Experimental Determination of Hydrogen Isotope Transport Parameters in Vanadium.

Deuterium permeation through vanadium membranes in a wide range of pressures and the temperature range ~250-550 °C was experimentally investigated. Measurements on the same material were carried out in three laboratories with different features for an extended characterization and for cross-check validation. A unified equation for deuterium permeability in pure vanadium (99%) was provided as Φ=1.27×10-4·e-8667/T mol m-1 s-1 Pa-0.5, which represents a significant progress for the characterization of the transport properties in this material, given the spread of data, which can currently be found in the literature. Adsorption and recombination rate constants were also measured for hydrogen and deuterium at low pressure for the same range of temperatures. Finally, the influence of the surface roughness was examined by measuring samples with different surface finish.

A dedicated system for in situ testing of gamma ray induced optical absorption and emission in optical materials.

Serious radiation damage due to the high energy neutron/gamma fluxes is expected for optical materials such as scintillators, windows, and lenses which will be part of the plasma diagnostics in future fusion devices. Radiation induced absorption represents a major concern for these components for which experimental validation under as near as possible reactor conditions becomes essential. A new experimental system has been developed at the CIEMAT Nayade 60Co gamma irradiation facility for in situ radiation induced optical absorption measurements, covering a spectral range between 370 and 730 nm. This setup consists in a rotating sample holder which allows one to collect incident light (reference signal) and transmitted light through the material to be tested as a function of irradiation dose. This is an advanced and robust system which overcomes the important experimental difficulties that radiation involves providing a valuable testing capability for transmission components and scintillators under realistic fusion conditions. A detailed description of the experimental arrangement, together with preliminary tests carried out for system validation is given in this paper.