29th Symposium on Fusion Technology (SOFT 2016)

P3.015 SST-1 up-gradation update & recent experiments in SST-1

7 Sep 2016, 11:00

1h 20m

Foyer 2A (2nd floor), 3A (3rd floor) (Prague Congress Centre)

Board: 15

Poster A. Experimental Fusion Devices and Supporting Facilities P3 Poster session

Speaker

Subrata Pradhan (Institute for Plasma Research)

Description

Steady State Superconducting Tokamak (SST-1) at Institute for Plasma Research is a `working’ experimental superconducting device since late 2013. SST-1has been upgraded with Plasma Facing Components and is getting prepared towards long pulse operations in both circular and elongated configurations. Initial experiments have begun in SST-1 with circular plasma configurations. SST-1 offers a unique possibility of investigating long pulse discharges with large aspect ratio (> 5.5) compared to contemporary devices. Presently, SST-1 standard ohmic discharges are in excess of 100 KA with typical core density ~ 2 × 10¹⁹ 19 m^-3 -3 and core electron temperatures ~ 500 eV having duration in excess of 300 ms. A 42 GHz ECR pre-ionization source at ~ 150 KW in 1.5 T central field breaks down the gas, the current starts upat ~ 1.3 MA/s in 60-80 ms in an induced field of ~ 0.3 V/m. These standard discharges demonstrate copious saw teething and MHD activities as the pulse progresses including NTM, mode locking and MHD characteristics. PFC equipped SST-1 has completed these basic experimental studies confirmed with simulations. These includes eddy currents influencing the NULL dynamics, field errors, equilibrium index evolutions, wall influencing plasma characteristics, plasma positions, plasma rotational and Tearing Mode characteristics including the island width and island growths etc. Presently, SST-1 is attempting at multi second long high aspect ratio plasma discharges by coupling the Lower Hybrid with the Ohmic plasma as well as with robust real time position and density controls. The up-gradation details, salient early plasma characteristics in large aspect ratio PFC equipped SST-1 plasma and future experimental plans towards long pulse operations in SST-1 will be elaborated in this paper.