The observation of neutrinoless double-beta decay would
provide evidence for the proposition that neutrinos are their own
antiparticle, a property that is not prescribed in the Standard
Model. The proposed Large Enriched Germanium Experiment
for Neutrinoless double beta Decay (LEGEND) will search for
this decay mode in 76Ge by deploying high-purity germanium
(HPGe) detectors enriched in this isotope. The signal from two
hundred kilograms of HPGe detectors will be fed to
low-radioactivity, charge-sensing amplifiers (CSA) deployed in
the first phase of the LEGEND experiment: LEGEND-200. We
optimized the performance of the CSA in different test
conditions by varying the operating parameters (including
voltages supplied to the active components of the CSA) and
measured the properties of the amplified waveform, such as rise
time, dynamic range, and electronic noise. The optimized
parameters lead to waveforms with the following characteristics:
90 ns rise time, a dynamic range from 0-10 MeV, and noise of
620 keV (FWHM) at a total power consumption of 156 mW in
liquid nitrogen. The optimization process will continue as the
circuit is integrated with other components of the experiment.