Observation of bifurcation properties of radial electric fields using a heavy ion beam probe

摘要

The bifurcated nature of the potential profile of a toroidal helical plasma is investigated in CHS using a heavy ion beam probe. The measurements reveal that three main branches of potential Profile exist in ECR heated plasmas with a low density of n_e≈0.5×10_19 m ~3. The branches With higher central potential exhibit a rather strong radial electric field shear that should result in Fluctuation reduction and formation of a transport barries.