Development of laser induced fluorescence diagnostic for measuring the parameters of plasma containing rare gas species

Laser induced fluorescence (LIF) technique development activity for measurement of plasma parameters in ITER divertor plasma is described. Helium density is the task of priority, but Doppler measurement of ion (atom) temperatures is also the aim of the program. The concept of ITER scenarios includes injection of ''extrinsic'' impurities (Ne, Ar, and Kr). It is possible to use the species as tracing elements for measurement of Ti, Ta. The program included modeling experiments on PNX-U (a multicusp trap with microwave argon plasma). Helium was added by puffing into discharge. Temperatures Ti(Ar1+) and Ta(He0) have been measured by scanning laser line across absorption line of species. Summarizing of fluorescence signals provided input data for estimation of Ar1+ and He0 densities via interpretative collisional-radiative models. Besides, the collisional-radiative model has been used for estimation of electron density using the ratio of fluorescence signals at 388.9 and 706.5 nm helium lines.