DUAL-PURPOSE DIAGNOSTICS OF EDGE PLASMAS OF TOKAMAKS BASED ON A NOVELSPECTROSCOPIC EFFECT

A significant enhancement of beam-spectroscopy diagnostics is proposed : it is shown that polarization analysis of L(alpha) emission from a n eutral hydrogen or deuterium beam allows to measure both the magnetic field pitch angle gamma(p) and an effective charge Z(eff) simultaneous ly The suggestion is based on a novel, generalized semiclassical theor y of ion impact broadening in high-temperature, magnetized plasmas. A series of generalized theories that the authors had developed recently , represented a significant advancement in accuracy over the standard semiclassical theories. This was achieved by using symmetries of the h ydrogenlike quantum systems in electromagnetic fields and treating one component of the dynamic electric microfield much more precisely that the standard theories did. The novelty of the present generalized the ory is that the ion impact broadening of magnetically splitted levels of beam atoms is highly anisotropic, resulting in a pronounced angular dependence of widths of pi- and sigma-components of spectral lines. ( C) 1997 American Institute of Physics.