[en] The depth distribution of C, N, and O was measured in the damage layer of a series of heavy-ion irradiated samples of V and V alloyed with C, O, N, Cr, or Ti. Ion-beam analysis using the simultaneously induced nuclear reactions ¹²C(d,p/sub o/)¹³C, ¹⁶O(d,p/sub l)¹⁷O, and ¹⁴N(d,α/sub l/)¹²C provided the C, N, and O distributions to a depth of 2 μm. The profiles were studied as a function of irradiation temperature and displacement dose produced by MeV V or Ar ions. Displacement dose rates of approx.3 x 10^-3 dpa/s provided peak-damage doses of up to approx.30 dpa, at irradiation temperatures between 250 and 880⁰C. The dominant effect observed was a large enrichment of C, up to approx.20 times the bulk C concentration, in the damage zone of most of the irradiated samples. The C enrichment occurred between approx.400 and approx.700⁰C, and increased with irradiation dose. A similar enrichment of C occurred on the sample surface over the same temperature range. The surface C enrichment was associated with V₃C precipitates on the sample surface, while the damage-zone C enrichment was associated with an irradiation-induced coherent ]012] habit-plane precipitate

No abstract available

[en] Helium clustering behaviour in molybdenum, which is of interest in fusion reactor environments, has been investigated using thermal helium desorption spectrometry and transmission electron microscopy. Evidence is presented showing that, at least in molybdenum, helium can initially aggregate in an unexpected planar form. A bubble nucleation route involving the formation of several small bubbles from a single helium platelet has also been found. (U.K.)

[en] SiO₂ films, irradiated with 80 keV Ar⁺ ions and subsequently thermally annealed, were analyzed by electron diffraction

[en] By implanting a dose of 6 x 10¹⁷ cm^-2 of ³²O₂⁺ at 300 keV into a silicon wafer, a buried oxide layer is formed. Crystallinity of the silicon layer above the buried oxide layer is maintained by applying a high (>200⁰C) substrate temperature during the ion implantation process. A two-step anneal cycle is found to be adequate to form the insulating buried oxide layer and to repair the implantation damage in the silicon layer on top of the buried oxide. A surface electron mobility as high as 710 cm²/Vs has been measured in n-channel MOSFETs fabricated in a 0.5 μm-thick epitaxial layer grown on the buried oxide wafer. A minimum subthreshold current of about 10 pA per micron of channel width at Vsub(DS)=2 V has been measured. (author)

No abstract available

[en] Effect of gamma irradiation on low-temperature thermal conductivity of MgO crystals has been investigated. Spectra of optical absorption and EPR were measured sumultaneously. Structural distortions of the lattice in the form of the Frenkel pairs of defects take place in the irradiation process along with change in the valent state of paramagnetic ion (Fe²⁺→Fe³⁺, Cr³⁺→Cr²⁺). It is established that the radiation change of thermal conductivity is determined with the above valent transformations: phonon scattering with Cr²⁺ ions. The thermal conductivity of the MgO crystals has been calculated with provision for the phonon scattering by radiation distortions. Cr²⁺ ion concentration values and data on the efficiency of the Rayleigh and anharmonic phonon scatterings in the MgO crystals have been obtained from the comparison of calculational results and corresponding experiments

No abstract available

[en] Electrical insulating liquids, so as transformer oil, may be influenced by ionizing radiation, e.g. near a nuclear reactor. The irradiation of new mineralic transformer oil with ⁶⁰Co-γ-radiation as a function of the energy dose may give evidences with regard to the changes of physical values, mainly the dielectric properties. (orig.)

[en] Tensile property data on 20% cold worked 316 stainless steel irradiated in fast and thermal reactors and by 14 MeV neutrons were analyzed and equations were developed to describe the yield strength and ultimate tensile strength behavior for the temperature range 25 < T < 800⁰C. The correlation equations include the irradiation parameters: displaced atoms, helium content, and irradiation temperature. The uniform elongation data were characterized in terms of the yield and ultimate tensile strength. The total elongation was found to be insensitive to helium at temperatures below 500-550⁰C but sensitive to helium above these temperatures. (orig.)