You need JavaScript to view this

Measurement of the Time Dependence of Neutron Slowing-Down and Therma in Heavy Water

Abstract

The behaviour of neutrons during their slowing-down and thermalization in heavy water has been followed on the time scale by measurements of the time-dependent rate of reaction between the flux and the three spectrum indicators indium, cadmium and gadolinium. The space dependence of the reaction rate curves has also been studied. The time-dependent density at 1.46 eV is well reproduced by a function, given by von Dardel, and a time for the maximum density of 7.1 {+-} 0.3 {mu}s has been obtained for this energy in deuterium gas in agreement with the theoretical value of 7.2 {mu}s. The spatial variation of this time is in accord with the calculations by Claesson. The slowing- down time to 0.2 eV has been found to be 16.3 {+-}2.4 {mu}s. The approach to the equilibrium spectrum takes place with a time constant of 33 {+-}4 {mu}s, and the equilibrium has been established after about 200 {mu}s. Comparison of the measured curves for cadmium and gadolinium with multigroup calculations of the time-dependent flux and reaction rate show the superiority of the scattering models for heavy water of Butler and of Brown and St. John over the mass 2 gas model. The experiment has been supplemented  More>>
Authors:
Publication Date:
Mar 15, 1966
Product Type:
Technical Report
Report Number:
AE-216
Resource Relation:
Other Information: 32 refs., 8 figs., 2 tabs.
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; SLOWING-DOWN; HEAVY WATER; NEUTRONS; SPATIAL DISTRIBUTION; TIME DEPENDENCE; INDIUM; GADOLINIUM; CADMIUM
OSTI ID:
20949521
Research Organizations:
AB Atomenergi, Nykoeping (Sweden)
Country of Origin:
Sweden
Language:
English
Other Identifying Numbers:
TRN: SE0708496
Availability:
Commercial reproduction prohibited; OSTI as DE20949521
Submitting Site:
SWDN
Size:
38 pages
Announcement Date:
Dec 17, 2007

Citation Formats

Moeller, E. Measurement of the Time Dependence of Neutron Slowing-Down and Therma in Heavy Water. Sweden: N. p., 1966. Web.
Moeller, E. Measurement of the Time Dependence of Neutron Slowing-Down and Therma in Heavy Water. Sweden.
Moeller, E. 1966. "Measurement of the Time Dependence of Neutron Slowing-Down and Therma in Heavy Water." Sweden.
@misc{etde_20949521,
title = {Measurement of the Time Dependence of Neutron Slowing-Down and Therma in Heavy Water}
author = {Moeller, E}
abstractNote = {The behaviour of neutrons during their slowing-down and thermalization in heavy water has been followed on the time scale by measurements of the time-dependent rate of reaction between the flux and the three spectrum indicators indium, cadmium and gadolinium. The space dependence of the reaction rate curves has also been studied. The time-dependent density at 1.46 eV is well reproduced by a function, given by von Dardel, and a time for the maximum density of 7.1 {+-} 0.3 {mu}s has been obtained for this energy in deuterium gas in agreement with the theoretical value of 7.2 {mu}s. The spatial variation of this time is in accord with the calculations by Claesson. The slowing- down time to 0.2 eV has been found to be 16.3 {+-}2.4 {mu}s. The approach to the equilibrium spectrum takes place with a time constant of 33 {+-}4 {mu}s, and the equilibrium has been established after about 200 {mu}s. Comparison of the measured curves for cadmium and gadolinium with multigroup calculations of the time-dependent flux and reaction rate show the superiority of the scattering models for heavy water of Butler and of Brown and St. John over the mass 2 gas model. The experiment has been supplemented with Monte Carlo calculations of the slowing down time.}
place = {Sweden}
year = {1966}
month = {Mar}
}