Observations of SMBI penetration depth in the HL-2A tokamak with divertor configuration

The penetration depth of supersonic molecule beam injection (SMBI) is observed by using a set of detector array, which is composed of 22-channel Hα detectors, in the HL-2A tokamak with divertor configuration. The results show that there are two Hα emission peaks in the radial direction when the gas backing pressure is more than 1MPa, the second peak is localized at r/a-0.8, which indicates that there are still some hydrogen particles penetrating into the separatrix over 5cm even though more particles are dissociated or ionized at the edge plasma (SOL) region. (authors)