Performance of Linear Classification Algorithms on alpha/gamma Discrimination for LaBr3:Ce Scintillation Detectors with Various Pulse Digitizer Properties

• Main Authors: Wen, Jingjun, Zhu, Jinfu, Xue, Tao, Cang, Jirong, Wei, Liangjun, Nie, Qiyuan, Zeng, Ming, Zeng, Zhi, Ma, Hao, Li, Jianmin, Liu, Yinong
• Format: Journal Article
• Language: English
• Published: 03-02-2020
• Subjects: Physics - High Energy Physics - Experiment; Physics - Instrumentation and Detectors
• DOI: 10.48550/arxiv.2002.00570

With the development of high-speed readout electronics, the digital pulse
shape discrimination (PSD) methods have attracted the attention of more
researchers, especially in the field of high energy physics and neutron
detection. How to choose a PSD algorithm and corresponding data acquisition
system (DAQ) naturally becomes a critical problem to settle down for the
detection system designers. In this paper, the relationship between the
classification performance of different PSD algorithms and digitizers' sampling
properties (including sampling rate and the effective number of bits) has been
researched based on $\mathrm{LaBr_3}$:Ce scintillation detectors. A
self-developed integrated digitizer configured with five different ADCs and a
WavePro 404HD oscilloscope were deployed to digitize the waveforms from
$\mathrm{LaBr_3}$:Ce scintillators. Moreover, three PSD methods, charge
comparison method (CCM), least square for classification method (LS) and
Fisher's linear discriminant analysis (LDA), based on linear model were applied
to discriminate the alpha signals from the intrinsic isotope $^{227}$Ac. With
the LS method and a 125 MSPS 14-Bit ADC, the FoM value was 1.424$\pm$0.042,
which is similar to the result from LDA but 31\% better than the result of CCM.
The discrimination results showed that the performances of LS and LDA are less
affected by the sampling rate with respect to the CCM method, which reflects in
a better PSD capability. The results of this paper can help the developers of
detector systems to make a trade-off among sampling properties, desirable
discrimination results and the cost of systems.