Abstract: A projection lens assembly (10) projects onto a display screen (38) electrons emitted from an output side (86) of an electron multiplier such as, for example, a microchannel plate (70). The projection lens assembly includes a dome-shaped mesh element (16) that is concave as viewed from the display screen. The mesh element is positioned between the microchannel plate and a filter element (20) having a beam-limiting aperture (22). The mesh element is of an aspherical shape that allows the projection lens assembly to project the electrons toward the display screen with substantially no spherical aberration, thereby forming near the beam-limiting aperture an electron beam crossover of small diameter. The beam-limiting aperture is formed with a relatively small diameter that allows the filter element to block electrons of energies outside a preselected range of energy values, thereby reducing chromatic aberration in the image formed on the display screen.

Abstract: A microchannel plate device utilizing a semiconducting bulk material is cacterized by electron emissions of high output current density and efficiency. The channel passages in the plate device which are square in cross-section accommodates a larger open area ratio at the input and output plate surfaces. An extended range of high electron emission applications for the plate device is provided. Such applications may include a photocathode installation to which a modulation pulse input is applied under low voltages isolated from high post-accelerating voltages.

Abstract: A channel electron multiplier phototube having a channel electron multiplier, a transparent faceplate, and an anode assembly. The channel electron multiplier includes an insulating body having a curved passageway extending therethrough. A photoemissive element, and a secondary emissive dynode material is on the walls of the passageway. The passageway, together with a photoemission film of the photocathode assembly and the anode of the anode assembly define an evacuated closed region. Preferably, the electron multiplier is a monolithic ceramic body.

Abstract: A mount for attaching an electrode system, which focusses electrons generated upon the incidence of x-rays on an input luminescent screen onto an output luminescent screen, to an exterior housing of the intensifier is formed by annular electrodes which telescopically engage and which are held together at overlapping regions by a clamped connection. The mount has a simple structure which minimizes the possibility of the electrode system getting out of adjustment, and also significantly decreases the assembly time during manufacture of the x-ray image intensifier.

Abstract: Microchannel plates (MCPs) and channel electron multipliers (CEMs) having channels etched by a directionally applied flux of reactive particles are disclosed. The channels are activated with thin film dynodes. Various embodiments including monolithic and stacked devices are disclosed. Activation of the channels is achieved by various techniques including CVD, LPD and native growth by oxidation.

Abstract: A segmented electron multiplier is disclosed with front and rear sections. The sections are specially designed so that the length of the rear section compared to the length of the front section is no less than 4:1. This permits multiple replacements of the rear section, after the multiplier wears out, without any unsatisfactory drop in the overall electrical gain produced by the repaired device. In the preferred embodiment, the front portion is a funnel having a tubular stem, and the rear portion is a straight tube with a cylindrical helical inner channel. The length-to-length split is 5:1, which theoretically permits up to six or seven replacements of the rear section before unsatisfactory gain occurs.

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: An electron tube comprising a stack of at least one perforate plate-shaped insulating element and at least one perforate plate-shaped metal electrode structure, the insulating element comprising a core and being provided with an aluminium layer at least on a side facing the electrode structure, at least the outer layer of the aluminium layer being oxidized, and the coefficients of thermal expansion of the core and the electrode structure being at least substantially equal. In this manner, the thermal stresses occurring between the insulating element and the electrode structure during firing are reduced, so that the risk of their displacement relative to each other is reduced.

Abstract: A simultaneous positive and negative ion detector including a microchannel plate having segments which are biased to attract positively and negatively charged particles.

Abstract: An ion detector in which conversion dynode means are placed near a microchannel plate means for receiving and amplifying converted ions.

Abstract: Reduced ion feedback in an electron multiplier (EM) is achieved by applying a higher than normal bias voltage to the EM and degassing the EM with a relatively high concentration of self-generated particles as a result of the applied bias voltage.

Abstract: A channel electron multiplier phototube having a channel electron multiplier, a photocathode assembly, and an anode assembly. The channel electron multiplier includes an insulating body having a curved passageway extending therethrough. A secondary emissive dynode material is on the walls of the passageway. The passageway, together with a photoemission film of the photocathode assembly and the anode of the anode assembly define an evacuated closed region. Preferably, the electron multiplier is a monolithic ceramic body.

