SPECTROSCOPIC DIAGNOSTICS ON JET
The present spectroscopic diagnostics on JET consist of bolometry, fibre and close coupled visible spectroscopy (200-700 nm), as well as survey (10-170 nm) and spatial scan VUV spectroscopy (10-250 nm). Visible bremsstrahlung is used routinely for Z-eff measurements. Hydrogen and impurity influxes from walls, limiters and RF antennae are derived from visible spectral lines. Visible charge-exchange spectroscopy, utilising part of the JET heating beams, yields ion temperatures, rotation velocities and impurity concentrations in the plasma. VUV spectroscopy is employed for measuring the impurity content in the bulk plasma using an impurity transport code. Spatial scan spectrometers allow verification of the transport models by means of recorded emission shells. A 20 m high resolution crystal spectrometer yields ion temperatures and rotation velocities from the He- and H-like resonance lines, as well as other plasma parameters. A pulse height analysis system covers the energy range of metal and Cl K-lines and can be used for electron temperature measurements. In the near future XUV (0.7-35 nm) and double crystal spectrometers (0.1-2 nm), one of them providing a spatial scan, will be available, enabling studies of H- and He- like light impurities, as well as Ne-, He- and H-like metals. Bolometry, visible spectroscopy and two crystal instruments will be the only diagnostics left during the JET active phase. By then, models and methods must have been established for assessing the behaviour of the important impurities C, O (, Be) and Ni with these diagnostics.
Bibliographic Reference: WRITE TO THE PUBLICATIONS OFFICER, JET JOINT UNDERTAKING, ABINGDON, OXON, OX14 3EA (UK), MENTIONING REPORT JET-P(86)10, 1986
Record Number: 1989125022400 / Last updated on: 1987-02-01
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