Abstract: This invention relates to a photomultiplier for detecting the incident position of a plane of incidence, where a weak light beam is reached and to a photomultiplier having a structure for minimizing crosstalk near the incident position of the weak light beam to improve the precision of the position resolving power. Particularly, the anode of this photomultiplier, which extracts the incident position of the incident weak light as an electrical signal, is constituted by a first anode component for detecting the incident position of the incident plane in the X direction and a second anode component for detecting the incident position of the incident plane in the Y direction. The first and second anode components have flat surfaces. These flat surfaces cause the first and second anode components to capture secondary electrons emitted from a dynode in correspondence with the incident position of the weak light beam, at a position closer to the emission position.

Abstract: This invention relates to an improvement of a reflection mode alkali photocathode which relies on controlling a deposition weight of antimony. The reflection mode alkali photocathode according to this invention includes a thin layer of antimony directly deposited on a base substrate and activated by alkali metals. The thin film of antimony is deposited in a thickness of below 100 .mu.g/cm.sup.2. This reflection mode photocathode is suitably usable in photomultipliers. As the base substrate, nickel, aluminium and stainless, etc. are used. As the alkali metals, cesium, potassium, sodium and rubidium are usable.

Abstract: This invention relates to an improvement of a reflection mode alkali photocathode which relies on controlling a deposition weight of antimony. The reflection mode alkali photocathode according to this invention includes a thin layer of antimony directly deposited on a base substrate and activated by alkali metals. The thin film of antimony is deposited in a thickness of below 100 .mu.g/cm.sup.2. This reflection mode photocathode is suitably usable in photomultipliers. As the base substrate, nickel, aluminium and stainless, etc. are used. As the alkali metals, cesium, potassium, sodium and rubidium are usable.

Abstract: Support electrodes are provided for individually supporting a plurality of dynodes arranged inside of a vessel of an electron tube, such as photomultiplier tube. A black spacer formed from a ceramic material is disposed between the support electrodes. The black spacers are formed with elemental composition having content of MnO suppressed to 3 wt % or less. Current leaks, which are the cause of dark current, and abnormal generations of light during photomultiplication can be reduced, thereby improving the signal-to-noise ratio of the electron tube.

Abstract: A photomultiplier includes a photoelectric surface for photoelectrically converting incident light and emitting electrons, and a plurality of stages of dynodes for multiplying the electrons. The photomultiplier includes a first dynode array including box-and-grid dynodes arranged in a vessel and a second dynode array including in-line dynodes arranged in the vessel. A dynode having a curved secondary electron emitting layer opposes both a secondary electron emitting layer of a last stage dynode of the first dynode array and a secondary electron emitting layer of a first-stage dynode of the second dynode array.

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: An electron tube, such as, a photomultiplier, includes an aluminum seal ring 4 disposed between a Kovar cylinder 1, and a quartz faceplate 5 having a photocathode 6. The electron tube further includes a borosilicate stem plate 2, an anode 8, and a dynode 7. The aluminum seal ring 4 provides for increased air tightness, reliability, quantum efficiency, and gain.

Abstract: A photomultiplier includes a photocathode and an electron multiplier. A typical structure of the electron multiplier is obtained such that a dynode unit constituted by stacking a plurality of dynode plates in the incident direction of photoelectrons, an anode plate, and an inverting dynode plate are stacked. The anode plate has electron through holes at a predetermined portion to cause secondary electrons emitted from the dynode unit to pass therethrough. Each electron through hole has a diameter on the inverting dynode plate side larger than that on the dynode unit side, thereby increasing the capture area of the secondary electrons orbit-inverted by the inverting dynode plate.

Abstract: A micromachined electron multiplier is disclosed wherein a substrate has at least one trench formed therein and an aperture cover is disposed on the substrate with at least one inlet aperture aligned with one end of the channel. Either the substrate or the apertured cover may have an outlet aperture formed therein. A variety of channel shapes, and arrays are disclosed as well as a solid state photomultiplier tube formed with an integrated radiation window and anode structure.

Abstract: There is provided a photomultiplier in which a transmittance of an incident light and a photosensitivity is high and a hysteresis characteristic is excellent. Therefore, in the present invention, a photocathode 16, dynodes 17a to 17c and an anode 18 are supported between insulating material substrates 12a and 12b provided in a glass bulb 11. A transparent conductive film 19 is formed on an inside wall surface of a light entrance portion 15. The transparent conductive film 19 electrically contacts with a pad 20 which is led through a terminal 14 to the outside. The same potential as the photocathode 12 is applied through the pad 20 to the transparent conductive film 19. The incident light directly impinges on the photocathode 16 through the glass bulb 11 and the transparent conductive film 19 at a place corresponding to the light entrance portion 15. As a result, the incident light reaches the photocathode 12 with not being interfered at all, and the transmittance of the incident light is improved.

