Development of an 11-channel multi wavelength imaging diagnostic for divertor plasmas in MAST Upgrade

Divertor detachment and alternative divertor magnetic geometries are predicted to be promising approaches handle the power exhaust of future fusion devices. In order understand process caused by volumetric losses in geometries, a Multi-Wavelength Imaging (MWI) diagnostic has recently been designed built for Mega Amp Spherical Tokamak Upgrade. The MWI will simultaneously capture 11 spectrally filtered images visible light emitted from plasmas provide crucial knowledge interpretation observations modeling efforts. This paper presents optical design, mechanical hardware, test results an 11-channel system with field view 40°. design shows better than 5 mm FWHM spatial resolution at plasma on all channels across whole view. spread angle incidence surface each filter is also analyzed inform bandwidth specification interference filters. initial laboratory tests demonstrate that achieved channels, meeting specifications required accurate tomography.