Two soft X-ray pulse height analysis (PHA) systems, based on silicon drift detec-tor (SDD), were established on the experimental advanced superconducting tokamak (EAST) tomeasure spectrum of soft X-ray emission. In this paper, the soft X-ray PHA systems on EASTare introduced and some experimental results of electron temperature in EAST obtained from thesoft X-ray PHA diagnostic are presented.
The plasma facing component in HL-2A has been damaged seriously after disruption,and for this reason its operation is suspended for maintenance.The experimental phenomena and plasma configurations,calculated by the current filament code(CF-code) using the plasma parameters measured by diagnostics and the signals of the magnetic probes,confirm that the first wall is damaged by the synergetic effects of runaway electrons and disruption induced by a vertical displacement event(VDE).When the plasma column is displaced upward/downward,the strong runaway electrons normally hit the baffle plate of the MP 3 or MP 1 coil in the upper and lower divertor during the disruption,causing the baffle plates to be holed and wrinkled by the energetic runaway current,and water(for cooling or heating the baffle plates) to leak into the vacuum vessel.Another disastrous consequence is that bellows underlying the baffle plate and outside the coil of MP 3 for connecting two segments of the jacket casing pipe are punctured by arcing.The arc may be part of the halo current that forms a complete circuit.The experimental phenomena are indirect but compelling evidence for the existence of a halo current during the disruption and VDE,though the halo current has not been measured by the diagnostics in the HL-2A tokamak.
