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CCFE-PR(15)382015
Using in-situ transmission electron microscopy, we have directly observed nano-scale defects formed in ultra-high purity tungsten by low-dose high energy self-ion irradiation at 30K. At cryogenic temperature lattice defects have reduced mobility, so these microscope observations over a window on the initial, primary damage caused by individual coll…
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2015
This study examines clustering and hardening in W–2 at.% Re and W–1 at.% Re–1 at.% Os alloys induced by 2 MeV W + ion irradiation at 573 and 773 K. Such clusters are known precursors to the formation of embrittling precipitates, a potentially life-limiting phenomenon in the oper- ation of fusion reactor components. Increases in hardness were …
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2015
Nanoindentation has been performed on tungsten, unimplanted and helium-implanted to $ 600 appm, at temperatures up to 750 1 C. The hardening effect of the damage was 0.90 GPa at 50 1 C, but is negligible above 450 1 C. The hardness value at a given temperature did not change on re-testing after heating to 750 1 C. This suggests that the helium is t…
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CCFE-PR(15)142015
The effects of ion irradiation in materials for research are usually limited to a shallow surface layer of the order of one micrometre in depth. Determining the mechanical properties of such irradiated materials requires techniques with high spatial resolution. Nanoindentation is a relatively simple method for investigating these shallow layers wit…
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2014
The erosion and high neutron flux in a fusion power plant results in the need for frequent remote replacement of the plasma facing components. This is a complex and time consuming remote handling operation and its duration directly affects the availability and therefore the commercial viability of the power plant. A tool is needed to allow the main…
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2014
The need to populate the fusion materials engineering data base has long been recognized, the IFMIF facility being the present proposed neutron source for this purpose. Re-evaluation of the regulatory approach for the EU proposed DEMO device shows that the specification of the neutron source can be reduced with respect to IFMIF, allowing lower risk…
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2014
The materials engineering data base relevant to fusion irradiation is poorly populated and it has long been recognized that a fusion spectrum neutron source will be required, the facility IFMIF being the present proposal. Reevaluation of the regulatory approach for the EU proposed DEMO device shows that the purpose of the source can be changed from…
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2013
Application of lower hybrid (LH) current drive in tokamak plasmas can induce both co- and countercurrent directed changes in toroidal rotation, depending on the core q profile. For discharges with q0 < 1, rotation increments in the countercurrent direction are observed. If the LH-driven current is sufficient to suppress sawteeth and increase q0 abo…
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2013
Pure Fe and model Fe-Cr alloys containing 5, 10 and 14%Cr were irradiated with Fe+ ions at a maximum energy of 2MeV to the same dose of 0.6dpa at temperatures of 300°C, 400°C and 500°C, and at dose rates corresponding to 6 x 10-4 dpa/s and 3 x 10-5 dpa/s. All materials exhibited an increase in hardness after irradiation at 300°C. After irradiat…
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2013
This work presents new integral data measured at the ASP 14 MeV neutron irradiation facility at Aldermaston in the UK, which has recently become available for fusion-related work through the CCFE materials programme. Measurements of reaction products from activation experiments using elemental foils were carried out using gamma spectrometry in a hi…
Showing 21 - 30 of 35 UKAEA Paper Results