SUBJECT: M.S. Thesis Presentation
BY: Ryan Bechtel
TIME: Thursday, June 8, 2006, 2:00 p.m.
PLACE: Neely Building, 118
TITLE: Uranium-232 Beryllide Neutron Source
COMMITTEE: Dr. Nolan Hertel, Chair (NRE)
Dr. Chris Wang (NRE)
Dr. Daniel Tedder (ChBE)


In this thesis the history and technical details of isotopic (a,n) neutrons sources are discussed. The use of U-232 as part of dirty uranium was proposed as a new isotope for use in beryllium (a,n) neutron sources. A [U-232]UBe13 neutron source was designed and modeled and the fluence and flux distributions were calculated. The U-232 decay chain emits six high energy alpha particles in quick succession and is ideal for use in a beryllium (a,n) neutron source. U-232 is an undesirable byproduct in the production of U-233 in the thorium fuel cycle; its concentrations can vary from 5-3000 ppm in bred U-233. A 1.1018-cm diameter by 1.1018-cm tall cylinder of [U-233]UBe13 with 300ppm U-232 at 0.74 GBq (20 mCi) was modeled and found to have a peak yield of 3.5*(10^5) n/s after 10.17 years. At this peak yield, the [U-232]UBe13 source has better neutron production efficiency per initial alpha emission activity than other beryllide neutron sources.