Abstract
Surface chemistry experimental end-station constructed at BL23SU at SPring-8 is widely used to study various surfaces and interfaces of functional materials by means of high-brilliance soft X-rays generated by synchrotron radiation. In order to analyze the surface chemical reactions between gas and solid surfaces in detail, an accurate control of flow rates of reaction gases is essential. In this paper, a computerized automatic gas flow control system to improve the accuracy and reproducibility of gas-surface reaction experiments in the pressure range of ultra-high vacuum (molecular flow) conditions is reported. The system uses feedback control to operate the slow-leak valve to control the pressure in the experimental apparatus. As a result, the system achieved results equivalent to those of a skilled experimenter. The system also enables the control of the pressure in the apparatus in a short period of time.
https://ror.org/01n09qc98 
