Plasma spectroscopy of metal ions for hyper-electron cyclotron resonance ion sourcea

In this research, the optical line spectra of metal ions from ECR plasma were observed using a grating monochromator with a photomultiplier. The light intensity of line spectrum from the ECR plasma had a strong correlation with ion beam intensity measured by a magnetic mass analyzer. This correlation is a significant information for the beam tuning process, because it allows to conduct the extraction of the desired metal ion species from the ECR plasma. Separation of ion species of the same charge to mass ratio with an electromagnetic mass analyzer is known to be an exceptionally complex process, but this research provides a new approach for its simplification. In this paper the grating monochromator method for metal ion beam tuning such as 40Ca12+, 56Fe15+, and 85Rb20+ of hyper-ECR ion source as an injector for RIKEN Azimuthal Varying Field cyclotron is described.