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Results of testing of a possible method for location of water microleakages in the cooling system of the first wall and vacuum chamber of ITER are presented. The method consists in spectroscopic detection of the emission lines of atoms and ions of the Xe additive dissolved in water. These lines are excited when the water with dissolved Xe contacts the plasma. The high electron cyclotron resonance heating (ECRH) power deposited in a relatively small plasma volume in the L 2M stellarator (P = 0.5 MW, V = 0.24 m 3 , and the spe cific heating power ~2 MW/m 3 ) makes it possible to achieve plasma parameters close to those in the edge plasma of ITER for different operating modes, including the H mode with an edge transport barrier. In test experiments, several lines of Xe ions were revealed suitable for detection of xenon in plasma with parameters close to those in the edge plasma of ITER at leakage rates at a level of ~10 -6 Pa m 3 s -1 and spatial resolution of ~0.5 cm.

Head-on domains having saw-tooth wall configurations in Ni/Fe/Co films are discussed in relation to the existing theoretical models. The existence of Ndel tails within such wall structures as previously proposed is supported and discussed with respect to: (a) direct magneto-optic observations and measurements, and (b) a comparison of the predicted saw-tooth amplitude and angles with the observed values.A large number of films were investigated and the wall angles were found to be dependent upon the ratio of the coercivity to anisotropy field, Hc/ffk, as predicted in the Ndel tail model, whilst the saw-tooth amplitude was determined predominantly by the coercivity. Effective wall widths of the order of 100 Km have been observed in 0.14 pm thick 18/17/3 Ni/Fe/Co films.

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