A computer-programmable delay-generator scheme for the TACTIC gamma-ray telescope

A programmable multi-channel digital-delay generator, characterised by negligible dead-time count losses, has been developed for deployment in the high-sensitivity TeV γ-ray telescope, TACTIC. This telescope comprises an array of 4x10 m2 of light collectors, of which three are placed at the corners of an equilateral triangle of side ≥20 m and are operated in a prompt-coincidence mode with a resolving time of similar 10 ns to detect atmospheric Cherenkov events produced by very high energy γ-ray and cosmic-ray proton primaries. The delay generator helps to line up these events in real time whenever they are detected at different relative times by these elements. The basic circuit used in this scheme can be readily adapted for utilisation in several other areas, including experimental nuclear physics. ((orig.))