Abstract: Scanning electron microscopy apparatus employing a detector to detect emission of electrons resulting from the impingement of electrons of an electron beam on an object being viewed, the apparatus including an electron beam source providing the electron beam, a magnet providing a magnetic field to direct the electron beam to the object, a first microchannel plate having a first hole through it aligned with the electron beam, a first surface directed toward the electron beam source for receiving low energy electrons that have been emitted from the object and directed through the hole by the magnetic field, a second surface on the opposite side of side first microchannel plate for discharge of multiplied electrons, and a first anode facing the second surface, the first anode being positioned to collect electrons discharged from the second surface.

Abstract: Channel electron multipliers, including microchannel plates, with alternating layers of deposited conductive and insulative material, the conductive material and insulative material having, at holes therethrough in registry, secondary emission coefficients respectively of greater than one and less than one.

Abstract: A method is provided for depositing a conducting electrode on the output face of a microchannel plate and into the output end of each channel. The electrode is vapor deposited by a method which ensures that the material impinges on the output face from random angles relative to the axis of each channel. A layer (10) of tapering thickness is formed down each channel. When used in an image intensifier tube, for example, the output beam of electrons from each channel is more collimated and the resolution of the tube is improved.

Abstract: Photomultiplier dynodes (D.sub.1, D.sub.2 . . . ) each comprise two spaced planes (D.sub.11 and D.sub.12) made up elementary laminations having a cross-section in the form of an isosceles triangle which is symmetrically disposed relative to the inlet window of the photomultiplier tube. The laminations in the two consecutive planes of a single dynode stage are offset relative to each other to constitute a baffle, and are disposed in such a manner that electrons leaving the first plane pass through the second plane without striking the laminations thereof. The distance Z.sub.1 between two dynode stages is large relative to the distance Z.sub.O between the two planes of a single dynode, and is chosen as a function of the electric field in such a manner that the secondary electrons from the upstream stage strike a limited number of the laminations in the downstream stage with a concentrated distribution.

Abstract: A color display tube which has a channel plate electron multiplier for multiplying a low voltage, low current electron beam and thereby obtaining an amplified output beam for producing an image on a screen formed of a plurality of different phosphors arranged as dots, each of which is surrounded by at least one ring. In order to form the output beam into well defined dots and rings to obtain good color purity, the source-to-screen distance of the output beam is varied in a predetermined manner. A means for doing this comprises additional electrodes mounted on the output side of the electron multiplier.

Abstract: A method is provided for bonding glass channel plates (1,8) together in a stack, with the channels (2) of one plate being at an angle to the channels (9) of an adjacent stack to reduce optical and ion feedback. A layer of indium (4,10) is provided on plate faces to be bonded, bonding being achieved by applying pressure and a temperature between 130.degree. C. and 350.degree. C. A mechanically rigid and electronically stable channel plate electron multiplier is obtained for use in particle or photon counters or in raster intensified cathode ray tubes.

Abstract: A color display system including a cathode ray display tube (10) of the kind which has an electron multiplier (16) arranged adjacent a luminescent screen (14) comprising a repeating pattern of three different color phosphor elements and pairs of color selection electrodes (38, 40) associated with each channel of the multiplier operable to control the direction of the electron beam from the channels for color selection purposes uses a switching bridge circuit comprising semiconductor switching device (52, 54, 56, 58), e.g. MOSFETs, connected between voltage supplies for switching the voltage applied to each one of the pair of electrodes between three respective levels in synchronism to achieve a predetermined color selection sequence. The semiconductor devices are controlled by synchronized waveforms from a pulse generating circuit (86) via optocouplers (88) enabling the switching bridge circuit to be floated at a high potential.

