An Innovative Analog Circuit to Retrieve Energy Information From Signals of Deeply Saturated Preamplifiers Connected to Semiconductor Detectors

In nuclear spectroscopy by definition a distorted signal from a saturated pre-amplifier cannot contain the correct energy information, being this one directly related to the signal amplitude.In this work we propose an innovative technique to exploit the charge-conservation principle to extract highresolution energy information from a deeply saturated chargesensitive pre-amplifier connected to semiconductor detectors.The previously described "Fast-Reset" technique enables to reconstruct the energy information from a saturated preamplifier collecting the charge on the input node with a current generator and performing a time-over-threshold measurement.However it requires an off-line post processing of the acquired data.The proposed circuit, instead, requires no post processing thanks to a peculiar Time-to-Amplitude converter that integrates a baseline rejection circuit.In this way an extension of the pre-amplifier spectroscopic energy range of a factor 20 or more is possible, with the generation of a signal whose shape is optimized for direct acquisition with a pulse-height analyzer and no additional filtering.