A HIGH-PRESSURE EXTERNAL ION-SOURCE FOR FOURIER-TRANSFORM ION-CYCLOTRON RESONANCE SPECTROMETRY

A new external high pressure ion source has been designed, constructed and successfully coupled to a Fourier transform-ion cyclotron resonance (FT-ICR) spectrometer. This instrument incorporates three stages of differential pumping, pulsed electron gun ionization, electrostatic ion optics and novel cylindrical decelerator lens. Theoretical aspects of ion transfer of externally generated ions to the ICR cell are discussed as are the physical characteristics of the decelerator lens. The nine orders of magnitude pressure differential between ion source and ICR cell permit the synthesis of extensively solvated ions whose chemistry can subsequently be examined in detail in the ICR cell. Several Examples of such chemistry are illustrated. © 1990.