Real time monitoring of material erosion and deposition for the first wall using quartz crystal microbalance in EAST

The two QMBs with different distances from the plasma show complex and distinct erosion and deposition behavior. The QMB in the mid-plane H port closer to the plasma shows a relatively higher net erosion result with an average erosion rate of 1.34 ng/(cm2 s).

The normal discharges mainly contribute to the total net erosion and the maximum erosion amount reaches up to 110 ng/cm2 . Contrarily, a slight net deposition of 0.11 ng/(cm2 s) is obtained for the QMB in the mid-plane G port further away from the plasma and the erosion and deposition amount of most discharges are much lower due to lower particle flux. The disruptive discharges lead to a total net deposition rate of 0.48 ng/(cm2 s).