RBE and OER Variations of Mixtures of Plutonium Alpha Particles and X-Rays for Damage to Human Kidney Cells (T-1)

Cell survival measurements using T-1 cells were made following exposure to several mixtures of high LET alpha particles from239 Pu with X rays under aerobic and hypoxic conditions. The results indicate that a small percentage of the total dose due to alpha particles was very effective in reducing the OER; however, the RBE does not increase appreciably. For example, when only 11% of the total dose was due to alpha particles, the OER was 1.8 compared to 2.5 for X rays, although the RBE was less than 1.2. These results are consistent with published results of OER and RBE measurements using fast neutrons and the a broadened Bragg peak of a helium ion beam.