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The concept of multiplexing thermography is applied to the design of the divertor thermography system for International Thermonuclear Experimental Reactor (ITER). The combination of the front mirror with multiellipticity and a Czerney–Turner spectrometer with a 0.2 mm pitched multichannel detector enables a spatial resolution of 3 mm and a time resolution of 20 μs above a target temperature of 300 °C to be achieved. This should be sufficient to measure ELM heat fluxes to the targets in ITER. To satisfy the measurement requirement, it is very important to keep an accurate alignment around the optical axis against movement of the vessel during the plasma discharges. Several key engineering problems, such as the survivability of components against mirror coating by redeposited divertor material, remain to be solved. Potential solutions have been identified. [ABSTRACT FROM AUTHOR]

Recent development of the JT-60U charge exchange recombination spectroscopy (CXRS) diagnostic system is reported. The measurements of the radial profiles of the ion temperatures, the toroidal and poloidal rotation velocities, and the impurity density are based on CXR spectra of fully stripped carbon ions induced by neutral beam injection. Measurements are made simultaneously at 59 spatial points (23 toroidal and 36 poloidal) with a time resolution of 1/60 s throughout the full discharge pulse of 15 s. Considerable effort has been expended to ensure the automatic provision of reliable profile data, where the mechanical components of the system must cope with both a baked tokamak vessel (∼300 °C) and an expected disruption-induced acceleration of up to 60 g, where g denotes the gravitational acceleration, i.e., 9.8 m2/s. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Describes the design of the divertor impurity monitoring system of the International Thermonuclear Experimental Reactor. Main functions of the system; Wavelength range; Three different types of spectrometer; Optimization of the optics by a ray trace analysis.

Examines the feasibility of installing a vacuum ultraviolet spectrometer at the divertor level on the International Thermonuclear Experimental Reactor including the related engineering aspects. Design features and implementation constraints; Vacuum ultraviolet spectra in the divertor leg; Use of the narrow gap between divertor cassettes as access for lines of sight.