A Langmuir–Taylor detector, also called surface ionization detector or hot wire detector, is a kind of ionization detector used in

mass spectrometry Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a ''mass spectrum'', a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is used ...

, developed by John Taylor based on the work of Irving Langmuir and K. H. Kingdon.

Construction

This detector usually consists of a heated thin filament or ribbon of a metal with a high work function (typically

tungsten Tungsten (also called wolfram) is a chemical element; it has symbol W and atomic number 74. It is a metal found naturally on Earth almost exclusively in compounds with other elements. It was identified as a distinct element in 1781 and first ...

or rhenium). Neutral atoms or molecules that strike the filament can boil off as positive ions in a process known as surface ionization, and these may be either measured as a current or detected, individually, using an

electron multiplier An electron multiplier is a vacuum-tube structure that multiplies incident charges. In a process called secondary emission, a single electron can, when bombarded on secondary-emissive material, induce emission of roughly 1 to 3 electrons. If an ele ...

and particle counting electronics.

Applications

This detector is mostly used with alkali atoms, having a low ionization potential, with applications in

and

atomic clock An atomic clock is a clock that measures time by monitoring the resonant frequency of atoms. It is based on atoms having different energy levels. Electron states in an atom are associated with different energy levels, and in transitions betwee ...

References

Mass spectrometry Particle detectors {{analytical-chem-stub