electron ionisation


Also found in: Wikipedia.

electron ionisation

The process of molecular ionisation initiated by the interaction of a gas-phase molecule with an energetic electron. The beam of electrons is emitted from a heated metal filament in the source; the electrons are then accelerated through a potential difference of 70 V. The collision between the molecule and the electron causes ejection of an electron from the molecule (M), and produces a radical molecular ion with the unpaired electron (M•).
References in periodicals archive ?
Current ionisation methods: The use of 18 specified ionisation methods in mass spectrometry, namely atmospheric pressure chemical ionisation (APCI), atmospheric pressure photoionisation (APPI), chemical ionisation (CI), desorption chemical ionisation (DCI), desorption/ionisation on silicon (DIOS), direct analysis in real time (DART), electron ionisation (EI), electrospray ionisation (ESI), fast atom bombardment (FAB), field desorption (FD), field ionisation (FI), glow discharge (GD), inductively coupled plasma (ICP), ion attachment ionisation (IAI), matrix-assisted laser desorption ionisation (MALDI), negative ion electron capture (NIEC), thermal ionisation (TI), thermospray or other (more than 30 ionisation methods were identified in this market study).
Rez, Electron Ionisation Cross Sections for K, L, and M Shells, X-Ray Spectrosc.