SPECTROMETER FOR MEASURING THE SPECTRA OF THE CHARACTERISTIC ENERGY LOSSES OF FAST ELECTRONS IN THIN METAL FOILS.

A spectrometer is described that is used to measure the characteristic energy losses of fast electrons in thin metal foils. The momentum transferred is determined with a pair of deflectors; the energy losses are determined with a scanning lens and a hemispherical analyzer having synchronized scanning potentials. The spectrometer characteristics are as follows: energy of the primary beam up to 30 kev, energy resolution approximately 0. 5 ev, momentum resolution approximately 0. 25 A** minus **1, range of energy losses which can be observed 0-200 ev, and range of transferred momentum which can be measured 0-3 A** minus **1.