Calibration of high voltages at the ppm level by the difference of [superscript 83m]Kr conversion electron lines at the KATRIN experiment
The neutrino mass experiment KATRIN requires a stability of 3 ppm for the retarding potential at − 18.6 kV of the main spectrometer. To monitor the stability, two custom-made ultra-precise high-voltage dividers were developed and built in cooperation with the German national metrology institute Physikalisch-Technische Bundesanstalt (PTB). Until now, regular absolute calibration of the voltage dividers required bringing the equipment to the specialised metrology laboratory. Here we present a new method based on measuring the energy difference of two [superscript 83m]Kr conversion electron lines with the KATRIN setup, which was demonstrated during KATRIN's commissioning measurements in July 2017. The measured scale factor M = 1972.449(10) of the high-voltage divider K35 is in agreement with the last PTB calibration 4 years ago. This result demonstrates the utility of the calibration method, as well as the long-term stability of the voltage divider. ; United States. Department of Energy (Grant DEFG02- 97ER41020) ; United States. Department of Energy (Grant DE-FG02-94ER40818) ; United States. Department of Energy (Grant DE-SC0004036) ; United States. Department of Energy (Grant DEFG02-97ER 41033) ; United States. Department of Energy (Grant DE-FG02-97ER41041) ; United States. Department of Energy (Grant DE-AC02-05CH11231) ; United States. Department of Energy (Grant DE-SC00 11091)
