Research on measuring method of pumping speed for miniature sputter ion pump

Abstract

In this work, a new calibration apparatus, which employs the flowmeter method and the orifice method, was developed to get the low pumping speed of the miniature sputter ion pump (SIP), and the two methods were compared in the measurement of the low pumping speed. A low pumping speed of the order of 10-4 m3 s−1 was calibrated in the pressure range of 10-6 Pa to 10-2 Pa, and the combined standard uncertainty was 4.5–8.8% for nitrogen. The measurement results of the spinning rotor gauge (SRG) and the extractor gauge (IE514) were contrasted, and it can be found that the measurement error of the extractor gauge is obvious. Hence a method to measure the pumping speed and the outgassing rate of the extractor gauge is introduced, and the influence of the extractor gauge on the measurement was evaluated in the pressure range of 10-6 Pa to 10-4 Pa. The low pumping speed of the miniature SIP, which is a single-cylinder diode SIP, was calibrated in these high purity gases (N2, He, and Ar), and the flowmeter method performs better than the orifice method.