  Sufficient current pulse information of nuclear radiation detectors can be
retained by direct waveform digitization owing to the improvement of
digitizer's performance. In many circumstances, reasonable cost and power
consumption are on demand while the energy resolution and PSD performance
should be ensured simultaneously for detectors. This paper will quantitatively
analyse the influence of vertical resolution and sampling rate of digitizers on
the energy resolution and PSD performance. The energy resolution and PSD
performance can be generally optimized by improving the sampling rate and ENOB
(effective number of bits) of digitizers. Several integrated digitizers, with
sampling rates varying from 100 MSPS to 500 MSPS and vertical resolution
ranging from 12-Bit to 16-Bit, were designed and integrated with a CLYC
detector for verifications. Experimental results show good accordance with
theoretical calculations. The conclusion can give guidance to designs of
digitizes for similar applications in need of optimizing the energy resolution
and PSD performance, and help to choose proper digitizers for different
requirements.
