Measurement of the two-photon absorption cross-section of liquid argon with a time projection chamber

TL;DR

This study measures the two-photon absorption cross-section of liquid argon using a time projection chamber, providing a new calibration tool for large-scale liquid argon detectors in particle physics.

Contribution

It introduces a novel method to accurately measure the two-photon absorption cross-section of liquid argon with a specialized TPC setup.

Findings

Measured sigma_ex = (1.24 ± 0.10_stat ± 0.30_syst) × 10^{-56} cm^4s^{-1}

Demonstrated the use of laser-induced ionization for detector calibration

Provided data to improve understanding of liquid argon optical properties

Abstract

This paper reports on laser-induced multiphoton ionization at 266 nm of liquid argon in a time projection chamber (LAr TPC) detector. The electron signal produced by the laser beam is a formidable tool for the calibration and monitoring of next-generation large-mass LAr TPCs. The detector that we designed and tested allowed us to measure the two-photon absorption cross-section of LAr with unprecedented accuracy and precision: sigma_ex=(1.24\pm 0.10stat \pm 0.30syst) 10^{-56} cm^4s{-1}.