Quantum Efficiency Measurements of Dark Matter PMT

In this paper, improvements were made to procedure for measuring the quantum efficiency of dark matter photomultiplier tubes (PMTs), via LabVIEW automation software. Current dark matter detectors, such as the XENON100 experiment, as well as future detectors, such as the XENON1T, rely on the characterization of the component PMTs in order to properly analyze the data obtained during the course of the experiment. The quantum efficiency is, in general, a function of wavelength, and must be tested in order to determine the number of incident photons on the PMTs, that may be indicative of a dark matter signal. To allow for this process to be done more efficienctly, LabVIEW software was developed to allow for wavelength scans between 155 nm and 380 nm. This software was tested by performing several room temperature quantum efficiency scans. The results were in agreement with the manufacturers specifications and were self-consistent, indicating that the software performed properly. The applicability of the software to the quantum efficiency measurement experimental set-up will allow for measurements to be made more quickly, in present and future testing of PMTs, at both room temperature and low temperature.