Abstract. The results of impurity penetration studies at T-11M tokamak just before and during the disruption are presented. Two scenarios of the process are considered: (i) initiated by the major disruption, the latter being the main source of impurity, and (ii) minor disruption or Locked Mode (LM) provide preliminary impurity penetration into the periphery followed by deep internal disruption. Well-known ``vacuum bubble'' capture model is proposed for the explanation of rapid impurity penetration.
IAEA 2001