Burle Technologies, Inc.

Rca Inc.

Charles M Tomasetti

Arthur F McDonie

Donald B Kaiser

Richard D Faulkner

Eugene D Savoye

David Roberts Winn

Fred A Helvy

Anita Sreepadraj Venkatarao

Scott C Moulzolf

Erich Burlefinger

Benjamin W Narehood

Charles B Beetz

John A Ulaky

Robert Caracciolo

Maurice D Harsh

Photomultiplier tubes with improved collection of incident radiation, especially from the periphery of the front face of the tube, and that more efficiently couple the collected radiation to the photocathode, and moreover have higher packing densities when assembled into arrays, resulting in enhanced imaging characteristics. The improvements in radiation collection and photomultiplier tube packing density are gained by a combination of several features including: tapering the edges of the faceplate so that the faceplate subtends an area as large or larger than any other cross-sectional area of the photomultiplier tube; forming the junction between the faceplate and metal tube on the underside of the faceplate, and in such a manner as to avoid obscuring the optical path between the incident radiation and photocathode; and utilizing the tapered edge of the faceplate as a reflector to couple radiation incident on the periphery of the faceplate to the photocathode.

Photomultiplier tube with improved light collection

A diamond transmission dynode and photocathode are described which include a thin layer of a crystalline semiconductive material. The semiconductive material is preferably textured with a (100) orientation. Metallic electrodes are formed on the input and output surfaces of the semiconductive material so that a bias potential can be applied to enhance electron transport through the semiconductive material. An imaging device and a photomultiplier utilizing the aforesaid transmission dynode and/or photocathode are also described.

Diamond transmission dynode and photomultiplier or imaging device using same

An electron flux amplifier is provided wherein a microchannel plate (MCP) is monolithically formed with, or bonded to, a semiconductor amplifier. In a preferred embodiment, microchannels are formed to extend into a semiconductor substrate to a predetermined depth from the surface, and a collection diode is formed in the substrate beneath the channels. The collection diode may comprise a single planar diode, or a plurality of electrically isolated diodes to provide for imaging of the electron flux. The electron flux amplifier may be used as a detector in a photomultiplier tube (PMT) having a photoelectronically responsive input surface and one or more accelerating electrodes for directing a photoelectron flux toward the electron flux amplifier.

Integrated semiconductor microchannel plate and planar diode electron flux amplifier and collector

A photomultiplier tube is disclosed having a first dynode array and a second dynode array oriented substantially orthogonal to the first dynode to provide a shortened profile. The first dynode array is preferably a box-and-grid dynode array and the second dynode array is preferably an in-line dynode array. A focusing electrode is positioned between the last dynode of the first dynode array and the first dynode of the second dynode array. The focusing electrode is constructed and arranged to facilitate the transfer of electrons emitted from the first dynode array to the second dynode array without generating secondary electrons.

Shortened profile photomultiplier tube with focusing electrode

A multiple section photomultiplier tube. The tube is constructed essentially as a matrix of several independent tubes in one envelope. The photocathode of each individual section of the tube is formed into an independent surface, and the photocathode to dynode spacings are isolated by a configuration built with separator electrodes which connect to photocathode boundary dividers formed in the faceplate. The boundary dividers also isolate the independent photocathode regions. The boundary dividers can be either slots into which the separator electrodes fit or ribs with which the separator electrodes are engaged.

Structure for a multiple section photomultiplier tube

A photomultiplier tube in which the a semiconductor photodiode serves as the anode and receives the electrons from the photocathode. The particular geometry for the focusing electrodes in the tube involves a two part structure with one part, the anode focus electrode, in close proximity to the semiconductor photodiode. The second part of the focus structure is a grid focus electrode with two different diameters, located approximately midway between the photodiode and the photocathode and operating on a low voltage. Together the electrodes create a focusing electric field so that the electrons from the large area photocathode are efficiently delivered to the small area of the semiconductor photodiode. The mounting of the photodiode is also designed to act as a termination to furnish superior timing characteristics.

