Device for automatic recording of energy distributions of ions produced in field desorption

A device is described that generates a retarding potential and controls its delivery to an energy analyzer that is built into the ion source of an MI1201 mass spectrometer that has been refitted for field-desorption measurements. The emitter is a filament with a developed metal surface. The device is designed for automatic recording and accumulation of ion energy distributions, which permits determination of the ionization potentials of nonvolatile and thermally unstable substances with an error of +/- 0.15 eV.