Investigation of Light Emission by Electron Avalanches in Binary Mixtures Where Xenon is the Parent Constituent. Attempted Interpretation of the Visible Continuum Emitted by Xenon

The field of use of gas detectors has been considerably extended through the addition of a third electrode in a parallel plane geometry. Apart from the possibility of obtaining spectrometric performances, pictures of objects emitting an X radiation may be obtained. Detection efficiency can be important when the filling gas is xenon which has a high atomic number. A polyatomic vapour must be added to ensure great electronic amplification. The localization data is provided either by a spark or by an electron avalanche. In this study we were interested in the light accompanying the electron avalanche. In this proportional mode, two kinds of information are available (a) the energy information given by the number of electrons of the avalanche head and (b) the spatial information from the light emitted during the avalanche. A coincidence measurement was made between the electric information constituted by the electrons of the avalanche head and the light information coming from the output slit of a grating monochromator. Coincidence information, which varies numerically in proportion to the number of avalanches per second, is sent to a recorder whose speed is co-related with the rotation speed of the grating. Minute by minute automatic zero reset of the recording enables a picture to be obtained by means of wave length intervals whose width is governed by the rotation speed of the grating.