Negative ion volume production in electron cyclotron resonance hydrogen plasmas

Production and control of electron cyclotron resonance (ECR) plasmas for negative ion sources have been studied. A new production method using permanent magnets is proposed as one possibility for generating a large-diameter high-density uniform microwave plasma. The microwave power is launched by an annular slot antenna into the circumference of a chamber with a ring-cusp or a line-cusp permanent magnet, where a magnetic field can be applied in a local region and plasmas can be efficiently generated if the ECR condition is satisfied. In this paper, we report the structure of the ECR negative ion source: the characteristics of the ECR plasmas, and the comparison of the ECR plasmas with DC discharge plasmas from the viewpoint of a negative ion source.