Abstract: A photomultiplier has a focusing electrode plate for supporting focusing electrodes, provided between a photocathode and a dynode unit. Since the focusing electrode plate has holding springs which are integrally formed with the focusing electrode plate, resistance-welding becomes unnecessary to prevent field discharge. A concave portion is formed in a main surface of the focusing electrode plate to arrange an insulating member sandwiched between the focusing electrode plate and the photoelectron incidence side of the dynode unit and partially in contact with the concave portion. With this structure, discharge between the focusing electrode plate and the dynode unit can be prevented.

Abstract: A two-dimensional radiation detecting method and apparatus for converting incident radiation in a two-dimensional distribution into electric signals. The apparatus includes a target structure and an electron beam scan mechanism. The target structure has a fluorescent element, transparent electrodes in stripes and a photoconductive film laminated in the stated order on a substrate. The electron beam scan mechanism has a plurality of linear cathodes, backing electrodes for taking electron beams from a selected linear cathode, a vertically converging electrode, vertically deflecting electrodes, accelerating electrodes and a decelerating electrode. The electron beam scan mechanism simultaneously projects the electron beams distributed horizontally to one horizontal line on the photoconductive film, and then shifts the electron beams vertically, to read a two-dimensional distribution of potentials on the photoconductive film.

Abstract: A photomultiplier tube which obtains a large decrease in manufacture time, prevents generation of gas within the envelope, prevents deterioration of electron multiplier assembly (dynodes), and greatly reduces noise. The envelope includes an all-metal cylindrical sidewall, at one end of which is an annular, flange-shaped, metal sealing area. The stem of the photomultiplier tube has another annular flange-shaped, metal sealing area. These two sealing areas are welded together. Also a metal exhaust tube is connected to the stem by resistance welding. The metal exhaust tube is severed using pinch-off seal at the final stage of the photomultiplier tube production.

Abstract: A photomultiplier which can be easily made compact has a dynode unit constituted by stacking a plurality of stages of dynode plates in an electron incident direction in a vacuum container constituted by a housing and a base member integrally formed with the housing. Each dynode plate has an engaging member engaged with a connecting pin for applying a voltage at a side surface thereof. Through holes for guiding the connecting pins from the outside of the container are formed in the base member. Each engaging member is arranged not to overlap the remaining engaging members in the stacking direction of the dynode plates. The arrangement position of each engaging member and the arrangement position of the through hole for guiding the corresponding connecting pin to be connected are matched with each other.

Abstract: A photomultiplier uses an avalanche photodiode as a position-sensitive anode. The envelope of the photomultiplier has a flat input end. Electrically conductive regions mounted to the input end are configured to produce at the input end a potential distribution characteristic of a photomultiplier with a spherical-type input end as measured in a transverse plane immediately adjacent the spherical-type input end. A photocathode is located inside the photomultiplier and is electrically connected to the electrically conductivew regions. Advantageously, the envelope has flat sides and a square cross-section; in this instance, conductors are run along the sides to produce within the envelope a potential distribution characteristic of a photomultiplier which is cylindrical in cross-section, as measured at flat surfaces having the same shape as the envelope.

Abstract: A photomultiplier which can be easily made compact has a dynode unit having a plurality of dynode plates stacked in an electron incident direction in a vacuum container fabricated by a housing and a base member integrally formed with the housing. Each dynode plate is constituted by welding at least two plates overlapping each other. The welding positions do not overlap each other in the stacking direction of the dynode plates. With this structure, field discharge at the welding portions between the dynode plates can be prevented to reduce noise.

Abstract: A focused electron/bombarded hybrid photomultiplier tube comprising a photocathode, focusing electrodes, and a collection anode disposed in a detector body. The collector anode includes a diode for receiving the focused output electron beam from the photocathode. The current gain between the photocathode output current and the detector output signal from the diode is over 1000 at a tube operating voltage of 7 kV. The noise factor has been determined to be 1.1. A hybrid photomultiplier tube includes a photocathode, a photodiode for collecting and multiplying electrons emitted by the photocathode and providing an output signal and electrodes for focusing the electrons on the photodiode. A vacuum envelope encloses a vacuum region between photocathode and the detector. A conductor disposed on or adjacent to a sidewall of the vacuum envelope reduces the effect of electrical charges on the inside wall of the vacuum envelope on the trajectories of the electrons.

