Estimations of the plasma effective charge at the L-2M stellarator after boronization of its vacuum chamber on the basis of measurements of a soft X-ray spectrum and plasma conductivity
Boronization of the vacuum chamber walls resulted in a considerable change in the impurity composition of plasma generated in the working pulses at the L-2M stellarator and, consequently, in the plasma effective charge. We present the results of measurements of the plasma effective charge carried out in the OH operation mode by two methods: from measuring plasma conductivity and from the SXR spectrum of plasma emission. We compared the values of plasma effective charge obtained by these two methods and qualified the conditions in which the two values are in good agreement. Under these conditions, the effective charge of plasma can be correctly estimated from spectral measurements