Design of Lost Fast-Ion Probe Based on Thin Faraday Films in Heliotron J

A lost fast-ion probe based on thin Faraday films (FLIP) is designed to measure fast-ion losses caused by fast-ion-driven MHD modes as well as magnetic field ripples in Heliotron J. The FLIP works as a magnetic spectrometer providing the energy and pitch angle of lost fast-ions. The installation location of FLIP is studied using Lorentz orbit code. Upper port of Heliotron J at the corner section is a primary target to install the FLIP, because not only co-going fast ions but also counter-going fast ions will be detected at this position. The FLIP will give the decisive information to study fast-ion losses in Heliotron J.