Abstract: A charged particle detector comprises a micro-channel plate for detecting charged particles secondarily generated from a specimen irradiated with a narrowly defined beam of charged particles, a signal outputting circuit for transmitting therein a signal detected by the micro-channel plate and then outputting the signal, and a processing circuit for simultaneously outputting signals of secondary charged particles generated from the specimen at the same instant of time. Preferably, the processing circuit is constructed by a vortex-shaped electrode or the combination of concentric electrode segments and delaying elements.

Abstract: In one voltage-driven embodiment, a high spatial resolution two-dimensional array of bistable completely cross-talk free light modulation elements is constituted as a lamination of an input two-dimensional photoconductor thin film layer and an output two-dimensional electroluminescent phosphor thin film layer disposed in etched wells individually defined in corresponding cores of the optical fibers of a fiber optic face plate. In another voltage-driven embodiment, a very low cost high spatial resolution 2-D array of bistable substantially cross-talk free light modulation elements is constituted as a lamination of a photoconductor thin film layer, a selectively dimensioned and apertured opaque masking thin film layer, and an electroluminescent phosphor thin film layer.

Abstract: In one voltage-driven embodiment, a high spatial resolution two-dimensional array of bistable completely cross-talk free light modulation elements is constituted as a lamination of an input two-dimensional photoconductor thin film layer and an output two-dimensional electroluminescent phosphor thin film layer disposed in etched wells individually defined in corresponding cores of the optical fibers of a fiber optic face plate. In another voltage-driven embodiment, a very low cost high spatial resolution 2-D array of bistable substantially cross-talk free light modulation elements is constituted as a lamination of a photoconductor thin film layer, a selectively dimensioned and apertured opaque masking thin film layer, and an electroluminescent phosphor thin film layer.

Abstract: Electron multiplier element for secondary emission, consisting of a first metal plate (11) which has at least one multiplier hole (12) having one input aperture (13) and one output aperture (14), and a second metal plate (16) in parallel with the first plate (11) which has at least one auxiliary hole (17) disposed opposite the output aperture (14) of the multiplier hole (12). The second plate (16) being brought to an electric potential (V1) which is higher than the electric potential (V0) of the first plate. The apertures (13, 14) are such that the projection (18) of the output aperture (14) of the multiplier hole (12) in a plane which is parallel to the first metal plate (11) is at least partially located outside the corresponding projection (19) of the input aperture (13).

Abstract: In a display tube a laminated dynode channel plate electron multiplier (16) produces at its channel outputs (50) a current-multiplied beam (34) in response to an electron beam being scanned thereover which is accelerated towards a phosphor screen (14) comprising repeating groups of different color phosphor elements and selectively directed onto particular elements by color selection deflector electrodes (38,40) adjacent the channel outputs. To provide increased horizontal resolution capability the exits (50) of the apertures in the final dynode are elongate in shape, other dynodes having circular apertures, and arranged parallel to one another with their longer axes extending vertically to form a comparatively narrow horizontal width output beam. The final dynode aperture entrances may be similarly elongate or circular with the apertures having a re-entrant profile.

Abstract: A method for production of channel plate from sheet material having secondary emission yield after firing. According to the method, a plurality of parallel ribs are formed on the sheet. Then at least two layers of sheet are arranged one over the other by stacking in such manner that each rib element extends in the same direction, or the sheet is rolled into a spiral form which can be cut into channel plates. The stacked or rolled sheet material is then fired so as to adhere the surfaces of the ribs to the surfaces of the adjacent sheet to form the channel plate. In the particular embodiment disclosed herein, the sheet is rolled in the longitudinal direction of the ribs and the spiral body is cut into sector like pieces. After firing, electrodes are formed onto opposed end surfaces including end surfaces of each rib.

Abstract: A channel electron multiplier having a semiconductive secondary emissive coating on the walls of said channel wherein said electron multiplier is a monolithic ceramic body and said channel therein preferably is three dimensional.

Abstract: New fiber optic elements and a new microchannel plate for proximity focus image intensifier tubes and a method for making them are provided. Higher resolution is provided at the center of the field of view by the use of graded fiber and channel sizes and by the use of convex and concave surfaces in proximity focus.

