Measurement of the absolute Quantum Efficiency of Hamamatsu model R11410-10 photomultiplier tubes at low temperatures down to liquid xenon boiling point

摘要

We report on the measurements of the absolute Quantum Efficiency(QE) forHamamatsu model R11410-10 PMTs specially designed for the use in low backgroundliquid xenon detectors. QE was measured for five PMTs in a spectral rangebetween 154.5 nm to 400 nm at low temperatures down to -110$^0$C. It was shownthat during the PMT cooldown from room temperature to -110 $^0$C (a typical PMToperation temperature in liquid xenon detectors), the absolute QE increases bya factor of 1.1 - 1.15 at 175 nm. The QE growth rate with respect totemperature is wavelength dependent peaking at about 165 nm corresponding tothe fastest growth of about -0.07 %QE/$^{0}C$ and at about 200 nm correspondingto slowest growth of below -0.01 %QE/$^{0}C$. A dedicated setup and methods forPMT Quantum Efficiency measurement at low temperatures are described indetails.