Evaluation of Frequency-based Multiplexing of Silicon Photomultipliers for Safeguards Applications

Year
2018
Author(s)
David L. Chichester - Idaho National Laboratory
Marc Wonders - Pennsylvania State University
Marek Flaska - Pennsylvania State University
Abstract
Normal 0 false false false EN-US JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:\"Table Normal\"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:\"\"; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:Cambria; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin;} One of the main advantages silicon photomultipliers (SiPMs) possess over most traditional photomultiplier tubes (PMTs) is their relative compactness. This small form factor can allow the tiling of many SiPMs together into an array to produce a light sensor with position sensitivity on the order of millimeters. While this position sensitivity theoretically enables new detection systems to be conceived, in practice it comes with the difficulty of reading out many individual channels. The costs of acquiring data from each SiPM in an array individually can quickly make prohibitive the actual construction of detectors aiming to take advantage of SiPM arrays' inherent position sensitivity. Thus, multiplexing multiple SiPMs into a single readout channel is essential for SiPM array-based technology to become feasible. One possible method for multiplexing is to modulate pulses from SiPMs with sinusoids of different frequencies corresponding to different SiPMs to be analyzed upon data acquisition. This modulation should enable the use of a single readout channel for multiple SiPMs in an array. However, the effects of adding this modulation on the pulse may deteriorate some characteristics derivable from information in the SiPM pulse such as energy resolution and pulse shape discrimination capability and must be assessed. This work will investigate the effects of mixing sinusoids of different frequencies and amplitudes with SiPM output pulses on characteristics important to safeguards applications.