Abstract: In a cathode ray display tube having a glass faceplate carrying a screen thereon including a screen electrode and an electron multiplier disposed adjacent the screen for current-multiplying an electron beam directed onto the screen, a low profile termination arrangement for establishing electrical connection with the screen electrode and a multiplier electrode comprises respective, spaced, thick film conductive tracks on the inner surface of the faceplate and bordering the screen connected at lead-in portions thereof with conductor means, e.g. conductive epoxy, in apertures extending through the faceplate via metal sealing discs.

Abstract: A flat cathode ray display tube has an envelope divided into front and rear portions by a partition carrying frame deflection electrodes with an electron gun (30) and line scanning deflector positioned in the rear portion, the electron beam being directed initially parallel to a flat faceplate of the envelope, turned through 180.degree. by a reversing lens into the front portion and then deflected by electrodes towards a screen on the faceplate. In addition to the electrodes, other components are also mounted on the partition forming a sub-assembly whereby correct mutual positioning is ensured and assembly facilitated. A spacing structure accurately spaces the sub-assembly from the faceplate and supports also an electron multiplier for beam current amplication.

Abstract: In a flat cathode ray display tube having an electron gun adjacent a rear wall of the tube's envelope which produces an electron beam travelling across the rear wall before being turned in the opposite direction and then deflected onto a screen carried by faceplate opposite the rear wall, getter means is situated in one or more recesses, each defined at least in part by an elongate rib formed in the rear wall, e.g. by pressing, with the recess wall shielding the getter means directly from the gun to prevent contamination. The rib serves also to strengthen the rear wall. A line scanning deflector is similarly shielded.

Abstract: A canal structure of an electron multiplier, especially for an X-ray image intensifier, comprises several perforated metal dynodes which emit secondary electrodes and between each of which a plate-shaped separating element of electrically insulating material with an at least largely regular hole pattern is arranged. This canal structure has a relatively simple design, in which undesirable charging up at the separating elements is prevented to a large degree. The metal dynodes are realized as impingement dynodes of thin perforated foils or screens or nets or grids, where at least four holes each fall on the area occupied by a canal-like hole of the plate-shaped separating element. The plate-shaped separating elements have a comparatively greater thickness than the thickness of the perforated foils or screens and have on their upper and lower flat sides a layer of electrically highly conductive material and have at their hole walls a layer of an electric resistance material.

Abstract: Electron multiplier plate with controlled multiplication, multiplier element comprising the said plate, multiplier device comprising the said element and application of the said device to a photomultiplier tube.Secondary emission electron multiplier plate (10) of the "aperture plate" type, comprising multiplier apertures (11), each having an input side (12), an output side (13), and an efficacious multiplier partition (14) having emissive power. Multiplier plate (10) has at least one elementary multiplier pattern (15) comprising a plurality of multiplier apertures, at least the said efficacious multiplier partitions (14a) of the peripheral multiplier apertures (11a) of the pattern (15) being oriented towards the interior of the said pattern.

Abstract: A channel plate electron multiplier is mounted parallel to, but spaced from, the screen. The electron multiplier comprises a stack of juxtaposed substantially planar apertured dynodes with the apertures therein aligned to form channels. An apertured extractor electrode is mounted on the output side of the electron multiplier. Preferably two or more foraminous deflector electrodes are mounted on the extractor electrode. The apertures in the foraminous deflector electrodes have the same pitch as the channels of the electron multiplier but are offset laterally relative to each other and to the axes of the channels by amounts which allow the emergent electron beam from each channel to pass through to the screen without impinging upon the deflector electrodes. By applying a potential difference between the deflector electrodes an electron beam emerging from its respective channel is deflected laterally onto a respective one of its associated group of phosphor stripes.

Abstract: A microchannel plate with a plurality of microchannel portions, a portion in an amplifying direction from another portion having a lower surface zone resistance than the other, materials and circuitry being provided to permit controlled higher-temperature operation.