Semiconductor anode photomultiplier tube

A focus electrode for an elongated hexagonal faceplate photomultiplier tube. The elongated hexagonal face plate and an off-center cage assembly are made to function properly in a photomultiplier tube by the use of a uniquely shaped asymmetric focus electrode. The focus electrode has a base which is a partial circle with two parallel chords and is constructed with a side wall around the perimeter of the base. The side wall has different heights above the two parallel chords of the base and slopes down to minimum but equal heights at points on the curved perimeter which are approximately at the center plane of the tube.

Focus electrode for elongated hexagonal photomultiplier tube

An imaging device includes a wafer of single crystal semiconductor material having a first surface with an input surfacing region which extends into the wafer from the first surface and a second surface with a charge storage portion which includes a plurality of discrete charge storing regions which extend into the wafer of the second surface. The wafer includes a potential barrier within the input signal sensing portion for controlling blooming. The wafer is improved by including a passivation region within the input sensing portion for stabilizing the energy level of the conductivity band of the minority carriers at the Fermi energy level of the semiconductor wafer. Additionally, an electrical leakage reduction region extends into the wafer from the second surface. The leakage reduction region is contiguous with each of the discrete charge storage regions.

Imaging device having improved high temperature performance

An electron discharge device includes an evacuated envelope having therein a photocathode, an anode and an electron multiplier. The electron multiplier comprises a plurality of dynodes having a nickel substrate, an exposed surface of which has a base layer of antimony sensitized with the vapors of a plurality of alkali metals. At least one Nichrome dynode, substantially devoid of secondary emissive material is disposed adjacent to the anode. The Nichrome dynode reduces and stabilizes the anode sensitivity and gain of the device.

Photomultiplier tube having a gain modifying Nichrome dynode

A method is described for stabilizing the anode sensitivity of a photomultiplier tube having a photocathode, an anode, and a plurality of dynodes including at least one Nichrome dynode adjacent to the anode. The steps include differentially heating the tube so that the temperature of the Nichrome dynodes and the anode is substantially greater than the photocathode. The temperature gradient established by the differential heating redistributes alkali material from the surface of the dynodes in a beneficial manner so as to balance the secondary emission gain of the dynodes so that decrease in Nichrome dynode gain is offset by increases in the gain of the other dynodes. The tube is then bright aged at a first voltage followed by a dark age at a higher voltage. The aging steps rearrange or rebind the remaining loosely bound alkali material to provide an increase in anode sensitivity stability.

Method for stabilizing the anode sensitivity of a photomultiplier tube

In a photomultiplier tube, antimony layers of a photocathode are prepared on a nickel substrate by providing a barrier layer of aluminum oxide between the substrate and antimony layers. The photocathode is subsequently exposed to the vapors of at least one alkali metal to sensitize the antimony layers. The aluminum oxide layer prevents alloying of the nickel with the antimony at processing temperatures in the range from 260.degree. C. to 285.degree. C. and provides a source of oxygen to oxidize the photocathode for increased photosensitivity, the oxidation time being a function of the thickness of the aluminum oxide layer. The photocathode is then exposed to cesium and may be superficially oxidized until substantially maximum photosensitivity is achieved.

Red sensitive photocathode having an aluminum oxide barrier layer

In a photomultiplier tube, antimony layers of a photocathode and a plurality of dynodes are simultaneously sensitized by exposure to the vapors of sodium and potassium at an initial temperature of less than about 120.degree. C. The temperature of exposure is gradually increased at a rate of less than about 10.degree. C. per minute until a final temperature of about 200.degree. C. is reached. Then, the photocathode and dynodes are baked at the final temperature until substantially maximum photosensitivity is achieved. The photocathode and dynodes are thereafter exposed to cesium and may be superficially oxidized until substantially maximum photosensitivity is achieved.

Method of sensitizing electron emissive surfaces of antimony base layers

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.

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Leola, PA, United States of America

Charles M Tomasetti