Performance of modified pulse-operated piezoelectric valves for the gas inlet system of RFX

This paper describes the tests aimed to characterize the modified piezoelectric valves installed in the gas injection system (GIS) of the RFX-mod machine. The behavior of the piezoelectric valves has been investigated after the modification of their duct geometry: the maximum driving voltage associated with the maximum repeatable flow rate, has also been evaluated. The results after approximately two years of machine operations with the new GIS are presented along with the flow rate versus the number of cycles.