PURPOSE: To achieve a small neutralization unit of large current, in which electron current that can be extracted is not limited by the amount of ions flown in the inner wall of a discharge chamber of the neutralization unit.
CONSTITUTION: A coaxial line 31 for supplying microwave power and a gas guide 24 are connected to one end of a neutralization unit discharge chamber 28, and a small hole 34 is opened on the other end. An annular permanent magnet 29 is arranged on the outer periphery of the neutralization unit discharge chamber 28, and when a negative electric potential to ground is given to a neutralization unit 23 by a power source 41, an electron 41 is extracted from a plasma 40 in the neutralization unit discharge chamber 28, and an ion beam 37 is neutralized. Ions 42 of the same amount of the extracted electrons 41 are flown into the inner wall of the neutralization unit discharge chamber 28.
ONO YASUNORI
NATSUI KENICHI
OISHI SEITARO
ONUKI HISAO
