DIAGNOSTICS FOR LOCAL SPECTROSCOPIC MEASUREMENTS IN THE DIVERTOR REGION OF THE ALCATOR C-MOD AND DIII-D TOKAMAKS

Local measurements of line emission of either intrinsic or gas puffed impurities will be performed around and below the X point. Such spectr oscopic measurements, together with divertor Thomson scattering and bo lometric imaging will enable estimates of divertor impurity particle d istributions and power losses. A proposed multilayer mirror (MLM) diag nostic mounted inside the tokamak vessel will measure XUV (100-200 Ang strom) emission from impurities at multiple locations in the divertor region of the C-Mod tokamak. A prototype of this instrument measuring N V at 162.6 Angstrom is scheduled to be installed on C-Mod with a sin gle chordal view of the X point. A multichordal/multispectral device u sing MLMs and gratings has been designed for the DIII-D tokamak. The i nstrument will measure the resonance emission of C II to C VI from 40- 2000 Angstrom, thus enabling a more direct and reliable estimate of th e impurity content in the divertor. At DIII-D, the device will be moun ted on a port below the mid plane avoiding spectroscopic contamination from the core plasma. (C) 1997 American Institute of Physics.