Realization and measurement method of UHV/XHV condition

摘要

Curent technologies to establish UHV andXHV conditions and present methods to measure UHV/XHVconditions were summarized and discussed. From the viewpoint of UHV/XHV genetarion, the importance ofcontrolling outgassing from vacuum chambers was firstexplained based on the equation of evacuation. Thenseveral methods effective to reduce the outgassing ratewere introduced. Those methods are application ofelectrochemical polishing, vacuum pre-baking, BN andTiN coating on SUS, and also the adoption of othermaterials than SUS such as aluminum and copper. Theoutgassing from pumping system and also the reduction of it were also discussed.As to UHV/XHV measurement, several principal problemsassociated with XHV measurement were first discussed,which were followed by the introduction of new XHVgauges and new measurement methods developed to overcome those problems.