Hydrogen isotope accumulation in the helium implantation zone in tungsten

Effect of Energetic Helium ion Implantation on Hydrogen Isotope Retention in Silicon Carbide

The effects of He retention and damage introduction on the D retention in SiC were studied by changing the implantation energy of He from 0.75 keV to 4.0 keV. The D and He retentions in SiC and chemical behavior of SiC were evaluated by means of thermal desorption spectroscopy (TDS) and X-ray photoelectron spectroscopy (XPS). It was found that the D retention decreased by the He retention in th...

Helium Cooled Tungsten Heat Sinks

Hydrogen and helium isotope inner radiation belts in the Earth's magnetosphere

Radial transport theory for inner radiation zone MeV ions has been extended by combining radial di€usive transport and losses due to Coulomb friction with local generation of D, T and He ions from nuclear reactions taking place on the inner edge of the inner radiation zone. Based on interactions between high energy trapped protons and upper atmospheric constituents we have included a nuclear re...

Damage studies on irradiated tungsten by helium and argon ions in a plasma focus device

Damage of tungsten due to helium and argon ions of a PF device was studied. Tungsten samples were irradiated by 20 shots of the plasma focus device with argon and helium as working gases, separately. The tungsten surface was analyzed by SEM, before and after irradiation. SEM revealed dense blisters with diameters of a few hundred nanometers, on the samples which were irradiated by helium ions, ...

The Dynamics and Helium Distribution in Hydrogen-helium Fluid Planets

In the preceding paper (Paper I) we discussed the thermodynamic and microscopic transport properties of hydrogen-helium fluid mixtures. These results are used in the present paper for a semiquantitative analysis of the thermal and compositional history of an evolving hydrogenhelium planet such as Jupiter or Saturn. First, the evolution of a homogeneous planet with no first-order phase transitio...