Thermal Ionization Mass Spectrometry
A thermal ionization mass spectrometer consists of four main systems: an ion source, a beam collimator, a magnet and a detector, along with various subsystems including vacuum pumps, power supplies and computers.
The ion source consists of one or more metal filaments that can withstand high temperatures such as rhenium, tantalum or platinum, on which the sample is loaded as a solid compound, with or without an activator. The sample is evaporated by increasing the temperature of the sample filament and ionized simultaneously, or vapor molecules are ionized by the significantly higher temperature of an ionization filament. Ionization is described by the Saha-Langmuir equation, which states that elements with a low ionization potential (Rb, Sr) are ionized at lower temperatures than elements with high ionization potential (Th, U). For some elements, such as Pb, the use of an activator is essential while for others, such as Os, the ionization potential