Enhancement of JET's mirror-link near-ultraviolet to near-infrared divertor spectroscopy system

Since 1994, JET has had a mirror-link spectroscopy system with a poloidal view of 150 mm of the outer divertor split into three ranges: near-ultraviolet (near-UV) (similar to 300-450 nm), visible (450-750 nm), and near-infrared (near-IR) (750-1200 nm). The system consists of three Czerny-Turner/charge coupled device (CCD) pairs: 1 m focal length for the near-UV, 0.75 m focal length for the visible, and 0.5 m focal length 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 five areas: (1) frame rate, (2) quantum efficiency (QE), (3) radial coverage, (4) optical throughput, and (5) for the near-UV, spectral resolution and survey capability. New CCDs for the near-UV and visible will have increased QE and allow three times frame rate. The near-UV will benefit from a 0.75 m imaging spectrometer with three gratings. The optics have been redesigned to allow similar to 360 mm view and greater than two times throughput. This paper will look at the design and implementation as well as the new diagnostic capabilities of the system. [doi:10.1063/1.3502322]