Characterization and calibration of a SSNTD for heavy-ion detection and strangelet search in cosmic rays

A commercially available grade of polymer was investigated for its suitability as a solid state nuclear track detector (SSNTD) to look for rare events in cosmic rays at very high mountain altitudes. It was identified to be polyethylene terephthalate (PET) and found to have a higher detection threshold compared to many other widely used SSNTDs. Hence it is particularly suited for rare event search in cosmic rays by eliminating the dominant low Z background. Systematic studies were carried out to determine the ideal etching condition. Also the charge response of PET was studied using various ion beams from accelerators. The results of such studies were combined to obtain the calibration curve for PET as SSNTD, by which one can identify and characterize charged particles.