Presentation Information
[2P38]Toward development of a physicochemical-based pumping equation
*Wataru Osada1, Hajime Yoshida1 (1. National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology)
NMIJ has developed a metrological standard, traceable to SI base units, covering a wide pressure range including the UHV region down to 10−9 Pa. However, using a calibrated gauge does not resolve several long-standing issues in UHV technology. One of these is the difficulty of accurately predicting the pumping time required for a given UHV system. This issue essentially stems from the microscopic complexity of the pumping-down process, rather than from uncertainty in vacuum measurement. A pumping equation that accurately incorporates the physical phenomena involved in pumping-down, such as desorption and diffusion, would help address this issue. In this presentation, with a focus on the desorption-limited pumping process, I will discuss a direction for developing a physicochemical-based pumping equation.