Abstract: An evacuated tube has a face plate and a tubular body with at least a portion of the body having a circular cross section. In the evacuated tube is an electron emissive electrode adapted to release electrons in response to impinging photons or photoelectrons, means for collecting the electrons and an anode. The electron emissive electrode is cup shaped, having an approximate circular top opening through which photons or photoelectrons enter to impinge on the electrode, a circular rim around the periphery of the top opening, and a side opening through which the electrons pass to exit from the electrode. The inside of the electrode is lined with electron emissive material.

Abstract: An electron discharge tube comprising a plenum having therein a photocathode, an anode, a plurality of spaced apart dynodes, each having an input aperture and an output aperture, the dynodes arranged so as to concatenate electron emissions from the photocathode to the anode, and a conductive mesh overlying each input aperture, is improved by providing non-uniform openings in the mesh whereby relatively greater electrostatic shielding is provided for the dynode surface proximate to the output aperture of a preceding dynode.

Abstract: A phototube includes a cup-shaped apertured electrode interposed between a substantially flat cathode and an electron collection electrode. Anapertured electrode is coaxially secured within the recess of the cup-shaped electrode in parallel spaced-apart facing relation to the cathode.

Abstract: An electron discharge tube comprises a photocathode, a dynode, a mesh having openings of non-uniform sizes on the dynode, and an anode, all in an evacuated tube. The mesh comprises a plurality of spaced first elongated elements of electrically conducting material and a plurality of spaced second elongated elements of electrically conducting material, intersecting to form openings of non-uniform sizes.

Abstract: Photoelectrons emitted from a flat photocathode are collected within an evacuated envelope by a surface of an electrode. The photoelectrons are accelerated by an electron lens system, as an electron stream, within an evacuated cavity between the photocathode and the electrode surface. The photoelectrons are accelerated through two succeeding cavity regions in which the electron trajectories associated with the electron stream are increasingly compressed. A cavity region of lessening compression of the electron trajectories associated with the electron stream is defined between the two cavity regions of increasing compression. The electrode surface is located closely proximate to the cavity region of greatest compression to collect a maximum number of the photoelectrons.

Abstract: Electron discharge device including a channel plate electron multiplier provided on its output face with a conducting layer of which substantially annular endspoiling segments extend a distance into the channels. The ends of the endspoiling segments are slanted in the same direction, and to at least the same degree of magnitude, as are the channels themselves with respect to the output face.