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.

Abstract: An electron multiplier of the perforated sheet type includes two successive sheets constituting a dynode which has several multiplier channels in common. For controlling the gain of a given channel (A), a control electrode (30) is provided in the form of a sheet inserted between the sheets (14, 15) of a dynode (Dn) which has a grating window (33) controlling the gain of the channel (A) in question, and one (or several) aperture(s) (34) in accordance with the number of remaining channels. Another channel (B) is controlled by another electrode (31) inserted between the sheets (16, 17) of another dynode (D.sub.n+1). Also disclosed is a multi-channel photomultiplier tube which includes such an electron multiplier.

Abstract: A segmented photomultiplier tube having an electrode which, in its higher part acts as a focusing electrode for distributing photo-electrons on both sides of an axial plane, while in its lower part forming a collection cage, the photo-electrons undergo a first multiplication at the portions of the lateral walls, which are folded towards the axial plane. Apertures in a median plate of the electrode are covered by a highly transparent grid. The electrode is completed by a central partition which extends along the median plate just to the proximity of an input dynode of a laminated multiplier. A bar having a small cross-section may be provided, centered on the axial plane and receiving a potential near the potential across the photocathode. A plurality of these tubes can be arranged in a mosaic pattern for mapping luminous events.

Abstract: A photomultiplier tube in which a photoelectron beam (42) is divided in N independent paths by means of an electron-optical device. The optical device includes a first cup-shaped focusing electrode (25) having a flat bottom portion of polygonal or circular shape, in which N apertures (30a), (30b) are formed, and having raised side faces (28a), (28b) which extend towards the photocathode (12), viewed in the radial directions corresponding to the elementary photomultipliers, and side faces having V-shaped recesses between these directions. The optical device is completed by a deflection electrode (35) which is brought to approximately the same potential as the photocathode and which is centrally arranged close to the bottom portion of the focusing electrode (25). The assembly is followed by a multiplier (16) of the perforated sheet-type whose focusing electrode (161) has projecting portions (41a), (41b), the multiplier being followed by N anode plates (20a), (20b).

Abstract: A photomultiplier tube comprises a photocathode (10) deposited on an input window (20) sealed to one end of a sleeve (30), an input electrode (40), and an electron multiplier (50) with stacked dynodes. The input electrode (40) is constituted by a truncated cone conductor on the inside of which the electron multiplier (50) with stacked dynodes is deposited. A generator (61,62) of a material forming the photocathode (10) is advantageously placed in the space (70) situated between the input electrode (40) and the sleeve (30).

Abstract: A photomultiplier tube comprising a photocathode (10), focusing electrodes (12, 12') and a fast multiplier structure (20) having a large input surface relative to the photocathode and comprising at least one input dynode (21). According to the invention, said photomultiplier tube comprises, between the photocathode (10) and said focusing multiplier structure (20), a first multiplier stage (30) comprising, in succession and viewed from the assembly consisting of the photocathode (10) and the focusing electrodes (12, 12'), a grid (31), a first multiplier dynode (32) of the apertured-plate type, and an extracting grid (33) having the same pattern as said first multiplier dynode (32), the output of the extracting grid (33) being coupled to said input dynode (21) of the multiplier pattern by means of a focusing electrode (40).

Abstract: A photomultiplier tube (10) for the use in high collecting power is described having a photocathode (20), a first dynode (30) and a stackable-dynode multiplier device (40). According to the invention, the first dynode (30) is constituted by a sheet which extends parallel to the photocathode (20) and is provided with a feedthrough aperture (31), an extracting grid (32) being arranged between the photocathode (20) and the sheet, and the stackable-dynode multiplier device (40) is positioned opposite the aperture (30) in such a manner as to collect the secondary electrons (50) emitted by the first dynode (30) and passing through the feedthrough aperture (31).

Abstract: A reversible short circuit device in the form of a metal loop. The metal loop has a first base side which forms a first contact. Extending from the base side are second and third generally parallel sides. The second side includes a contact portion for engagement with an external object to provide an electrical connection therewith. The second and their sides are connected by a frangible fourth connection side. One of the second and third sides is subject to a recoiling force, which, when the connection side is interrupted or broken displaces the contact portion of the second side so as to reverse the short circuit. The short circuit device has particular application to photoelectric tubes to provide a means for interconnection of the tube components during manufacture, which may subsequently be reliably disconnected.

Abstract: An electron mulitplexer dynode (D) comprising two parallel disposed half-dynodes (d, d') to which an equal potential (V) is applied, and which are in the form of metal sheets (10, 20) in which apertures (11, 21) are formed. According to the invention, the second half-dynode (d'), called emitting half-dynode, has an electron surface (23), and the said emitting half-dynode (d') and the first half-dynode (d), called extracting half-dynode, are arranged so as to be staggered relative to each other.

Abstract: Photomultiplier tube (10) comprising a photocathode (20), a first cylindrical dynode (30), an electron multiplier device (40) of the "leaf" type, and a device (50) for coupling the first dynode (30) to the multiplier device (40). According to the invention, the said coupling device (50) consists, on the one hand, of a first electrode (51) composed of a cylindrical lateral plate (52) of axis parallel to that of the multiplier device and of an upper plate (53) pierced by an opening (54) for passage of the photoelectrons (21) towards the first dynode (30), and, on the other hand, of a second plane electrode (55) situated between the exit (32) of the first dynode (30) and the entrance (42) of the multiplier device (40).

Abstract: A photomultiplier tube which is insensitive to high magnetic fields comprises a photocathode deposited on a transparent window at the end of an insulating casing. The multiplier tube comprises a single amplifier stage comprising a dynode. The dynode is a metallic sheet with a circumference substantially surrounding the photocathode. A layer of a secondary emissive material is provided on the inner face of the dynode. An anode is formed of a metallic grid which is homeomorphous to the surface of the dynode. The anode is placed parallel to and at a short distance from the inside surface of the dynode.