M.S. Thesis Presentation by Carla Ann White
Fall Semester 2000

(Dr. Chris Wang, advisor)

"Design of A252 Cf-based Irradiation Facility for radiobiological Experiments for 10B-enhanced 252Cf Brachytherapy"

Abstract

Ga Tech is currently conducting research in 10B-enhanced 252Cf Brachytherapy for cancer treatment. One major effort is to develop a well-collimated 252Cf neutron beam which can be used to preferentially irradiate a body part (e.g. the brain) of small animals (rats) and to irradiate cultured cells to determine the enhanced cell-killing effect due to the 10B(n, a)7Li reactions. The purpose of this study is to obtain the optimal configuration for the 252Cf irradiation facility to accommodate the rat and cell-culture experiments. The design criteria for a neutron collimator to irradiate a 1-cm diameter spherical rat brain are to obtain: a high total neutron dose rate to the brain, a high thermal-to-total neutron dose ratio, a high brain-to-body neutron dose ratio (³10). The design criteria for irradiation of the test-tube cell cultures are to obtain: a high total neutron dose rate and a high thermal-to-total neutron dose ratio while being able to vary these to determine the cell survival curve. The moderator of the text-tube cell culture must accommodate several test-tubes at a time at different distances from the source to vary the total neutron dose to the cell culture. Materials to be considered as moderator and collimator are water, deuterium, polyethylene, borated polyethylene, FLUENTAL, beryllium, and beryllia. The Monte Carlo neutron transport code MCNP-4B will be used to determine the best geometry, materials and their thicknesses for the experiment neutron beam moderator/collimator.