Apparatuses and methods are provided for applying accelerated electrons to a gaseous medium by means of an electron beam generator, which has at least one cathode for emitting electrons and at least one electron exit window, wherein a) the at least one cathode is annular and the at least one electron exit window is in the form of an annular first hollow cylinder, the annular electron exit window in the form of the first hollow cylinder forms an inner wall of an annular housing of the electron beam generator, wherein the electrons emitted by the cathode are accelerated to the ring axis of the annular housing; b) an annular second hollow cylinder is arranged within the electron exit window in the form of the first hollow cylinder and delimits an annular space between the first hollow cylinder and the second hollow cylinder; c) a cooling gas is fed through the annular space between the first hollow cylinder and the second hollow cylinder; and d) the gaseous medium to which accelerated electrons are to be applied is fed through the second hollow cylinder.

A flood column for charged particle flooding of a sample, the flood column comprising a charged particle source configured to emit a charged particle beam along a beam path; a source lens arranged down-beam of the charged particle source; a condenser lens arranged down-beam of the source lens; and an aperture body arranged down-beam of the condenser lens, wherein the aperture body is for passing a portion of the charged particle beam; and wherein the source lens is controllable so as to variably set the beam angle of the charged particle beam down-beam of the source lens.

A flood column for charged particle flooding of a sample, the flood column comprising a charged particle source configured to emit a charged particle beam along a beam path; a source lens arranged down-beam of the charged particle source; a condenser lens arranged down-beam of the source lens; and an aperture body arranged down-beam of the condenser lens, wherein the aperture body is for passing a portion of the charged particle beam; and wherein the source lens is controllable so as to variably set the beam angle of the charged particle beam down-beam of the source lens.

A Schottky thermal field emitter (TFE) source integrated with a beam splitter by a standoff, which supports the beam splitter above the Schottky TFE extractor faceplate by a distance of 0.05 mm to 2 mm. The beam splitter includes a microhole array integrated with the standoff and being disposed opposite the extractor faceplate, the microhole array having a plurality of microholes that split the electron beam generated by the Schottky TFE into a plurality of beamlets. The support and extractor may be fabricated from the same material or from different materials. The support may be formed from a high temperature resistive material, which causes a potential difference between the extractor and the microhole array. This potential difference creates positively charged electrostatic lenses at the microholes, which increases current in the individual beamlets. Voltage on the microarray plate may be varied to achieve a high beamlet current.

A Schottky thermal field emitter (TFE) source integrated with a beam splitter by a standoff, which supports the beam splitter above the Schottky TFE extractor faceplate by a distance of 0.05 mm to 2 mm. The beam splitter includes a microhole array integrated with the standoff and being disposed opposite the extractor faceplate, the microhole array having a plurality of microholes that split the electron beam generated by the Schottky TFE into a plurality of beamlets. The support and extractor may be fabricated from the same material or from different materials. The support may be formed from a high temperature resistive material, which causes a potential difference between the extractor and the microhole array. This potential difference creates positively charged electrostatic lenses at the microholes, which increases current in the individual beamlets. Voltage on the microarray plate may be varied to achieve a high beamlet current.

An e-beam device includes a cold-field emission source to emit electrons and an extractor electrode to be positively biased with respect to the cold-field emission source to extract the electrons from the cold-field emission source. The extractor electrode has a first opening for the electrons. The e-beam device also includes a mirror electrode with a second opening for the electrons. The mirror electrode is configurable to be positively biased with respect to the extractor electrode during a first mode of operation and to be negatively biased with respect to the extractor electrode during a second mode of operation. The extractor electrode is disposed between the cold-field emission source and the mirror electrode. The e-beam device further includes an anode to be positively biased with respect to the extractor electrode and the cold-field emission source. The mirror electrode is disposed between the extractor electrode and the anode.

An e-beam device includes a cold-field emission source to emit electrons and an extractor electrode to be positively biased with respect to the cold-field emission source to extract the electrons from the cold-field emission source. The extractor electrode has a first opening for the electrons. The e-beam device also includes a mirror electrode with a second opening for the electrons. The mirror electrode is configurable to be positively biased with respect to the extractor electrode during a first mode of operation and to be negatively biased with respect to the extractor electrode during a second mode of operation. The extractor electrode is disposed between the cold-field emission source and the mirror electrode. The e-beam device further includes an anode to be positively biased with respect to the extractor electrode and the cold-field emission source. The mirror electrode is disposed between the extractor electrode and the anode.

An electron source according to the present disclosure includes a columnar portion made of a first material having an electron emission characteristic; and a tubular portion that is disposed to surround the columnar portion and made of a second material having a higher work function than the first material, wherein a hole that extends in a direction from one end face toward the other end face and has a substantially circular cross-sectional shape is formed in the tubular portion, and the columnar portion has a substantially triangular or substantially quadrangular cross-sectional shape and is fixed to the tubular portion in an abutting engagement with an inner surface of the hole.

An electron source according to the present disclosure includes a columnar portion made of a first material having an electron emission characteristic; and a tubular portion that is disposed to surround the columnar portion and made of a second material having a higher work function than the first material, wherein a hole that extends in a direction from one end face toward the other end face and has a substantially circular cross-sectional shape is formed in the tubular portion, and the columnar portion has a substantially triangular or substantially quadrangular cross-sectional shape and is fixed to the tubular portion in an abutting engagement with an inner surface of the hole.

An electron beam source including a cathode, an anode, a means for deflecting an electron beam over a target surface and at least one vacuum pump, the electron beam source further including a contraction area arranged between the anode and the means for deflecting the electron beam where a hole in the contraction area is aligned with a hole in the anode with respect to the cathode, a first vacuum pump is arranged between the contraction area and the anode and a second vacuum pump is arranged above the anode, a gas inlet is provided between the contraction area and the means for deflecting the electron beam, wherein a first crossover of the electron beam is arranged between the cathode and the anode and a second crossover is arranged at or in close proximity to the contraction area.