Characteristics of tungsten and carbon dusts in JT-60U and evaluation of hydrogen isotope retention

Abstract Dust was collected after the installation of tungsten (W)-coated tiles in the outer divertor of the P-8 section in JT-60U (2010). Dusts containing tungsten were analyzed by energy-dispersive X-ray spectrometry (EDX) and X-ray photoelectron spectroscopy (XPS). The tungsten intensities measured by EDX and XPS were obtained dusts from the under-dome regions. From a comparison of a numerical analysis of the tungsten deposition layer and analytical results for the atomic concentrations of tungsten, it was determined that dust containing tungsten was produced on the outer dome wing. Hydrogen isotope retention in the dust particles was analyzed by thermal desorption spectrometry (TDS). Using this analytical method, a wide range of dust particle sizes can be retained. The hydrogen isotope retention on dust particles in JT-60U (measured using a few milligrams of dust particles) is shown, and it was approximately 1.5 × 10 21 (H 2 + HD + D 2 )/g.