Spectrum identification of heliotron E plasma impurities by a time-resolving grazing incidence spectrometer with a multichannel detector

A flat field vacuum ultraviolet spectrometer with a multichannel detector has been constructed to identify impurity spectral lines over the wavelength from 100 Å to 400 Å in Heliotron E plasmas. The resonance emissions of iron, titanium, chromium and nickel ions were identified in heated plasma by ion cyclotron range of frequency (ICRF) pulse. The lines were enhanced as ICRF power increased. The possible sources of these impurities are discussed briefly.