Spatial profile measurements of ion-confining potentials using novel position-sensitive ion-energy spectrometer arrays

The first experimental demonstration of simultaneous measurements of temporally and spatially resolved ion-confining potentials <f>φc</f> and end-loss-ion fluxes <f>IELA</f> has been carried out during a single plasma discharge alone by the use of newly designed ion-energy-spectrometer arrays installed in both end regions of the GAMMA 10 tandem mirror. This position-sensitive ion-detector structure is proposed to obtain precise ion-energy spectra without any perturbations from simultaneously incident energetic electrons into the arrays. The relation between <f>φc</f> and <f>IELA</f> is physically interpreted in terms of Pastukhov’s potential confinement theory. In particular, the importance of axisymmetric <f>φc</f> formation is found for the plasma confinement. [Copyright &y& Elsevier]