Beam deflection, early instruments

The first time-of-flight mass spectrometers used electron impact (El) ionization, so that the need for accomodating continuous ionization sources was recognized from the beginning. Many of these early instruments utilized beam-deflection techniques " to admit a narrow initial ion packet into the flight tube. Later, Pinkston et al. " utilized beam deflection in an E-TOF (where E is an electrostatic energy... 

Recent advances in far I.R. instrumentation have been mainly in the area of detector improvement. Detection in the far I.R, is restricted to bolometric detection as opposed to the availability of photo conductive detection at wavelengths shorter than about 30 pm. An early standard for far I.R. detectors was the Golay bolometer detector. The periodic heating and cooling of a chopped I.R. beam is translated into expansion contraction of a small pocket of gas which in turn deflects a membrane. The membrane deflection is measured electro-optically and converted to the corresponding signal. 

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