# The XENON1T Data Acquisition System

## TL;DR

The XENON1T data acquisition system is a highly sensitive, low-threshold, and high-bandwidth setup that efficiently digitizes and stores signals from the detector, enabling three years of successful operation in dark matter research.

## Contribution

This paper presents a novel DAQ system combining commercial, open source, and custom components with advanced trigger and database techniques for high-efficiency detection in dark matter experiments.

## Key findings

- Achieved sub-0.1 photoelectron threshold
- Over 97% event recognition efficiency
- Supported over 300 MB/s bandwidth during calibration

## Abstract

The XENON1T liquid xenon time projection chamber is the most sensitive detector built to date for the measurement of direct interactions of weakly interacting massive particles with normal matter. The data acquisition system (DAQ) is constructed from commercial, open source, and custom components to digitize signals from the detector and store them for later analysis. The system achieves an extremely low signal threshold below a tenth of a photoelectron using a parallelized readout with the global trigger deferred to a later, software stage. The event identification is based on MongoDB database queries and has over 97% efficiency at recognizing interactions at the analysis energy threshold. A readout bandwidth over 300 MB/s is reached in calibration modes and is further expandable via parallelization. This DAQ system was successfully used during three years of operation of XENON1T.