Development of new measurement techniques for application of glow discharge optical emission spectroscopy to plasma-surface interaction studies

Glow-discharge optical emission spectroscopy (GDOES) allows high resolution and rapid depth profiling of constituent elements in a solid specimen. These features are in principle suitable for the analysis of plasma-facing materials (PFMs) used in fusion devices. There are, however, special requirements for PFM analysis: (1) isotope analysis, (2) quantitative measurement of hydrogen isotopes, (3) helium detection, and (4) influence of hydrogen isotope content on sputtering rate of materials. This study has revealed that (1) resolution of diffraction grating in a commercial GDOES device is sufficiently high to separately detect H and D, (2) thin films of hydrogen absorbing materials are suitable as a standard sample for quantitative analysis of hydrogen isotopes, (3) helium detection is possible using high power, high pressure Ne plasma and (4) there is no significant influence of hydrogen isotope content on sputtering rate of carbon-hydrogen co-deposited films.