High resolution nuclear timing spectroscopy system based on new method of free running ramp and tracking ADCs

Abstract

The paper describes a new method for high resolution nuclear timing spectroscopy system using tracking ADCs and free running ramp to give the timing resolution of few ps over wide dynamic range of time interval extending up to few µs. The method makes use of tracking ADCs with 16 bit resolution with low conversion time of nearly 1 µs along with a free running ramp which is given as input to the two ADCs. Both the ADCs and ramp are designed to track their characteristics in order to neutralize the errors due to drift in their characteristics and hence complex system of spectrum stabilization is not required. ADC1 digitizes ramp input at the arrival of START pulse and ADC2 digitizes ramp input at the arrival of STOP pulse. The difference between digital codes of these ADCs is a measure of time interval between START and STOP pulses. New system doesn’t require delay and hence biased amplifier. System has dead time of 1 µs and spectrum stabilization is easy.