Vorrichtung und Verfahren zum Betrieb eines Spektrometers mit Energie- und Winkelauflösung

In a device and process for imaging a beam of charged particles with a certain energy and angular distribution on a detector, using biased semi-transparent filter electrodes for forming a deceleration field and for energy selective transmission of the particles, a deflection system is provided to form, in the particle beam, parallel particle paths which have a mutual spacing corresponding to the angular distribution of the particles and which are directed onto the filter electrodes. Also claimed is a spectrometer provided with the above apparatus. Preferably, the deflection system comprises one or more deceleration lenses having deceleration potentials which increase in the particle beam propagation direction, the deceleration potentials of the deceleration lenses and the filter deceleration potential being set for imaging of electrons, ions, ion groups or charged atom or molecule groups.