Compact Plasma and Focused Ion Beams

181

11

Power Absorption and Intense Collimated

Beam Production in a Pulsed High-Power

Microwave Ion Source

Introduction

ECR ion sources have been the subject of active research for many years

[1,2]. These ion sources normally operate at lower pressures (10

−5

–10

−8

Torr)

and moderate values of microwave power (~1 kW), primarily because of the

reduction in the efciency of ECR action at higher pressures (>10

−4

Torr) and

stringent cooling requirements. While operation at a lower pressure is favor-

able for obtaining higher charge states, the beam intensity is considerably

limited (approximately electron microamperes) due to a lack of sufcient

number ...