Response of Bacillus Subtilis Spores to Heavy Ion Irradiation Using Cellulose Nitrate Detectors

摘要

Cellulose nitrate sheets carrying the spores of Bacillus subtilis were irradiated with accelerated iron ions under Biostack conditions. The initial energy on the top of the stack was 250 MeV/n with a fluence of 1,000-10,000 particles/sq cm. The energy of the particles for evaluation within the stack varied from 100 MeV/n to 150MeV/n. A second experiment was performed using argon ions and an energy of 1.4 MeV/n. The spores were incubated directly on the surface of the detector foil, and the outgrowth of individual spores around one single track was observed after different incubation times and was documented by microphotography. For values below 1 micron, a steep decrease of K prime was observed. At higher impact parameters, K prime exceeds the control level in two regions around 1.3 microns and 3 microns with regions of average control survival in between.