Development of a novel mass spectrometer equipped with an electron cyclotron resonance ion source

The ionization efficiency of an electron cyclotron resonance ion source (ECRIS) is generally high and all elements can be fundamentally ionized by the high-temperature plasma. We focused our attention on the high potentiality of ECRIS as an ion source for mass spectrometers and attempted to customize a mass spectrometer equipped with an ECRIS. Precise measurements were performed by using an ECRIS that was specialized and customized for elemental analysis. By using the charge-state distribution and the isotope ratio, the problem of overlap, such as that observed in the spectra of isobars, could be solved without any significant improvement in the mass resolution. When the isotope anomaly (or serious mass discrimination effect) was not observed in ECR plasma, the system was found to be very effective for isotope analysis. In this paper, based on the spectrum (ion current as a function of an analyzing magnet current) results of low charged state distributions (2+, 3+, 4+,...) of noble gases, we discuss the feasibility of an elemental analysis system employing an ECRIS, particularly for isotopic analysis. The high-performance isotopic analysis obtained from an ECRIS mass spectrometer in this study suggests that it can be widely applied to several fields of scientific study that require elemental or isotopic analyses with high sensitivity.