Study of two types of T-10 device regimes with ECR and ohmic heating

The study of two types of T-10 regimes - with low impurity confinement (S-regime) and with enhanced one (B-regime) has been continued in deuterium discharges. In present experiments the transitions from S to B regimes were obtained by method of gas puff cutoff. Detail investigations of profile evolutions of Te(r), Ti(r), ne(r) and carbon density nC showed, that ne profile greatly charges after gas puff cutoff, while Te(r) and Ti(r) remain practically unchanged at the central zone of plasma. It pointed out to the possibility of a relation between ne(r) and either Te(r) or Ti(r). It is shown, that the main cause which is responsible for this transition between B and S regimes, is variations of neutral atom influx to the plasma. The transition itself takes place at a given radius of plasma, when nc reaches some limiting value at this radius