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 focused electron/bombarded (FEB) ion detector comprising an MCP, focusing means, and a collection anode disposed in a detector body. The collector anode includes a diode for receiving the focused output electron beam from the MCP. The gain between the input ion current to the MCP and the detector output signal from the diode is on the order of 1-100 million, depending on the device configuration and applied biasing voltages. A hybrid photomultiplier tube includes a photocathode, a photodiode for collecting and multiplying electrons emitted by the photocathode and providing an output signal and electrodes for focusing the electrons on the photodiode. A vacuum envelope encloses a vacuum region between photocathode and the detector. A conductor disposed on or adjacent to a sidewall of the vacuum envelope reduces the effect of electrical charges on the inside wall of the vacuum envelope on the trajectories of the electrons.

Abstract: There is disclosed a process for forming a photocathode having high quantum yield which comprises the first step of making a number of fine concavities and convexities in a surface of a substrate finished substantially in a mirror; the second step of blunting the fine concavities and convexities; and the third step of coating a photoelectron emissive material on the surface of the substrate.

Abstract: A method is described for manufacturing a correction mask for an image intensifier tube of the proximity-focus type having an oblong cathode and anode. Such image intensifiers tend to have a non-uniform light output at the anode in response to a uniform input image at the cathode. A measurement is made of the light output distribution along at least one line at the anode under uniform illumination of the cathode, which measurement is used to manufacture a transparency for attachment on the output window of the image intensifier tube. The transparency is provided with a light absorbing line, which line absorbs more light at those positions along the length of the output window where the light output was higher. The absorbence of the light absorbing line is made proportional to the difference between the actual light output and required value light output, whereby the light output of the image intensifier tube is equalized to a required level.

Abstract: A high performance reflection type photocathode for use in a photomultiplier tube is formed by sequentially depositing three layers on a substrate made of nickel. The first layer is made of either one of chromium, manganese and magnesium as a major component and is deposited over the substrate. The second layer is made of aluminum as a major component and is deposited over the first layer. The third layer is made of antimony and at least one kind of alkaline metals and is deposited over the second layer.

Abstract: Method and apparatus for measuring the time of short events, such as characteristics of a source of short radiation pulses or lifetime of excited states of a sample. The method and apparatus is based on a multi-step photoemission process from an active element target exhibiting superlinear photoemission. A short prompt radiation pulse is used to raise electrons to an excited state, and a following overlapping short probe pulse is used to raise the excited electrons to the vacuum level where they leave the sample, changing its charge state. The number of escaped electrons is measured as a function of the time delay between the prompt and probe pulses to provide the sought after information. Preferably, the charged target is suspended or supported in an electric field, and the voltage needed to restore the charge-changed target to its original position is used.

Abstract: An image intensifier tube is provided with a channel plate. The channel plate's channels are open both at the cathode side and at the anode side. A high frequency alternating electric field is generated in the space between the cathode and the channel plate. Thereby during a first period of the cycles of the alternating electric field the photoelectrons emitted by the photocathode traverse the space between the photocathode and the channel plate. During a second period of the cycles of the alternating electric field, in which second periods the polarity of the electric field is reversed with respect to the polarity during the first period, any ions that may have emerged from the channels into the space between the photocathode and the channel plate are drawn back to the channel plate.

Abstract: An image dissecting intensifier tube for use in an x-ray examination system is taught. X-ray photons pass through a subject are received by the image dissecting intensifier tube, which converts the photons to electrons. By use of electrostatic plates, the electrons are accelerated, deflected horizontally and vertically, and focused as they pass through the tube. The electrons emit from the tube by feeding the electron image line-by-line through a small aperture formed in the anode of the tube. The video signal that pass through the aperture are received by a multiplier tube built onto the image dissecting intensifier tube which amplifies the signal. The signal passes to a video control unit, which takes the amplified signal and mixes the signal with horizontal and vertical sweep signals, producing a composite video signal. The composite video signal is then displayed on a monitor for viewing. The image obtained is brighter and clearer than that achieved by traditional x-ray systems.

Abstract: A night vision scope which includes an improved voltage supply. A battery generates a voltage which is proportionally increased by a voltage step-up circuit to provide a voltage to an image intensifier and an infrared light source of the night vision scope. The voltage supply includes circuitry for limiting the voltage output of the voltage supply circuit if a battery is used which generates a voltage greater than that required by the elements of the night vision scope.

