High Resolution Spectroscopy in the Divertor and Edge Regions of Alcator-C Mod and Measurement of Radiative Transfer in Vacuum-UV Line Emission from Magnetic Fusion Devices

In initial spectroscopic measurements on the Maryland Centrifugal Experiment (MCX), rotation velocities and directions for C, C, C and N ions and neutral hydrogen atoms have been obtained from the Doppler shifts of visible spectral lines. Ion and neutral temperatures have also been determined from Doppler broadening. Different rotation velocities and temperatures are observed for the different species. The direction of rotation is found to be consistent with the predicted E r × B z r z E B  direction; and it reverses with the direction of the magnetic field. The magnitudes of the rotation velocities were of the same order as estimated from the plasma-stored energyapplied voltage and magnetic field. For the C, C and C species, rotation velocities of 20 – 30 km/sec, 40 – 70 km/sec and 60 – 100 km/sec are observed, respectively. The corresponding temperatures are 10 – 12 eV, 20 – 40 eV and 25 – 40 eV. Neutral hydrogen atoms are observed to rotate with velocities ~10 km/sec and with temperatures ~ 5 – 10 eV. These ion velocities and temperatures correspond to sonic Mach numbers (uφ / cs) ranging from 1 – 2. Variations of rotation velocities and temperatures with axial magnetic field, radial electric field, and mirror ratio are described. An electron temperature of ≈ 15 eV is inferred from the relative line intensities from different ionic species of carbon, which is consistent with the lack of observable C emission.