Editing Ion source (section)

====Fast atom bombardment====
{{Main|fast atom bombardment}}
Particle bombardment with atoms is called fast atom bombardment (FAB) and bombardment with atomic or molecular ions is called [[secondary ion mass spectrometry]] (SIMS).<ref name="WilliamsFindeis1987">{{cite journal|last1=Williams|first1=Dudley H.|last2=Findeis|first2=A. Frederick|last3=Naylor|first3=Stephen|last4=Gibson|first4=Bradford W.|title=Aspects of the production of FAB and SIMS mass spectra|journal=Journal of the American Chemical Society|volume=109|issue=7|date=1987|pages=1980–1986|issn=0002-7863|doi=10.1021/ja00241a013|bibcode=1987JAChS.109.1980W }}</ref> Fission fragment ionization uses ionic or neutral atoms formed as a result of the [[nuclear fission]] of a suitable [[nuclide]], for example the [[Californium]] isotope <sup>252</sup>Cf.

In FAB the analytes is mixed with a non-volatile chemical protection environment called a [[Matrix Isolation|matrix]] and is bombarded under vacuum with a high energy (4000 to 10,000 [[electron volts]]) beam of atoms.<ref name="pmid7306100">{{cite journal |vauthors=Morris HR, Panico M, Barber M, Bordoli RS, Sedgwick RD, Tyler A | title = Fast atom bombardment: a new mass spectrometric method for peptide sequence analysis | journal = Biochem. Biophys. Res. Commun. | volume = 101 | issue = 2 | pages = 623–31 | date = 1981 | pmid = 7306100 | doi =10.1016/0006-291X(81)91304-8 }}</ref> The atoms are typically from an inert gas such as [[argon]] or [[xenon]]. Common matrices include [[glycerol]], [[thioglycerol]], [[3-nitrobenzyl alcohol]] (3-NBA), [[18-crown-6]] ether, [[2-nitrophenyloctyl ether]], [[sulfolane]], [[diethanolamine]], and [[triethanolamine]]. This technique is similar to secondary ion mass spectrometry and plasma desorption mass spectrometry.