THE STUDY ON DETECTION TECHNOLOGY OF TINY ION CURRENT FOR EXTREMELY HIGH VACUUM MEASUREMENT

In order to detect the extremely low ion current in ionization gauge when it is used to measure extremely high vacuum,a current-to-voltage conversion circuit equipped with low-pass filter,zero-point adjustment and phase compensation technology is designed in this paper,which can accurately measure the extremely low ion current about 10^-14 A. By verifying present circuit with different gauge type,it is found that the designed circuit can precisely detected the extremely low ion current generated in 10^-9 Pa.This circuit provides a technical reference for achieving extremely high vacuum equipment localization.