Radiating divertor experiments in the HL-2A tokamak

Radiating divertor experiments have been performed in HL-2A using different fueling methods, such as direct gas puffing (GP), supersonic molecular beam injection (SMBI), and noble gas injection in divertor. The plasma temperatures at inner and outer target plates can be decreased below 2eV in completely detached plasma (CDP). Electron pressures at target plates, radiation power in divertor and the compression ratio (Rp0) of neutral gas pressures between the divertor and main chamber gradually drop during the detachment. Partial detachment first appears at inner target plate even if plasma density is very low. No clear high-recycling regime is observed before the detachment. It is more difficult to observe the partial detachment if the drift direction of magnetic field gradient is away from X-point because the electron temperature at inner target plate is higher than that at outer one.