Spectroscopic measurement in the tandem mirror gamma 10 for plasma confinement and impurity diagnostics

We have constructed a 2-dimcnsional Ha line-emission measurement system in order to stud)1 neutral hydrogen behavior. We can obtain 2-dimensional radial profiles of hydrogen density by considering a collisional-radiative model. We have also constructed space- and time-resolving spectrograph system in the range of vacuum ultraviolet (VUV). 15 - 105 nm. studying ion density profiles which directly relates to impurity transport. We measure both Hα line-emissions and VUV spectra from the hot ion mode plasmas in the GAMMA 10 for studying plasma panicle confinement and impurity behavior. We found that both particle and energy confinement of the GAMMA 10 plasma was slightly improved during electron cyclotron resonant heating (ECRH) over that without ECRH. From the VUV measurement it is concluded that the impurity ions mainly came into the plasma during its formation phase.