design and construction of a high precision tac

tac (time to amplitude convertor) is one of the most important time measurement instrumentswhich has great significance in many fields of science, especially radiation physics. a tac unit has beendesigned based on the start-stop analog method and nim (nuclear instrument modules) standards. afterdesigning the circuit, it was simulated by pspice software and constructed by discrete and integratedcomponents. accuracy of performance, linearity and time resolution of the tac were checked in laboratorycondition and a neutron-gamma discrimination experiment was carried out using this tac. results of theseexperiments and the spectrum of neutron-gamma discrimination completely agree with those from othersimilar tacs, and are, to some extent, better.