An improved design of the readout base board of the photomultiplier tube for future PandaX dark matter experiments

TL;DR

This paper introduces an improved readout base board for photomultiplier tubes in PandaX dark matter experiments, significantly enhancing dynamic range to better detect signals across a wider energy spectrum.

Contribution

The paper presents a novel design of the PMT readout base board that extends the dynamic range, addressing saturation issues at high energies in PandaX experiments.

Findings

Enhanced dynamic range of PMT readout board

Reduced signal saturation at MeV energies

Improved detection sensitivity for high-energy signals

Abstract

The PandaX project consists of a series of xenon-based experiments that are used to search for dark matter (DM) particles and to study the fundamental properties of neutrinos. The next DM experiment PandaX-4T will be using 4 ton liquid xenon in the sensitive volume, which is nearly a factor of seven larger than that of the previous experiment PandaX-II. Due to the increasing target mass, the sensitivity of searching for both DM and neutrinoless double-beta decay ($0\nu\beta\beta$) signals in the same detector will be significantly improved. However, the typical energy of interest for $0\nu\beta\beta$ signals is at the MeV scale, which is much higher than that of most popular DM signals. In the baseline readout scheme of the photomultiplier tubes (PMTs), the dynamic range is very limited. Signals from the majority of PMTs in the top array of the detector are heavily saturated at MeV energies. This deteriorates the $0\nu\beta\beta$ search sensitivity. In this paper we report a new design of the readout base board of the PMTs for future PandaX DM experiments and present its improved performance on the dynamic range.