Radioactivity Nickel, Americium, and Tritium

Radioactive sources are favored for use in IMS analyzers because they provide stable and reliable operation, with ionization chemistry that is well suited for most current applications of IMS. Furthermore, radioactive foils do not require an external power supply and have no moving parts or maintenance requirements. At present, the most widely used and best understood of all ion sources for IMS is still the long-favored radioactive i source, which is also widely used in electron capture detectors (ECDs) for gas chromatography (GC). The preferred radioactive source is 10 mCi (3.7 10 Bq) of Ni coated as a thin layer on a metal strip, generally nickel or gold. The maximum energy of the electrons emitted from the Ni source 

Summary of Ionization Techniques Used in Ion Mobility Spectrometry 

Ion Source Type of Chemicals Maintenance Cost Comments 

Corona discharge Universal High Medium Eleclrode 

Photoionization Selective Medium Medium r lacement required Low efficiency 

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