AC and Mechanical Loss Analysis of the ITER PF RF SULTAN Samples

Analysis of the ac and mechanical losses of PF RF ITER SULTAN sample test results has been performed. Measurements were provided by the gas flow colorimetric method before and after cyclic mechanical loads. The mechanical loss investigation was carried out for the virgin sample and after 10, 400, and 1000 cycles. Mechanical loss, as it was expected, significantly decreased after the first ten cycles but remained almost the same after the subsequent cycling. The value of mechanical loss even of the virgin sample does not strongly affect the workability of a magnet. AC loss measurements were carried out at different operating currents in conductor, at background magnetic field of 2 and 4.5 T before and after cycling. The ac loss measurements of all tested samples were practically the same before and after cycling, but strongly depended on a background magnetic field. As an example, at zero operating current in conductor and variable magnet field frequency of 6 Hz, the ac loss decreased by ~1.4 times at background magnetic field of 4.5 T compared with the loss at 2.0 T. An attempt to explain the phenomena has been done. The results of the calculation and experimental investigation are presented.