Abstract: A microchannel plate (MCP) tube comprises a photocathode on the MCP input electrode in addition to the conventional semitransparent cathode on the input window of the tube. The second cathode results in additional light being converted into photoelectrons. It also causes secondary emissions of the photoelectrons already generated at the tube window. These phenomena result in higher gain and signal-to-noise ratios for the tube. The second photocathode can employ a coating which is unstable in air to chemically combine with ions traveling in the backstream direction which would otherwise damage the cathode on the tube input window. Its construction can also be such as to function effectively as a trap or "getter" for neutral particles traveling back towards the input window.

Abstract: An electron multiplier includes a micro-channel plate (12) having secondary electron emission. The channel plate is fitted in an annular metal frame (16, 17) which is in direct electrical contact with one (13) of the metallizations (13, 14) on the faces of the channel plate. The frame constitutes the means to apply an electric potential to one of the faces of the channel plate. The means to apply an electric potential to the other face of the channel plate are constituted by metallic contact studs (25) fixed in an insulated manner on the metallic frame and connected to the metallization (14) of the other face by means of conductor wires (30). The multiplier is incorporated in a detector device, the frame being soldered to the body (45) of the device by means of rods (48) traversing the body and soldered thereto.

Abstract: A channel secondary electron multiplier has a mechanically sturdy body made of metal or ceramic material. The body forms an internal multiplier channel having a curved, e.g. helical main portion and a funnel shaped entrance end. A resistive layer forming a secondary electron emissive surface is provided on the inner wall of said channel inclusive that entrance end. The secondary electron emissive resistive layer in said funnel shaped entrance end has the form of a spiral-shaped band or stripe having a width which is preferably at least approximately equal to the circumferential dimension of the main portion of said channel. The body has a thermal coefficient of expansion which is at least 15% larger than the thermal coefficient of expansion of said layer, to maintain said layer under compression.

Abstract: Electron multiplier element (11) with secondary emission of the "apertured plate" type, characterized in that, on the one hand, it consists of a first plate (12) having holes (13), which are termed multiplier holes, in which each multiplier hole (13) defines on a first surface (14) of the said first plate (12) an aperture (15) which is termed input aperture and which is larger than the aperture (16), which is termed output aperture, which is defined on the second surface (17) of the first plate (12), and, on the other hand, consists of a second plate (22) which is parallel to the first plate (12), which also comprises holes (23) which are termed auxiliary holes the aperture (25) of which is situated on a first surface (24) of the second surface (22) opposite to the second surface (17) of the first plate (12), is substantially equal to the output aperture (16) of the multiplier holes (13) and is smaller than the aperture (26) of the said auxiliary holes (23) which are defined on the second surface (27) of the

Abstract: A cathode ray tube comprising a channel plate electron multiplier structure disposed between a source of electrons and an output device such as a cathodeoluminescent screen. The electron multiplier comprises a stack of n apertured dynodes which are separated from each other and are arranged in cascade with the apertures in adjacent dynodes aligned to form channels. In order to improve the resolution of the electron multiplier while enabling the dynodes to be aceptably rigid the axial profile of the apertures in at least the second to the (n-1)th dynodes is such that it comprises a re-entrant portion within the thickness of the dynode with the axially spaced ends of the re-entrant portion being spaced from the respective opposite surfaces of the dynode by a convergent or cylindrical input portion and a divergent or cylindrical output portion.

Abstract: A penetron color display tube including a channel plate electron multiplier disposed between a low energy electron-beam-producing means and a luminescent screen. The screen is formed from repetitive groups of phosphor elements for luminescing in different colors. Each group includes a first phosphor element having a single layer of material for luminescing in a first color, such as blue, and a second phosphor element having two layers of material for luminescing in second and third colors, such as red and green. The channel plate electron multiplier includes a multiplicity of electron-multiplying channels for emitting individual electron beams when the low energy electron beam is directed into the channel's input.

Abstract: A middle-infrared image intensifier including an image-forming microchannel plate having an input face with a photoconductor material that is activated by middle-infrared radiation, means for flooding electrons to a region adjacent to the input face of the photoconductor, an electron sensitive light emitting screen positioned to receive electrons from the output face of the microchannel plate, and means for activating the microchannel plate to multiply electrons in channels of the microchannel plate having middle-infrared radiation incident thereon.

