X-ray emission from tokamaks

The attainment of ion temperatures in the 20 keV region in supershots on the TFTR tokamak deduced from X-ray and vacuum ultraviolet Doppler broadening measurements has demonstrated the importance of spectroscopic techniques for controlled thermonuclear fusion research. A survey of the present status of investigation of the spectral emission in the X-ray region is presented. Special emphasis is placed on new results and unresolved problems. The survey covers the important n = 2 to 1 transitions, i.e., hydrogen-like and helium-like spectra, and also n = 3 to 2 transitions, especially neon-like spectra, which have been studied intensively in recent years. In addition, the important diagnostic applications of X-ray spectroscopy like ion temperature measurements or impurity transport studies are also discussed. Of these applications, the measurement of plasma rotation velocities has become very important, because supershots require balanced injection.