Electron source with magnetic means

摘要

The instant invention relates to an electron source which contains, in a low pressure chamber, an anode (A), a cathode (K) and means for applying a magnetic field (13). The cathode is constituted by an equipotential cavity (10) provided with an aperture (11) on the side of the anode. The magnetic field is applied parallel to the anode-cathode direction at the aperture.