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Presents a study that discussed a method to deduce central ion temperature and toroidal rotation velocity from line-of-sight averaged x-ray spectra from hot plasmas. Features of a high-resolution x-ray crystal spectrometer; Analysis of the ion temperature profile; Comparison of the method with other diagnostic technique.

It is shown that a significant increase in the consistency of charge exchange spectroscopy and xray spectroscopy data for central ion temperature and plasma rotation is obtained when allowance is made for the following: (i) The charge exchange cross-section dependence on the impact energy of the neutral beam atoms in the frame-of-reference of the C[sup +6] a nuclei. In this paper we have experimentally verified the predicted cross-section effects on plasma rotation measurements using charge exchange spectroscopy by comparing to passive x-ray spectroscopy. The effect increases with lighter species, It should be emphasized that this effect is important for the rotation measurements only, while for the ion temperature measurements the effect is small compared to other error sources. (ii) The precise position of the radiating ion shell in line-of-sight averaged measurements using x-ray spectroscopy. For high-temperature plasmas with broad emission profiles the uncertainty in central ion temperature is reduced from up to 60% to the order of 20%. [ABSTRACT FROM AUTHOR]

A double-crystal monochromator has been brought into operation at JET to measure absolute wavelengths and intensities of impurity spectral lines in the soft x-ray region from about 0.1 to 2.3 nm. It is capable of operating also during the deuterium-tritium (active) phase of JET because its detector is very effectively shielded against neutrons and hard x rays. The spectrometer has been swept over a wide wavelength range, around characteristic line groups as well as monochromatic line scans. [ABSTRACT FROM AUTHOR]

Application of a double-crystal Bragg device with the one crystal swiveling additionally around the x-ray optical axis between the two crystals allows continuous spatial scanning of x-ray line emission from high-temperature plasmas. The main components and physical properties of the monochromator are described, and first results of measurements of spatial profiles of the emission shells of several nickel ionization stages at JET are given. [ABSTRACT FROM AUTHOR]