Puffing Rate Calibration and Application on EAST

The puffing system in fusion device plays an indispensable role in plasma density control and physical experiment.Moreover,the accurate control of puffing rate is very important for the experiment.The puffing ways of EAST device includes the ordinary puffing and Supersonic Molecular Beam Injection (SMBI). The ordinary puffing system is controlled by piezoelectric valve and the SMBI is controlled by pulse solenoid valve.It is found that the ordinary puffing rate is positively correlated with the voltage and pulse width of the piezoelectric valve.Under the same voltage,the larger the pulse width,the higher the inflation rate,but the inflation rate increases with the increase of the pulse width.Similarly,under the same pulse width,the higher the piezoelectric valve voltage,that is,the greater the valve opening,the higher the inflation rate,but the inflation rate increases slowly with the increase of voltage.By controlling the pulse width and piezoelectric valve voltage,the injection rate of ordinary puffing can be controlled more accurately.The SMBI pulse gas intake and feeding efficiency were also calibrated.Through the calibration of SMBI rate,it is found that the amount of deuterium atom injected by single SMBI pulse is about 2.9×10¹⁷,and the puffing efficiency of SMBI is 7%~15% under the condition of ohm discharge.The total number of feeding particles is calculated to be about 0.9×10²²under the condition of 100 second plasma discharge at 100 million degrees Celsius.This study provides data support for plasma density feedback control and other physical experiment.