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Free keywords:
Physics, Instrumentation and Detectors, physics.ins-det, Physics, Data Analysis, Statistics and Probability, physics.data-an
MPINP:
LHCb - Abteilung Hofmann
Abstract:
This paper describes state-of-the-art digital filtering techniques that are
part of GEANA, an automatic data analysis software used for the GERDA
experiment. The discussed filters include a novel, nonlinear correction method
for ballistic deficits, which is combined with one of three shaping filters: a
pseudo-Gaussian, a modified trapezoidal, or a modified cusp filter. The
performance of the filters is demonstrated with a 762 g Broad Energy Germanium
(BEGe) detector, produced by Canberra, that measures {\gamma}-ray lines from
radioactive sources in an energy range between 59.5 and 2614.5 keV. At 1332.5
keV, together with the ballistic deficit correction method, all filters produce
a comparable energy resolution of ~1.61 keV FWHM. This value is superior to
those measured by the manufacturer and those found in publications with
detectors of a similar design and mass. At 59.5 keV, the modified cusp filter
without a ballistic deficit correction produced the best result, with an energy
resolution of 0.46 keV. It is observed that the loss in resolution by using a
constant shaping time over the entire energy range is small when using the
ballistic deficit correction method.
