Method and apparatus for implementing an afterglow emission spectroscopy monitor

摘要

Afterglow spectroscopy allows observing light emission of gaseous species in absence of direct plasma light. This absence avoids the creation of a background spectrum obscuring weak emission from trace species. The invention describes a flowing afterglow version monitoring in-situ the cleanup of vacuum tools during pump/purge cycles. The invention also describes an intermittent afterglow version suitable for trace gas analysis at atmospheric pressure.