Preliminary study of supersonic molecular beam injection in ADITYA-U Tokamak

The first indigenously built ADITYA tokamak has been upgraded to ADITYA-U tokamak (R0 = 75 cm, a =25 cm), having feasibility of having shaped plasma operation with divertor coils. In ADITYA-U tokamak plasma breakdown is generated using hydrogen gas as a fuel and toroidal electric field produced with central solenoid Ohmic transformer coils. Toroidal magnetic field along with some other magnetic field is used to confine the plasma. Along with other issues related to operation of tokamak, fuelling is an important issue. We can fuel the tokamak by mainly three technologies such as Gas Puff, SMBI and Pallet Injection (PI). In ADITYA-U tokamak we are currently having Gas-Puff and supersonic molecular beam injection (SMBI) for fuelling Hydrogen gas in the vacuum vessel. In this paper the details of SMBI system installed in ADITYA-U tokamak along with the preliminary analysis of the data with SMBI discharges will be presented. (author)