Moveable Thermometer System in ProtoDUNE

TL;DR

This paper presents a movable 7-meter temperature profiler with 24 sensors for precise cryogenic temperature measurements in liquid-argon neutrino detectors, enabling improved calibration and monitoring of detector conditions.

Contribution

Introduction of a motorized, movable temperature profiler with in-situ cross-calibration capabilities for large liquid-argon detectors at CERN.

Findings

Achieved temperature measurement precision of a few millikelvin.

Demonstrated effective in-situ cross-calibration of sensors.

Provided detailed temperature profiles during ProtoDUNE operations.

Abstract

The movable temperature profiler is a 7 m vertical array of 24 sensors that measures cryogenic temperatures with a precision of a few mK. This precision is necessary to monitor the efficiency of re-circulation and purification of liquid-argon inside large liquid-argon based neutrino detectors. Liquid argon temperature impacts electron (signal) drift velocity, flow, purity distribution and thus the overall energy calibration. The temperature profiler is motorized and moves vertically, while in the detector, and cross-calibrates neighboring sensors. The temperature offsets between each sensor cancel the effects of electromagnetic noise. This poster reports on the temperature measurements and such in-situ cross-calibrations at ProtoDUNE (single phase) at CERN.