gold Foils." (1962). https://digitalrepository.unm.edu/phyc_etds/171