477 research outputs found

    Paramagnetic gold in a highly disordered Au-Ni-O alloy

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    Magnetic materials are usually classified into a distinct category such as diamagnets, paramagnets or ferromagnets. The enormous progress in materials science allows one nowadays, however, to change the magnetic nature of an element in a material. Gold, in bulk form, is traditionally a diamagnet. But in a ferromagnetic environment, it can adopt an induced ferromagnetic moment. Moreover, the growth of gold under certain conditions may lead to a spontaneous ferromagnetic or paramagnetic response. Here, we report on paramagnetic gold in a highly disordered Au–Ni–O alloy and focus on the unusual magnetic response. Such materials are mainly considered for plasmonic applications. Thin films containing Au, Ni and NiO are fabricated by co-deposition of Ni and Au in a medium vacuum of 2 × 10−2 mbar. As a result, Au is in a fully disordered state forming in some cases isolated nanocrystallites of up to 4 nm in diameter as revealed by high resolution transmission electron microscopy. The disorder and the environment, which is rich in oxygen, lead to remarkable magnetic properties of Au: an induced ferromagnetic and a paramagnetic state. This can be proven by measuring the x-ray magnetic circular dichroism. Our experiments show a way to establish and monitor Au paramagnetism in alloys

    Scintillators and Cherenkov detectors for the registration of 10.8 MeV gamma rays

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    © Published under licence by IOP Publishing Ltd. The identification of nitrogen by neutron activation has been utilized in both explosive detection and in-vivo metabolic analysis. The 10.8 MeV gamma ray line emitted by thermal neutron capture provides a unique signature, however, due to its high energy its registration is non-trivial. Conventional approaches have used large dense inorganic scintillators which inevitably entail considerable expense. We examine the capabilities of arrays of smaller scintillation detectors and the use of glass Cherenkov detectors as an alternative

    D6.3 Intermediate system evaluation results

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    The overall purpose of METIS is to develop a 5G system concept that fulfil s the requirements of the beyond-2020 connected information society and to extend today’s wireless communication systems for new usage cases. First, in this deliverable an updated view on the overall METIS 5G system concept is presented. Thereafter, simulation results for the most promising technology components supporting the METIS 5G system concept are reported. Finally, s imulation results are presented for one relevant aspect of each Horizontal Topic: Direct Device - to - Device Communication, Massive Machine Communication, Moving Networks, Ultra - Dense Networks, and Ultra - Reliable Communication.Popovski, P.; Mange, G.; Fertl, P.; Gozálvez - Serrano, D.; Droste, H.; Bayer, N.; Roos, A.... (2014). D6.3 Intermediate system evaluation results. http://hdl.handle.net/10251/7676

    Modelling of the effect of ELMs on fuel retention at the bulk W divertor of JET

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    Effect of ELMs on fuel retention at the bulk W target of JET ITER-Like Wall was studied with multi-scale calculations. Plasma input parameters were taken from ELMy H-mode plasma experiment. The energetic intra-ELM fuel particles get implanted and create near-surface defects up to depths of few tens of nm, which act as the main fuel trapping sites during ELMs. Clustering of implantation-induced vacancies were found to take place. The incoming flux of inter-ELM plasma particles increases the different filling levels of trapped fuel in defects. The temperature increase of the W target during the pulse increases the fuel detrapping rate. The inter-ELM fuel particle flux refills the partially emptied trapping sites and fills new sites. This leads to a competing effect on the retention and release rates of the implanted particles. At high temperatures the main retention appeared in larger vacancy clusters due to increased clustering rate

    Overview of the JET ITER-like wall divertor

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