End-hall ion source with enhanced radiation cooling

摘要

In accordance with one embodiment of the present invention, an end-Hall ion source has an electron emitting cathode, an anode, a reflector, an internal pole piece, an external pole piece, a magnetically permeable path, and a magnetic-field generating means located in the permeable path between the two pole pieces. The anode and reflector are enclosed without contact by a thermally conductive cup that has internal passages through which a cooling fluid can flow. The closed end of the cup is located between the reflector and the internal pole piece and the opposite end of the cup is in direct contact with the external pole piece, and wherein the cup is made of a material having a low microhardness, such as copper or aluminum.

主权项

1. An end-Hall ion-source apparatus comprising:
(a) an ion generating means comprising;
(i) a discharge region having a first end, a second end, and a side, wherein said first end is open;(ii) an electron emitting means located outside of said discharge region;(iii) an anode which encloses said discharge region at said side;(iv) a reflector, which encloses said discharge region at said second end;(v) means for introducing an ionizable working gas into said discharge region; (b) magnetic-circuit means comprising;
(i) a magnetically permeable internal pole piece located outside of said second end of said discharge region and near said reflector;(ii) an magnetically permeable and thermally conductive external pole piece located around said first end of said discharge region and between said anode and said electron emitting means;(iii) a magnetically permeable path between said internal pole piece and said external pole piece;(iv) a magnetic-field generating means located in said magnetically permeable path; (c) a cooling means comprising a thermally conductive cup having a closed end, a side wall, an open end, and internal passages through which fluid can flow; wherein said cup encloses said anode and said reflector; wherein said closed end is located between said reflector and said internal pole piece; wherein said cup and said external pole piece are in physical contact with each other; and wherein at least one of said cup and said external pole piece is comprised of a material with a low microhardness; and (d) assembly means holding said cup against said external pole piece.