Design and operation of LongBo: a 2 m long drift liquid argon TPC

TL;DR

This paper details the design and successful operation of LongBo, a 2-meter long liquid argon TPC with high electron lifetime and improved signal-to-noise ratio, demonstrating advancements in detector technology for particle physics.

Contribution

It introduces a novel 2-meter drift liquid argon TPC with integrated preamplifiers and reports on its performance metrics and electron lifetime measurements.

Findings

Electron drift lifetime of at least 14 ms at 95% confidence.

Signal-to-noise ratio of 30 for discrete channels at 350 V/cm.

ASIC preamplifiers achieved 1.4 times higher S/N ratio than discrete preamplifiers.

Abstract

In this paper, we report on the design and operation of the LongBo time projection chamber in the Liquid Argon Purity Demonstrator cryostat. This chamber features a 2 m long drift distance. We measure the electron drift lifetime in the liquid argon using cosmic ray muons and the lifetime is at least 14 ms at 95\% confidence level. LongBo is equipped with preamplifiers mounted on the detector in the liquid argon. Of the 144 channels, 128 channels were readout by preamplifiers made with discrete circuitry and 16 channels were readout by ASIC preamplifiers. For the discrete channels, we measure a signal-to-noise (S/N) ratio of 30 at a drift field of 350 V/cm. The measured S/N ratio for the ASIC channels was 1.4 times larger than that measured for the discrete channels.