Time response of protection in event of vacuum failure based on Nude ionization gauge controller

This article describes the design and application of fast-response vacuum p rotection sensor module, based on the Nude ionization gauge and a homemade controller named GH07X. A simulative test indicated that the controller's r esponse time was less than 200 mus when 1 atm air rushed into the vacuum sy stem through a pulsed valve with 0.8 mm orifice nozzle and the emitting cur rent of the Nude gauge was 4 mA. The experiment result showed that the resp onse time mainly depended on the gas density as well as the electron emitti ng current of the Nude gauge filament. Compared with the vacuum protection sensors based on sputter ion pump and cold-cathode gauge, GH07X is faster a nd reliable besides, GH07X can be used as an ultrahigh-vacuum slow valve in terlock controller with response time of 100 ms, which is faster than other gauge controllers. The widely used field-bus interface CAN and common seri al interface RS232/RS485 are embedded in GH07X controller system. (C) 2001 American Institute of Physics.