Experimental Study of the Ohmic Density Limit in HL-1M

Density limit investigations have been performed under a variety of discharge conditions on HL-lM, including hydrogen isotope, silicon wall coating and a variety of fuelling methods (gas puff, pellet and supersonic molecular beam (SMB) injection). Detailed analysis shows that the HL-lM density limit is a disruptive limit and it is related to first wall recirculating and fuelling methods. The destruction of balance between radiation and input power is the main reason for the density disruption.