Communications Internationales

Permanent URI for this collectionhttps://dspace.univ-boumerdes.dz/handle/123456789/11

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Start date: 1998End date: 1999

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    Speed-up of high accuracy analog test stimulus optimization
    (1999) Khouas, Abdelhakim; Derieux, Anne
    Analog integrated circuit testing and diagnosis is a very challenging problem. The inaccuracy of measurements, the infinite domain of possible values and the parameter deviations are among the major difficulties. During the process of optimizing production tests, Monte Carlo simulation is often needed due to parameter variations, but because of its...
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    Influence of surface roughness on the deuterium inventoryof ASDEX-UPGRADE divertor tiles
    (1998) Hildebrandt, D.; Akbi, Mohamed; Jüttner, B.; Schneider, W.
    The gas inventory of divertor target tiles used in ASDEX-UPGRADE has been analyzed by thermodesorption spectrometry (TDS°. desorbed gaseous molecules have been measured by heating up complete and cut divertor tiles. the largest samplrs '80X80mm2)could be heated up to temperatures of 1500 K and smaller ones to even higher temperatures.in addition, surface analysis techniques as auger electron spectroscopy (AES),secondary ion mass spectrometry(SIMS), nuclear reaction analysis (NRA), electron microscopy and optical surface profiling have been applied for investigating erosion and deposition phenomena. the original plasma facing surface of the tiles were graphite (EK98) and plasma sprayed tungsten, respectively. the graphite tiles were used from 1991-1995 for about 1900 discharges and the tungsten tiles in 1996 for about 800 discharges...
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    Deuterium and impurity contamination of divertor tiles and collector probes of asdex-upgrade
    (Fusion and plasma physics, 1998) Hildebrandt, D.; Akbi, Mohamed; Jüttner, B.; Rohde, V.; Schneider, W.
    The uptake and release of hydrogen isotopes at the plasma-facing components in magnetic, confinement fusion devices affects the working gas recycling, the plasma behaviour and the tritium inventory [1]. This attracts considerable interest in the investigation of hydrogen trapping during plasma exposure. The most intensive plasma material interaction occurs on limiters and divertor plates. Post-mortem analysis of such components gives information on the total amount of hydrogen isotopes retained in the material after plasma exposure. Recent investigations of divertor tiles of ASDEX-UPGRADE have shown that the dominant trapped deuterium amount is contained in the deposited material at the surface [2]. This surface contamination consists mainly of carbon, boron and the hydrogenic isotopes. Movable collector probes have been applied to investigate the hydrogen trapping and impurity deposition under specific plasma conditions. In the present paper results on the impurity and deuterium contamination at the surface of collector samples are presented and compared with corresponding results from the divertor tiles. The collector samples were exposed to the scrape-off plasma of the main chamber (SOL-probe) and to the divertor plasma (DIV-probe)