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An array of twelve Compton-suppressed HPGe detectors


Annealing station

An oil free vacuum station based on turbo molecular pump and diaphragm pump is set up in the GDA laboratory for annealing and evacuating the cryostats of HPGe detectors. This system is protected against power failures with solenoid activated valve. This annealing system has become the work station for HPGe detector maintenance activities.

LN2 autofilling system

An automatic liquid nitrogen filling system has been designed and made in-house, with a dedicated controller which controls a set of electro-pneumatic valves/sensors to fill the 12 HPGe detectors in proper sequence and in failsafe mode. The temperature readout from the sensors (platinum resistor - PT100 whose resistance varies linearly with temperature) is communicated to the PC through the ADC in the controller. The controller also has the relays to operate the 24 V dc solenoids of electro-pneumatic valves.

The filling system consists of dedicated manifolds for liquid nitrogen and compressed air on both sides of the beamline each catering to 6 detectors. The detectors are periodically and automatically filled once a day. Fill log is maintained in a logfile for monitoring purposes. Filling is done from a 200 l capacity LN2 dewar (at a pressure of 22 psig) which itself gets filled from a 5000 l dewar kept outside the Beam Hall, once in 2 days. The process is controlled by a GUI code working in linux environment. The configuration of the number of detectors, sensors, valves (enabled/disabled) are kept in the file 'lnfill.conf'.

Contact us:
S. Muralithar
Inter University Accelerator Centre
Aruna Asaf Ali Marg, Post Box 10502
New Delhi 110067, India
Phone: +91 11 26893955
Telefax: +91 11 26893666
This page is maintained by S. Muralithar ( ). Last updated on January 23, 2012.