Statistical Analysis of Particle Flux Flowing into the End-Target in between Attached and Detached States in the Linear Divertor Plasma Simulator NAGDIS-II

We have investigated the particle flux flowing into the axisymmetric end-target in the transient state from attached to detached divertor conditions in the linear plasma device NAGDIS-II. In the transient state, a dramatic decrease of the mean particle flux and a large-amplitude fluctuation with negative and positive spikes were observed. We have analyzed the fluctuation with a newly suggested analysis technique: pre-multiplied cubic spectrum with the wavelet transform. Analysis result indicates that these spikes consist of a few kilohertz components. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)