Principles and Applications of a Dual Primary Ion Source and Mass Filter for an Ion Microanalyser

It is useful in some cases to filter the primary ion beam particularly when impurities are present in the primary beam. The primary ion beam from the duoplasmatron usually contains traces of non-desired ion species which may come from the feed gas or from the degassing of the source. In order to purify the primary ion beam from a duoplasmatron source, a magnetic mass filter has been designed for the CAMECA IMS 3F ion micro-analyser [1]. The features are: A symetrical magnetic mass filter which can mount two different ion sources.The ability to change rapidly between the duoplasmatron and cesium ion source which allows analysis of electropositive or electronegative elements in the same area.