Position sensitive silicon semiconductor detector for measurement of cosmic ray isotopes

In order to separate high energy cosmic ray isotopes, a silicon ΔE-E telescope was developed. In particular, the large-area position sensitive silicon detector is necessary to measure accurately the incident angle of cosmic ray isotopes. The diameter and thickness of the silicon detector used are 70 mm and 1.5 mm, respectively. The detector is capable of separating 12C and 13C with energy of about 100 MeV/nucl. 187 MeV 12C ions from a heavy ion accelerator were used to measure the position-resolving power. The position resolution was 1.2 mm (FWHM). The present data indicate that 12C and 13C isotopes can be separated enough with this position sensitive silicon detector telescope. (Yoshimori, M.)