Abstract: A single-channel photomultiplier tube having a sealed envelope, of which one wall includes an internal face having a concavity with a central axis, turned toward the inside of the tube, having a plane of symmetry and containing a photocathode, inlet optics including electrodes, an electron multiplier including a plurality of dynodes, an anode, and a mechanism connecting the dynodes, the photocathode, electrodes of the optics, and the anode, at their respective operating voltages. The electron multiplier is composed of parts physically distinct from one another, and having between them a symmetry of revolution with respect to the central axis of the concavity.

Abstract: Single-channel photomultiplier tube (1) having a sealed envelope (4), of which one wall (5) comprises an internal face (7) having a concavity with a central axis (AA?), turned toward the inside of the tube, having a plane of symmetry and containing a photocathode (2), inlet optics (9) comprising electrodes, an electron multiplier (11) comprising a plurality of dynodes (30-39), an anode (16), means (12) for connecting the dynodes (30-39), the photocathode (2), electrodes (13, 15) of the optics (9), and the anode (16), at their respective operating voltages, characterised in that the electron multiplier is composed of parts (24, 26) physically distinct from one another, and having between them a symmetry of revolution with respect to the central axis of concavity.

Abstract: This invention relates to a photomultiplier tube including: a photocathode PK with a semi-transparent photo-sensitive layer provided to emit an electron flux towards the inside of the tube, focusing optics comprising a first dynode D1, concave on the side of the photocathode PK, and several Rajkman dynodes D3, . . . , D8 located on each side of a plane called the dynodes plane DP. According to the invention, the focusing optics also includes a second dynode D2 concave on the side of the re-emitting surface of the first dynode D1, the angle between the plane of the dynodes DP and the center line of the tube exceeding 45°, the concave side of the first Rajkman dynode D3 facing the re-emitting surface of the second dynode D2.