The proton response of the TS-16 type of CR-39 plastic nuclear track detector has been studied with accelerated and fast neutron induced protons in vacuum and in air. The diameters of etched tracks were measured as a function of etching time and the etch rate ratio and the etch induction layer were determined from the growth curve of the diameter using a variable etch rate ratio model. In the case of the accelerated protons in vacuum an anomalous incident angle dependence of the response is observed.
The CR-39 track detectors have been applied to irradiate the Chinese hamster V79-753B cells for survival studies. The survival curves have given satisfactory results. Energies of the incoming as well as outgoing proton beams evaluated from the track diameters are found to be close to the values found separately by surface barrier detector (SSBD).
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.
ABSTRACT The absence of excesses of fission tracks along the boundaries between olivine crystals and metal grains indicates that the concentration of fissioning superheavy elements in the metal must have been less than about 2.5 × 10−15 kg kg−1 and 2.5 × 10−13 kg kg−1 in the chondritic meteorites Wold Cottage and Alta'ameem respectively. The abundance of 244Pu fission tracks in phosphates from each meteorite suggests that track retention could not have commenced later than about 4 × 109 y ago. Superheavy element concentrations of such magnitudes would not provide a sufficient heat source to drive a lunar core dynamo.
ABSTRACT In order to get significant results in momentum and angular correlation analysis of particles inside jets at very high energy a new charged particles detector has been developped and tested. Preliminary comments and results are presented.
