B. Schlitzer | Searcharxiv

arXiv2021

Characterization of the scintillation time response of liquid argon detectors for dark matter search

The scintillation time response of liquid argon has a key role in the discrimination of electronic backgrounds in dark matter search experiments. However, its extraordinary rejection power can be affected by various detector effects such as the delayed light emission of TetraPhenyl Butadiene, the most commonly used wavelength shifter, and the electric drift field applied in Time Projection Chambers. In this work, we characterized the TetraPhenyl Butadiene delayed response and the dependence of the pulse shape discrimination on the electric field, exploiting the data acquired with the ARIS, a small-scale single-phase liquid argon detector exposed to monochromatic neutron and gamma sources at the ALTO facility of IJC Lab in Orsay.

physics.ins-det↗

arXiv2018

Measurement of the liquid argon energy response to nuclear and electronic recoils

A liquid argon time projection chamber, constructed for the Argon Response to Ionization and Scintillation (ARIS) experiment, has been exposed to the highly collimated and quasi-monoenergetic LICORNE neutron beam at the Institute de Physique Nuclaire Orsay in order to study the scintillation response to nuclear and electronic recoils. An array of liquid scintillator detectors, arranged around the apparatus, tag scattered neutrons and select nuclear recoil energies in the [7, 120] keV energy range. The relative scintillation efficiency of nuclear recoils was measured to high precision at null field, and the ion-electron recombination probability was extracted for a range of applied electric fields. Single Compton scattered electrons, produced by gammas emitted from the de-excitation of $^7$Li* in coincidence with the beam pulse, along with calibration gamma sources, are used to extract the recombination probability as a function of energy and electron drift field. The ARIS results have been compared with three recombination probability parameterizations (Thomas-Imel, Doke-Birks, and PARIS), allowing for the definition of a fully comprehensive model of the liquid argon response to nuclear and electronic recoils down to a few keV range. The constraints provided by ARIS to the liquid argon response at low energy allow the reduction of systematics affecting the sensitivity of dark matter search experiments based on liquid argon

physics.ins-det↗