Means and method for calibrating a photon detector utilizing electron-photon coincidence

摘要

An arrangement for calibrating a photon detector particularly applicable for the ultra-violet (UV) and vacuum ultra-violet (VUV) regions is based on electron photon coincidence utilizing crossed electron beam-atom beam collisions. Atoms are excited by electrons which lose a known amount of energy and scatter with a known remaining energy, while the excited atoms emit photons of known radiation. Electrons of the known remaining energy scattered in a particular direction are separated from other electrons and are sensed and counted. Photons emitted in a direction related to the particular direction of scattered electrons are detected by a detector to serve as a standard. Each of the electrons is used to initiate the measurement of a time interval which terminal with the arrival of a photon exciting the photon detector. Only the number of time intervals related to the coincidence correlation and of electrons scattered in the particular direction with the known remaining energy and photons of a particular radiation level emitted due to the collisions of such scattered electrons are counted. The detectors calibration is related to the number of counted electrons and photons. Once calibrated the photon detector is useable to calibrate other photon detectors.