Cerenkov radiation as a light source for the 2000ndash;620hyphen;Aring; spectral range

摘要

Spectral power density from Cerenkov radiation was measured in the vacuum ultraviolet from 2000 to 620 Aring;. The radiation was produced by passing a 500hyphen;MeV 1hyphen;mAhyphen;peakhyphen;current electron beam through 1.4 m of 1 atm of helium gas at room temperature. In the photon energy range from 6 to 20 eV, approximately 1014photons /sec/Aring;/mA of electronhyphen;beam current were emitted, and our detection apparatus attenuated the radiation by 4ndash;5 orders of magnitude.