The Electronics, Trigger and Data Acquisition System for the Liquid Argon Time Projection Chamber of the DarkSide-50 Search for Dark Matter

TL;DR

This paper details the design and implementation of the electronics, trigger, and data acquisition systems for the DarkSide-50 liquid argon dark matter detector, enabling precise detection and recording of rare particle interactions.

Contribution

It introduces a custom electronics and data acquisition system optimized for low-background liquid argon TPC dark matter searches, operational since 2014.

Findings

Reliable detection of scintillation signals from argon interactions

Effective event triggering and data recording system

Operational since early 2014 with stable performance

Abstract

The DarkSide-50 experiment at the Laboratori Nazionali del Gran Sasso is a search for dark matter using a dual phase time projection chamber with 50 kg of low radioactivity argon as target. Light signals from interactions in the argon are detected by a system of 38 photo-multiplier tubes (PMTs), 19 above and 19 below the TPC volume inside the argon cryostat. We describe the electronics which processes the signals from the photo-multipliers, the trigger system which identifies events of interest, and the data-acquisition system which records the data for further analysis. The electronics include resistive voltage dividers on the PMTs, custom pre-amplifiers mounted directly on the PMT voltage dividers in the liquid argon, and custom amplifier/discriminators (at room temperature). After amplification, the PMT signals are digitized in CAEN waveform digitizers, and CAEN logic modules are used to construct the trigger, the data acquisition system for the TPC is based on the Fermilab "artdaq" software. The system has been in operation since early 2014.