Ion source device

Abstract

Abstract PURPOSE:To obtain only negative ion beams of high brightness by periodically providing a negative ion generation part with an electrode for beam deflection and an energy recovery electrode, a negative ion acceleration part with an electrode hole having a radially slipped-off axis and further downstream a set of a negative ion separation electrode and an electrode hole having a radially slipped-off axis. CONSTITUTION:Negative ions and electrons are drawn out 10 as a beam while being accelerated with about 10keV for deflecting the electron beam in a magnetic field less than several gausses of a magnet 11. The electron beam 12 is decelerated in the electric field of an electrode 13 while hitting the electrode 13 with low energy and removed as heat. Electrodes 14 are placed up-and-downstream the electrode 13 for restructing emission of the secondary electrons and the rear-scattered electrons. The negative ion beam is slightly deflected for reaching 15 the acceleration part but for being corrected by radially slipping-off 16 an acceleration electrode hole. Impurity ions are removed by providing a set of a magnet 17 and an electrode 18 having an electrode hole with a radially slipped-off axis periodically in plural steps. With this constitution, a negative ion beam 22 of high brightness not containing electron beams and impurity ions can be obtained.

Inventors

• 👤 Yoshihiro Obara
• 👤 小原　祥裕

Bibliographic Details