Thesis Defense: Design, Characterization, and Simulation of a Cryogenic Irradiation Facility in the Ohio State University Research Reactor Pool

Committee:

• Dr. Thomas Blue
• Dr. Tunc Aldemir

Abstract:

The Cryogenic Irradiation Facility (CRIF) has been designed and constructed for use in the OSU Research Reactor (OSURR) Pool. The CRIF will allow for experiments to be completed in situ on optical and electronic materials, from liquid helium temperatures to above room temperatures in the mixed radiation field of the OSURR. The CRIF will allow researchers to understand the combined effects of high radiation fields at cryogenic temperatures. The CRIF will also allow researchers to control temperature after an irradiation, to understand the effects of low temperature annealing. The CRIF will be used in a unique 10" Dry Tube facility which will be adjacent to the OSURR core. The 10" Dry Tube and the CRIF have been simulated in MCNP6, to predict the radiation fields in the empty 10" Dry Tube and in representative materials (both optical fibers and GaN transistors) inside the geometry of the CRIF in the 10" Dry Tube. These models have been analyzed to understand the amount of total radiation energy deposition that will occur, to predict the time to boil-off of the liquid helium in the CRIF, which provides estimations of experimental design parameters for irradiation time and power. It has been predicted that the CRIF can operate for two hours at a time before liquid helium boil-off, and a requisite liquid helium refill, at a reactor power level of 50 kW and a corresponding neutron fast flux of 4.05*10¹⁰ neutrons/(cm²-s).