Facilities

To reduce noise level and hence to increase energy resolution of silicon surface barrier detectors, cooling provision is provided with the brass detector holders. The Freon cooling arrangement, with coolant feedthrough on one of the back ports of the chamber, can bring detector temperature down up to -4^o C for six detectors in half an hour. A warming up facility is installed along with the detector cooling system, once the timing performance is tested out. Warming up time for the detectors from -4^o C to 20^o C is about 20 minutes.

Particle-gamma correlation studies require the gamma detector to be placed quite close to the target to have better count rates. We have vacuum compatible gamma detector cups to have access inside the chamber at 90^o and 30^o. Detectors with diameter upto 23 cm can be placed at a distance of 29 cm from the target, while detectors with diameter upto 8 cm can be placed at a distance of 9 cm from the target. Detectors with diameter upto 5 cm can be mounted from the top.

Different types of gas detectors like ionization chambers, parallel plate avalanche counters (PPAC), multi wire proportional counters (MWPC) etc. are used in GPSC for nuclear physics as well as materials science experiments. A flange with gas feedthrough is mounted at a back angle port. The gas flow control system is made in such a way that it can handle different gas pressure regions according to the requirement.

This versatile facility which consists of a feedthrough, a transfer body and an intermediate body has multipurpose usage. Within a time lapse of about 20 minutes, one target ladder can be replaced with another with very little disturbance in the chamber vacuum (chamber vacuum changes from low 10^-6 mbar to low 10^-5 mbar).