The systematic Langmuir probe measurements for a weakly magnetized plasma have been carried out in the Linear Magnetized Plasma Device for different magnetic fields. By comparing the ion current density of probes with different sizes, the sheath thickness can be evaluated. It is found that while the ratio of cylindrical probe's dimension to ion Larmor radius is not more than 2, the model of probe for non-magnetized plasma is still applicable.
As an advanced fuelling method on tokamak, molecular beam injection （MBI） has successfully been developed in HL-1M firstly and applied to HL-2A later. Many advantages such as peaked density profile and the energy confinement time increasing have been found in the MBI experiments. Some interesting phenomena have been observed in the previous MBI experiments. But up to now the mechanism of the MBI seems not very clear.
SHI Zhongbing DING Xuantong YAO Lianghua LIU Zetian CHEN Chengyuan YANG Qingwei FENG Beibin ZHOU Yan YAN Longwen LIU Yi LIU Yong