Abstract: 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.

Abstract: The present invention refers to a digital anode that permits capturing electrons and digitalizing their location on a given surface, so that it can be stored in a memory to be later processed and either interpreted, printed, filtered or transferred.

Abstract: A multiple section photomultiplier tube constructed as a matrix of several independent tubes in one envelope. The photocathode to dynode spacings are isolated by a separator configuration built with walls which interlock in cooperating slots, and each photocathode operates with its own independent dynode cage. One dynode in each cage is maintained electrically independent, and its connection is brought out of the envelope independently. This permits independent adjustment of the gain for each of the tube's multiple sections, so they can be adjusted to the same response for a standard radiation signal. The entire tube can then be used to monitor a large area for radiation, and will yield the same response over its entire cathode area.

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: 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 comprising a photocathode, a plurality of mesh dynodes arranged parallel to the photocathode, an anode that is disposed in a face-to-face relationship with the photocathode in such a manner that the mesh dynodes are interposed between the anode and the photocathode, the anode being divided into segments larger than the openings of each dynode, and at least one layer of focusing electrode for focusing an electron beam by the lens action which is disposed between the photocathode and the anode.

Abstract: A femtosecond sampling oscilloscope includes a femtosecond laser for generating a pulse of light in the femtosecond range and a beam splitter for splitting the pulse of light into pulses traveling along first and second beam paths. A photoconductive switch disposed along the first beam path is used to produce an electrical stimulus output at a first output port, an electrical pulse output at a second output port and an optical output at a third output port. A photomultiplier tube having a strip line photocathode receives the pulse of light traveling along the first beam path. An input port is coupled to the photocathode. In use, the output signal at one of the output ports is connected to a test device producing a test voltage signal which is applied to the input port. When the test voltage signal and the light pulse traveling along the second path intersect on the photocathode in space and time, an electrical signal output is produced at the photomultiplier tube.

Abstract: A photo electric conversion tube in which a translucent photocathode surface is provided inside of an incident light window. The incident light window is made of glass plate and an optical fiber plate bonded to at least part of the glass plate or just the optical fiber plate on the photocathode surface. The optical fiber plate contains fibers which are inclined at an angle to the photocathode surface.

Abstract: A long photomultiplier comprises a cylindrical main body having a light receiving face which extends in the longitudinal direction of the main body, a photocathode provided inside of the main body so that the photocathode extends along the light receiving face and emanates photoelectrons when exposed to light, and dynodes provided inside of the main body for multiplying the emanated photoelectrons. A reflection plate is provided facing and extending along the light receiving face, and the photocathode is positioned between the light receiving face and the reflection plate. The reflection plate is positioned for reflecting light, which has passed through the photocathode, toward the photocathode.

Abstract: A photomultiplier with plural photocathodes comprising a rectangular end face plate, plural photocathodes arranged on the end face plates at predetermined intervals in the longitudinal direction of the end face plate, plural focusing electrodes assigned to the photocathodes respectively, plural dynodes provided in common for all of the photocathodes, and plural anode electrodes assigned to the photocathodes respectively, each of the dynodes having plural electron emitting parts for emitting secondary electrons and insulating parts for preventing the secondary electrons emitted from any one of the electron emitting parts from straying into the other electron emitting parts.

Abstract: A method of manufacturing a photomultiplier tube (10) comprising a tube body (20), a photocathode (30) and an electron multiplier element (40) destined to be placed at a small distance from the photocathode (30). According to the invention the tube (10) is provided with sliding means (50) of the electron multiplier (40) parallel to the axis (22) of the tube body (20), means (50) provided with abutments (53) situated in the proximity of the said window (31).

Abstract: An image read-out apparatus includes a main scanning device for scanning a sheet carrying an image recorded thereon with a light beam in a main scanning direction and obtaining light carrying the image information from the sheet, a sub-scanning device for moving the sheet with respect to the light beam in a sub-scanning direction approximately normal to the main scanning direction, and a light detector for detecting the light obtained from the sheet. The light detector comprises a long photomultipler having a light receiving face extending along the main scanning line and positioned close to the sheet.

Abstract: A focusing electrode structure for a photomultiplier tube which optimizes the tube operation. One or more focusing electrodes located between the photocathode and the first dynode are configured in the shape of substantial sections of a spheroid dome with the smaller opening nearer to the photocathode. In the preferred embodiment three focusing electrodes are used with their sizes increasing and their voltages decreasing as they approach the photocathode.

