Abstract: An electron source particularly for a RHEED measurement system or a RHEED measurement system as such includes an electron emitter (5), a first deflection stage (6a, b) for radiating an electron beam onto a sample (1), and a second deflection stage between the first stage (6a, b) and the sample 1, preferably near the sample.

Abstract: An electron source particularly for a RHEED measurement system or a RHEED measurement system as such includes an electron emitter (5), a first deflection stage (6a, b) for radiating an electron beam onto a sample (1), and a second deflection stage between the first stage (6a, b) and the sample 1, preferably near the sample.

Abstract: A device for imaging a beam of particles composed of charged particles with a certain energy and angle distribution on a detector device using a device, including a deflection unit with at least one deceleration lens provided for forming essentially parallel particle paths in the particle beam, whose reciprocal distances correspond to the angle distribution of the particles, and a filtering unit, which is located between the deflection unit and the detector facility, whereby the filtering unit may be biased with a potential for formation of a braking field and is adapted to be energy-selectively permeable for the particles, on the sample side before the deflection unit, an entry window in the form of an axial-symmetrical staged aperture or an entry grid is located, which is electrically separated from the deflection unit and at ground potential.

Abstract: An apparatus and method for imaging on a detector a particle beam of charged particles having a distinct energy distribution and a distinct angle distribution. The apparatus has deflectors which are provided to create in the particle beam essentially parallel particle paths spaced to correspond to their original angle distribution. The deflectors also direct the particle beam to semi-transmissive, aligned filter electrodes, which produce a potential difference to create a deceleration field to allow the particles to pass through by means of energy selectivity.