Absolute calibration of a SPRED EUV spectrograph for use on the DIII-D tokamak (abstract)

We have performed an absolute intensity calibration of a SPRED multichannel EUV spectrograph1 using synchrotron radiation from the NBS SURF-II electron storage ring. The calibration procedure and results for both a survey (450 g/mm) and a high-resolution (2100 g/mm) grating are presented. The spectrograph is currently in use on the DIII-D tokamak with a tangential line-of-sight at the plasma midplane. Data are first acquired and processed by a microcomputer; the absolute line intensities are then sent to the DIII-D database for comparison with data from other diagnostics. Representative absolute line brightnesses for ohmic, L-mode, and H-mode plasma operations will be presented. This work was supported by the U.S. DOE Contracts W-7405-ENG-48 and DE-AC03-84ER51044.