Process and device for determining the spatial distribution of electrons emerging from the surface of a radioactive body

A device for determining the spatial distribution of the electrons emerging from a surface of a radioactive body, comprising:

• a gas detector including at least one chamber with a pair of parallelly disposed electrodes and containing both a noble gas and a gas or vapor that emits photons between said electrodes, and means for applying a continuous high voltage between said electrodes, whereby a first electrode of said pair comprises means for receiving, against its external face, the surface of the radioactive body to be observed;
• a brilliance amplifier arranged for receiving the photons that are emitted by excited atoms which are produced in the vicinity of the other electrode of said pair by electron avalanches resulting from an electrical field between said electrodes produced by said continuous high voltage;
• a camera arranged behind the brilliance amplifier;
• and
• computing means capable of computing, in response to an output signal of the camera, entrance points in said gas detector, at the first electrode, of the electrons emerging from said surface of the radioactive body.