| 摘要 |
A charged particle analyser for a spectrometer or microscope comprises: (a) a source used to irradiate a sample with electrons, X-rays or ions in order to make the sample release charged particles; (b) an electrostatic axis-symmetrical energy analyser (ASA) comprising coaxial equipotential surfaces; and (c) a charged particle detector, coaxial to the central axis of the ASA, and located close to analyser outlet. The inner and outer electrodes in the ASA are described by a cylindrical coordinate system according to the following formula: ~f = a.ln r - b.(r2/2 - Z2) (where, ~f = equipotential of the inner and outer electrodes; r = distance from rotation axis Z; Z = axial coordinates; and a, b = constants). The outer electrode has a negative voltage compared with a reference voltage for the inner electrode, and is used to analyse negatively charged particles. The inner electrode contains at least two circular holes coaxial with the central ASA axis. Charged particles with a range of different energies enter one of the holes, whilst the other hole separates charged particles having a pre-determined energy and whose trajectories extend in the direction towards the central ASA axis. |
