An 8.5 cm multipole ion source for an MM-2U neutral beam injector has
been developed. The source is operated with a discharge current of mor
e than 200 A. The saturation ion current at the plasma grid is 300 mA/
cm2. A hydrogen ion current of 9 A has been obtained at an accel. volt
age of 25 kV with 50 ms pulse duration. This article describes the exp
eriment apparatus and the experimental results.