Determination of high LET cosmic particles' trajectories for space radiobiological studies

During IML-1 mission, we carried out space experiments on radiobiological effect of a single HZE cosmic particle. In the experiment, the precise determination of the distance between the center of the particle trajectory and the individual biological objects around it is an indispensable condition. For the detection of HZE particles CR-39 track detectors were used and analyzed by the video image processing. The positions of biological objects in relation to a particle trajectory were measured by referring to the laser grid marks which were printed on the surface of CR-39 detector. We describe such an experimental method and report the applicability of this method.