Track parameter of alpha particles with different energies in LR115 detector

LR115 (cellulose nitrate) solid state nuclear track detector (SSNTD) is widely used in the measurement of Radon (²²²Rn) and Thoron (²²⁰Rn) gas and it's decay products. In the present study, the effect of incident alpha particles of different energies on the track diameter registered in LR115 detector were analyzed. The exposure of LR115 detector to alpha particles incident leads to radiolytic scission of long polymer chains into shorter fragments and the production of reactive low molecular weight radiolytic products, which are more easily dissolved by etchant than the surrounding undamaged plastic during chemical analysis. This leads to a through and through etched track alongwith a slowly etching undamaged portion. The distance from the source, the residual energy reaching the LR115 detector and the median track diameter is given in the article. It was observed that alpha particle with energy 4.53 MeV and 0.89 MeV was not able to register the track in LR115 since it has an energy window of 1.5 to 4 MeV. It was observed that as the residual energy incident on the LR115 detector decreases the corresponding track diameter increases