We developed a spectrometer specialized for simultaneous observation of the hydrogen Balmer-␣, -␤, -␥ lines and the Fulcher-␣ vЈ = vЉ = 2 rovibronic transition band. The spectrometer was optimized for the light input coupled by nine optical fibers having 400 m core diameters. The spectral resolutions were 0.02-0.03 nm for these wavelength ranges at the entrance slit width of 20 m. The polarization resolved spectra of these emissions from the peripheral region of large helical device ͑LHD͒ plasmas were measured simultaneously and showed the polarization dependence coming from the magnetic field in the LHD plasma.

A scheme for computation of emission spectra of light diatomic molecules under external magnetic and electric fields is presented. As model species in fusion edge plasmas, the scheme is applied to polarization-resolved emission spectra of H 2 , CH, C 2 , BH and BeH molecules. The possibility of performing spatially resolved measurements of these spectra is examined.

We have developed a spectrometer specialized for simultaneous observation of helium emission lines from n = 3 to n = 2 levels, where n is the principal quantum number. The spectrometer is optimized for the light input coupled by 10 optical fibers having 0.4 mm core diameter. The spectral resolutions are 0.016-0.026 nm for the 2 3 P-3 3 D (587.6 nm), 2 1 P-3 1 D (667.8 nm) and 2 3 P-3 3 S (706.5 nm) transition lines for an entrance slit width of 35 µm. The polarization resolved spectra of a Large Helical Device (LHD) plasma are measured with the spectrometer. From the analysis of the spectra with a leastsquare fit assuming the emission locations to be localized in two positions, inner and outer periphery regions, we deduce the emission locations and intensities of these lines. The deduced results are compared with a one-dimensional penetration model of helium atoms based on collisional-radiative calculation. The systematic dependence of the emission locations and intensities on the transition lines reflects the spatial distribution of the electron density and temperature in the periphery region where neutral helium atoms penetrate from the edge.

We have simultaneously measured high resolution emission spectra of the hydrogen atomic Balmer-,-,-lines and molecular Fulcher- band for a LHD peripheral plasma generated under a central magnetic field strength of 0.4 T. It is found that the velocity distributions of excited atoms calculated from the Balmer-,-, and-line shapes show similar profiles to each other. The translational kinetic energy corresponding to the average velocity is about 13 eV, which is about 300 times larger than the rotational energy of hydrogen molecules estimated from the line intensities in the Fulcher- band. The velocity distributions differ from Maxwellian and have a high velocity tail over 1 x 10 5 m/s. A correlation between the high velocity tail and the electron temperature and density is seen and suggesting the excited atoms having such high velocities to be generated by the charge exchange collisions from high velocity protons in the peripheral region.