Abstract: The present invention concerns an imaging energy filter for electrically charged particles with a toroidal energy analyzer, preferably with a hemispherical analyzer, with an entrance plane and an exit plane. To provide an imaging energy filter and a spectroscope having such an imaging energy filter, which has a higher degree of position and angle resolution and which can be operated with a greater acceptance angle, it is proposed according to the invention that a mirror element for electrically charged particles is provided and is so arranged that charged particles which leave the toroidal energy analyzer by way of the exit plane are reflected back into the toroidal energy analyzer by the mirror element so that the charged particles pass through the toroidal energy analyzer a further time in the opposite travel direction.

Abstract: The present invention concerns an imaging energy filter for electrically charged particles with a toroidal energy analyser, preferably with a hemispherical analyser, with an entrance plane and an exit plane. To provide an imaging energy filter and a spectroscope having such an imaging energy filter, which has a higher degree of position and angle resolution and which can be operated with a greater acceptance angle, it is proposed according to the invention that a mirror element for electrically charged particles is provided and is so arranged that charged particles which leave the toroidal energy analyser by way of the exit plane are reflected back into the toroidal energy analyser by the mirror element so that the charged particles pass through the toroidal energy analyser a further time in the opposite travel direction.

Abstract: The invention relates to an energy filter image generator for filtering electrically charged particles. The inventive energy filter comprises at least two toroidal energy analysers (30, 40) arranged one inside the other. A transfer lens device (20) is disposed between the plane of emergence (5) of the first energy analyser (30) and the plane of incidence of the second energy analyser (40), thereby making it possible to obtain the perfect energy filtered reproduction of the surface (1?) of a sample on a detector (10).

Abstract: The invention relates to an energy filter image generator for filtering electrically charged particles. The inventive energy filter comprises at least two toroidal energy analysers (30, 40) arranged one inside the other. A transfer lens device (20) is disposed between the plane of emergence (5) of the first energy analyser (30) and the plane of incidence of the second energy analyser (40), thereby making it possible to obtain the perfect energy filtered reproduction of the surface (1?) of a sample on a detector (10).