LET as a Determinant of Oxygen Enhancement Ratio and Shape of Survival Curve forChlamydomonas

Abstract

Survival curves for Chlamydomonas were obtained for radiations having different values of LETα or stopping power. Irradiations were performed under either aerobic or anoxic conditions. Survival curves changed mostly in respect of extrapolation number or shoulder width, as LET was increased, the final slope remaining almost constant. The mode of variation in o.e.r. was strikingly similar to the pattern of variation in D_Q as LET was increased. A straight line relationship was shown to exist between D_Q value and o.e.r. when these values were computed for the same experiments at different values of LETα.