Editing Ion source (section)

===Microwave-induced plasma===
Microwave induced plasma ion sources are capable of exciting electrodeless gas discharges to create ions for trace element mass spectrometry.<ref name="Okamoto1994">{{cite journal|last1=Okamoto|first1=Yukio|title=High-sensitivity microwave-induced plasma mass spectrometry for trace element analysis|journal=Journal of Analytical Atomic Spectrometry|volume=9|issue=7|date=1994|page=745|issn=0267-9477|doi=10.1039/ja9940900745}}</ref><ref name="DouglasFrench1981">{{cite journal|last1=Douglas|first1=D. J.|last2=French|first2=J. B.|title=Elemental analysis with a microwave-induced plasma/quadrupole mass spectrometer system|journal=Analytical Chemistry|volume=53|issue=1|date=1981|pages=37–41|issn=0003-2700|doi=10.1021/ac00224a011}}</ref> A microwave plasma has high frequency [[electromagnetic radiation]] in the [[GHz]] range. It is capable of exciting electrodeless [[gas discharge]]s. If applied in [[surface-wave-sustained mode]], they are especially well suited to generate large-area plasmas of high plasma density. If they are both in surface-wave and [[resonator mode]], they can exhibit a high degree of spatial localization. This allows to spatially separate the location of plasma generations from the location of surface processing. Such a separation (together with an appropriate gas-flow scheme) may help reduce the negative effect, that particles released from a processed substrate may have on the [[plasma chemistry]] of the [[gas phase]].