H Measurements in the Plug/Barrier Cells of the Tandem Mirror GAMMA 10

In the GAMMA 10 tandem mirror, neutral hydrogen densities in the central-cell and anchor-cell have been estimated by measuring spatial profiles of H line-emission with absolutely calibrated H line-emission detectors. Absolute measurements of H line-emission enable us to evaluate the neutral density based on the collisional-radiative model. Recently, single channel H line-emission detectors were installed in plug/barrier cells, where the axial confining potentials are produced by electron cyclotron resonance heating. We studied the neutral particle behavior in the plug/barrier cells for the first time using the newly installed H line-emission detectors. Moreover we have designed and installed a multi-channel H line-emission detector system to study the neutral hydrogen behavior in the plug/barrier cell.