Système de mesure de l'énergie d'électrons rétrodiffusés en fonction de l'angle d'émission

We present in this paper an experimental device for determining for an electron beam incident normal to a target, the angular and energetic backscattered electron distribution as a function of the emission angle. We use as detector a semiconductor diode cooled to a temperature of 100 K by liquid nitrogen. This detector can be moved around the target. The first results show that this device enables us to obtain the energy spectrum of electrons backscattered at different angles to the incident beam axis. From these measurements we have calculated the total angular and energy distributions ; the result is in good agreement with those obtained by other authors.