Enhancement of JET’s Mirror-Link Near-UV to Near-IR Divertor Spectroscopy System
Since 1994 JET has had a mirror-link spectroscopy system with a poloidal view of 150mm of the outer divertor split into 3 ranges: near-UV (~300-450nm), visible (450-750nm) and near-IR (750-1200nm). The system consists of 3 Czerny-Turner/CCD pairs: 1-meter focal length for the near-UV, imaging 0.75m for the visible, and imaging 0.5m for the near-IR. All were aligned along the same optical path to the divertor. As part of the JET ITER-like wall enhancements, the diagnostic system will be upgraded in 5 areas: 1) Frame-rate, 2) QE, 3) Radial coverage, 4) Optical throughput, and 5) for the near-UV, Spectral resolution and survey capability. New CCD's for the near-UV and visible will have increased QE and allow 3X's frame rate. The near-UV will benefit from a 0.75m imaging spectrometer with 3 gratings. The optics have been redesigned to allow ~360mm view and >2X throughput. The paper will look at the design and implementation as well as the new diagnostic capabilities of the system.