Angular dependent measurement of electron-ion recombination in liquid argon for ionization calorimetry in the ICARUS liquid argon time projection chamber

TL;DR

This study investigates how electron-ion recombination in liquid argon varies with the angle of ionizing tracks in the ICARUS TPC, improving energy calibration and particle identification accuracy.

Contribution

It introduces an angular-dependent model of recombination (EMB) that enhances the calibration and measurement precision in liquid argon TPCs.

Findings

Recombination depends on the track angle relative to the electric field.

The EMB model accurately describes recombination across all measured angles.

Accounting for angular dependence improves energy measurement accuracy.

Abstract

This paper reports on a measurement of electron-ion recombination in liquid argon in the ICARUS liquid argon time projection chamber (LArTPC). A clear dependence of recombination on the angle of the ionizing particle track relative to the drift electric field is observed. An ellipsoid modified box (EMB) model of recombination describes the data across all measured angles. These measurements are used for the calorimetric energy scale calibration of the ICARUS TPC, which is also presented. The impact of the EMB model is studied on calorimetric particle identification, as well as muon and proton energy measurements. Accounting for the angular dependence in EMB recombination improves the accuracy and precision of these measurements.