Abstract: The photomultiplier tube comprises an evacuated envelope having therein a photocathode, an anode, a plurality of spaced apart dynodes for propagating and concatenating electron emission from the photocathode to the anode and a pair of substantially parallel support spacers of insulating material to support the dynodes and the anode. A chrome oxide layer is disposed on the support spacers adjacent to the dynodes and the anode. The chrome oxide layer has a resistance of at least about 10.sup.12 ohms per square to about 10.sup.15 ohms per square. A Nichrome coating overlies an inter-electrode region extending along the concatenating path of the electron emission from the dynodes to the anode. The Nichrome coating has a resistance of greater than 10.sup.6 ohms per square but less than the resistance of the chrome oxide layer.

Abstract: A flat panel display for video and/or information display including a geometric array of individually energizable, low energy electron emitters in combination with an array of continuous channel electron multipliers for amplifying and directing the electron outputs of the emitters onto a phosphor screen to emit visible light.

Abstract: An electron multiplier structure comprising an electron multiplier section (11) with one or more microchannel plates and a dynode stage having secondary electron emission. This structure makes it possible to obtain an amplification which is higher than the amplification obtainable with only the electron multiplier section while maintaining the instantaneously obtained characteristics and special resolving power associated therewith.

Abstract: A deflection color selection system for a single beam channel plate display tube includes, within an envelope 10, a laminated dynode channel plate electron multiplier (16) having channels whose exit apertures are aligned in columns. An apertured extractor electrode (36) is mounted on and electrically insulated from an output face of the electron multiplier (16), the apertures (42) in the extractor electrode (36) being aligned with respective channels. A luminescent screen (14) spaced from the extractor electrode (36) includes patterns of phosphor elements (R, G, B) adapted to luminesce in different colors.

Abstract: The contrast ratio of an image intensifier of the photocathode-amplifier-phosphor type is increased by using a fiber optic plate of which the thickness is reduced to such extent that the plate may not be able to function as a vacuum seal or an electrical insulator when a typical voltage for the operation of the intensifier is applied to the phosphor layer. This relatively thin fiber optic plate is placed entirely inside a vacuum, protected from the atmospheric pressure by a thick output window plate which is optically transparent.

Abstract: In a laminated channel plate electron multiplier, an apertured metal sheet (32) is disposed at a small distance (30 .mu.m) from the outer surface of the input dynode and is used to provide a small negative field for turning back stray secondary electrons which have sufficient energy to follow trajectories across the input side of the input dynode. More particularly, the areas between the apertures of the input dynode (22) are masked by a material (34) having a secondary electron emission coefficient of less than 2, which material (34) is provided on the outer surface of the apertured metal sheet (32), the metal sheet (32) being spaced from the input dynode (22) by an insulating material (36). A potential of the order of -10 V relative to the input dynode is applied to the apertured metal sheet (32).

Abstract: The image contrast in an image display tube having a channel plate electron multiplier (2) is improved by preventing secondary electrons emitted from the face of an input dynode (26) from straying to channels located at a relatively large distance from their origin. This is done by disposing a grid (24) at a short distance from the input dynode (26). If the grid (24) is held at a positive voltage relative to the input dynode (26), stray secondary electrons will be attracted toward the grid (24). Alternatively, if the grid (24) is held at a negative voltage relative to that of the input dynode (26), the secondary electrons will be induced to enter channels close to their origin.

Abstract: In order to limit the increased quantity of ions produced within the tube as a result of the presence of a microchannel element within the tube, getters are placed on the probable path followed by the ions under the action of potentials applied to the electrodes. The electrodes to which the getters adhere are designed in two parts or constituent elements in order to permit the supply of getters if necessary. The electrode elements are bent-back in order to serve as shields in the case of vaporizable getters.

Abstract: A channel plate electron multiplier of the discrete dynode type formed from conductive sheets which are stacked in closely spaced relation. Each sheet is perforated with apertures which are aligned to form electron multiplying channels. The apertures in each sheet have input and output and cross sections which are approximately the same size and a concave shaped inner surface profile which causes a majority of electrons to strike the inner surface close to the output end, whereby the gain of the multiplier is increased.