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Neutron thermalization in solids


Lathrop, Kaye Don (1962) Neutron thermalization in solids. Dissertation (Ph.D.), California Institute of Technology.


To describe neutron thermalization in solid media, two simplified models are formulated to describe the motions of atoms bound in solids. One atomic model postulates that the atoms of solids are linear, classical, randomly oriented, harmonic oscillators characterized by a single energy; and the other model postulates the same basic oscillator but permits a distribution of oscillator energies. With atom speed distributions derived from these models, energy exchange cross sections are evaluated analytically assuming a free particle neutron-atom interaction. With these energy exchange cross sections, integral equations are formulated describing thermalization of neutrons in infinite homogeneous media containing a 1/v absorber. The integral equations of both atomic models are solved numerically for the neutron density speed distribution. Numerical results for the single energy atomic oscillator of unit mass are compared with experimental results for neutron thermalization in zirconium hydride. Results for the averaged energy atomic oscillator of unit mass are compared with the neutron density calculated from the Wigner-Wilkins monatomic gas model. This comparison is made for three values of absorption. Numerical results for averaged energy atomic oscillators of masses 1, 2, 9, and 12 are examined to determine the effect of atomic mass upon the neutron density distribution.

Item Type:Thesis (Dissertation (Ph.D.))
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Mechanical Engineering
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Lurie, Harold
Thesis Committee:
  • Unknown, Unknown
Defense Date:1 January 1962
Record Number:CaltechETD:etd-12122005-162942
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:4963
Deposited By: Imported from ETD-db
Deposited On:12 Dec 2005
Last Modified:26 Dec 2012 03:13

Thesis Files

PDF (Lathrop_kd_1962.pdf) - Final Version
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