Abstract: This invention concerns a photo-cathode for a vacuum system, wherein the photo-cathode is configured for receiving electromagnetic radiation having an incoming wavelength and for emitting electrons in response thereto. The photo-cathode comprises a conducting structure having a geometry, the geometry comprising a tip section. The tip section is adapted to provide field enhancement, ?, when the conducting structure is illuminated with the electromagnetic radiation, wherein ? is greater than about 102. The photo-cathode further comprising a substrate, the substrate being or comprising a dielectric substrate, the substrate supporting the conducting structure.

Abstract: The present invention relates to an MCP unit or the like having a structure intended to achieve a desired time response characteristic, without depending on a limitation imposed by a channel diameter of MCP. The MCP unit comprises the MCP for releasing secondary electrons internally multiplied in response to incidence of charged particles, an anode arranged in a position where the secondary electrons reach, and an acceleration electrode arranged between the MCP and the anode. In particular, the acceleration electrode includes a plurality of openings which permit passing of the secondary electrons migrating from the MCP toward the anode. Further, the acceleration electrode is arranged such that the shortest distance B between the acceleration electrode and the anode is longer than the shortest distance A between the MCP and the acceleration electrode. Thus, an FWHM of a detected peak appearing in response to the incidence of the charged particles is remarkably shortened.

Abstract: The present invention relates to an MCP unit or the like having a structure intended to achieve a desired time response characteristic, without depending on a limitation imposed by a channel diameter of MCP. The MCP unit comprises the MCP for releasing secondary electrons internally multiplied in response to incidence of charged particles, an anode arranged in a position where the secondary electrons reach, and an acceleration electrode arranged between the MCP and the anode. In particular, the acceleration electrode includes a plurality of openings which permit passing of the secondary electrons migrating from the MCP toward the anode. Further, the acceleration electrode is arranged such that the shortest distance B between the acceleration electrode and the anode is longer than the shortest distance A between the MCP and the acceleration electrode. Thus, an FWHM of a detected peak appearing in response to the incidence of the charged particles is remarkably shortened.

Abstract: A MCP 1 according to the present invention is one in which outer circumferential glass 5 is disposed around channel glass 3 that is provided with a plurality of channels 7 in a long and thin hole shape and is formed in a plate shape. This channel glass 3 contains 35 to 55% of SiO2, 0 to 5% of Al2O3, 25 to 46% of PbO, 0.5 to 10% of &Sgr;(Li2O+Na2O+K2O), 0.1 to 8% of &Sgr;(Rb2O+Cs2O), 0 to 5% of &Sgr;(MgO+CaO+SrO+BaO), 0.1 to 7% of ZrO2, and 0 to 5% of Bi2O3 (all the above % are wt %). With such a composition, a sufficient glass network structure is formed in the channel glass 3. Moreover, the channel glass 3 can be sufficiently restricted from becoming porous, and moisture can be restricted from being adsorbed thereto. As results of these, a change with time, such as a “warp” can be sufficiently restricted from being generated even in a high-humidity environment.

Abstract: The present invention relates to an electron multiplier including a structure which effectively prevents an electric field from leaking to the front side of an MCP due to a voltage applied to the MCP, facilitates an operation of attaching/detaching the MCP, and prevents the MCP from being damaged and so forth during the operation. The electron multiplier includes an MCP as electron multiplying means, and an outer electric field shield member for accommodating the MCP. The electric field shield cap includes a body portion surrounding at least a side face of the MCP. The electron multiplier further includes a structure by which, while the MCP is held by the outer electric field shield member and an inner electric field shield member accommodated in the outer electric field shield member, the outer electric field shield member is attached to a base of the electron multiplier so as to facilitate the operation of attaching/detaching the MCP.

Abstract: In the microchannel 50, a conductive film 52 is formed on an electron input surface of a dynode 51 where the plurality of channels are arranged. The conductive film is made of material that can transmit light that has originated photoelectrons and that has a refractive index lower than that of the dynode constituting material.

Abstract: In the scanning electron microscope 10, the electron beam B is emitted to the specimen 2. When the electron beam B strikes the specimen 2, the specimen 2 reflects the electron beam as reflected primary electrons and generates secondary electrons. Those electrons are detected by the electron detector 14, which in turn produces a reflection image of the specimen 2. The electron multiplier 1 is used for this scanning electron microscope 10. The electron multiplier 1 includes the electron reflection plate 7 which receives the electron beam B when the electron beam B passes by or passes through the specimen 2. Upon receipt of the electron beam B, the electron reflection plate 7 reflects the electron beam B as reflected primary electrons and generates secondary electrons. The microchannel plate 3 is formed with a multiplicity of channels 31 for multiplying the reflected primary electrons and the secondary electrons.