  Fast digitisers and digital pulse processing have been widely used for
spectral application and pulse shape discrimination (PSD) owing to their
advantages in terms of compactness, higher trigger rates, offline analysis,
etc. Meanwhile, the noise of readout electronics is usually trivial for
organic, plastic, or liquid scintillator with PSD ability because of their poor
intrinsic energy resolution. However, LaBr3(Ce) has been widely used for its
excellent energy resolution and has been proven to have PSD ability for
alpha/gamma particles. Therefore, designing a digital acquisition system for
such scintillators as LaBr3(Ce) with both optimal energy resolution and
promising PSD ability is worthwhile. Several experimental research studies
about the choice of digitiser properties for liquid scintillators have already
been conducted in terms of the sampling rate and vertical resolution.
Quantitative analysis on the influence of waveform digitisers, that is, fast
amplifier (optional), sampling rates, and vertical resolution, on both
applications is still lacking. The present paper provides quantitative analysis
of these factors and, hence, general rules about the optimal design of
digitisers for both energy resolution and PSD application according to the
noise analysis of time-variant gated charge integration.
