Synergy of multiviewing spectroscopic diagnostics on COMPASS-D (invited)

In the COMPASS-D tokamak three multiviewing diagnostic systems are combined by using the same collection optics. HeI line ratios from a helium thermal jet provide detailed edge T-e(r) and n(e)(r) profiles. The spectrometer also provides the D-alpha profile. A Doppler spectrometer system provides T-i and V-theta profiles using HeII emission. The T-e and n(e) profiles are used in extracting neutral densities from the D-alpha emissivities, and the radial electric field from the Doppler measurements. The behavior of T-e(r), n(e)(r), 2n(D)(r), E-r, and V-theta and their gradients can now be compared in detail to investigate the H-mode transition physics. (C) 2001 American Institute of Physics.