Emission gasionisierender Strahlung aus Elektronenlawinen

The emission of ionizing vacuum ultraviolet radiation by electron avalanches was studied. The radiation was detected and its coefficients of absorption were determined by means of a suitably subdivided ionization chamber; the radiation was emitted by a discharge in the homogeneous field of a parallel-plane gap, and maintained by external irradiation of the cathode. Thus it became feasible to determine the dependence of the intensity of emission on the ratioE/p, which controls the energy distribution of the electrons in the discharge. In addition, the emission of radiation from a cylindrical discharge was studied.Besides a description of the experimental techniques and the data evaluation procedures, the results of measurements in oxygen are given. For the two most prominent components of the radiation, the coefficients of absorption areμ=38 cm−1 andμ≈250 cm−1, and the intensitiesω/α (exciting collisions per ionizing collision) increase withE/p, reaching aboutω/α≈10−2 forE/p=500 V/Torr·cm. There is marked quenching of excited states by collisions, and the quenching pressures of 2.5 Torr and about 0.5 Torr, respectively, were taken into account when statingω/α.