A method is described whereby VUV photon detectors can be accurately calibrated. This method is illustrated by taking the 58.4-nm transition of He as an example. The technique consists of crossing a monoenergetic electron beam with a beam of He atoms. When inelastically scattered electrons which have excited the 21P state are detected in coincidence with the 58.4-nm photons emitted in the decay of the excited state, the interaction volume formed by the crossed beams constitutes a standard source of photons. By comparing the number of detected coincidences with the predicted number the calibration can be made. A total detector efficiency of 0.024 ± 0.003 is obtained for a Galileo 4830 channeltron.
© 1983 Optical Society of America
R. McAdams and S. K. Srivastava, "Electron—photon coincidence technique for the absolute calibration of VUV detectors," Appl. Opt. 22, 1551-1554 (1983)