Abstract: A photomultiplier tube which may be used in time resolving a luminiscence profile emitted from a sample with picosecond resolution using short (picosecond) electrical pulses as a probe and in time resolving an electrical pulse profile produced by fast electronic or optoelectronic devices with femtosecond resolution, using short (femtosecond) laser pulses as the probe is disclosed.

Abstract: A photocathode current sensing circuit (58) is provided to adjust the electron accelerating voltage to a cone (32) and a phosphor screen (34) on an image intensifier tube (26). The voltage is adjusted by an anode power supply (60) which is responsive to the photocathode current sensing circuit (58). As light strikes the photocathode (28), a current (56) is generated. The current (56) is directly proportional to the intensity of light striking the photocathode (28). As the light and the current (56) decrease, the sensing circuit (58) controls the power supply (60) to provide a higher voltage to the cone (32) and the screen (34). By increasing the voltage to the cone (32) and the screen (34) the electrons are provided with more acceleration and, therefore, are intensified for viewing on the screen (34). An increase in light operates oppositely and decreases the intensity on the screen (34).

Abstract: A photomultiplier includes a solid disk dynode and a pair of annular guiding electrodes disposed about the disk dynode transversely along the central axis of the photomultiplier tube on opposite sides of the dynode. The secondary and subsequent dynodes may be of conventional (e.g. venetian blind) construction or of solid disk construction. The solid disk dynode and guiding structure exhibits improved photoelectron pulse-height resolution and a better signal-to-noise ratio than a conventional venetian blind type dynode. In addition, the solid dynode structure is less susceptible to physical shock than conventional photomultiplier dynode designs.

Abstract: An electron tube device for measuring light pulses generated at a high repetition rate which includes an electron tube, power supply device and deflection voltage generator. The electron tube has a photocathode, focusing electrode, deflection electrodes, slit electrode, dynodes and a collector electrode positioned within an evacuated envelope. The power supply device supplies voltages to the dynodes and to the focusing and slit electrodes, and the deflection voltage generator supplies deflection voltages to the deflection electrodes which successively change in phase with respect to light pulses impinging on the photocathode so that different portions of the light pulses can be successively sampled.

Abstract: A photomultiplier used in liquid scintillation counting has an envelope, a base, an anode, a curved dynode structure and a photocathode. A specimen is inserted in a measuring area of the envelope for liquid scintillation counting. The photocathode has a concave surface, so that the specimen is encircled by the photocathode as completely as possible. The photocathode is positioned at a concave window of the envelope, so that a maximum number of photons directly impinge on the photocathode.

Abstract: An optical amplifier having, for example, a photocathode to convert light to electrons, an electron multiplier, and a photo-emitter or light emitting diode to convert electrons to light. The electron multiplier may be made of magnesium oxide, silicon dioxide or silicon dioxide having bubbles therein. Alternatively, the electron multiplier may be an avalanche diode or other diode.

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.

Abstract: The radiation detecting apparatus contains at least one photomultiplier tube for the detection of light. It has been found that the photomultiplier tube will emit erroneous output signals when exposed to a perturbing magnetic field. This is particularly true for photomultiplier tubes used in scintillation cameras and in emission computed tomography systems where the detector head containing photomultipliers changes position during operation. In order to reduce the magnetic field sensitivity, the radiation detection apparatus contains means for superimposing an artificial magnetic field on the perturbing magnetic field at the location of the photomultiplier tube. This artificial field may either be a compensating field or, preferably, an enhancing field which is larger than the perturbing field. The artificial field may be either generated by coils, such as Helmholtz coils, or by a permanent magnet. The coil(s) may be arranged inside or outside the camera head.

Abstract: An image intensifier tube and a method of making same is disclosed wherein veiling glare caused by the amplification of off axis light is reduced. Included is a colored, low reflective, light absorbing layer formed in the face plate of the tube adjacent any surface at which off axis light could otherwise be reflected to the photoemissive device associated with the face plate.

Abstract: A planar mesh structure that facilitates forming into a non-planar mesh structure comprises a peripheral support ring lying in a plane with a plurality of first members and a plurality of second members lying in the plane. The first members comprise substantially concentric, spaced-apart mesh rings of progressively decreasing diameter disposed within the peripheral support ring. The plurality of second members extend generally inwardly from the peripheral support ring and terminate at the innermost of the first members. The second members intersect the first members disposed between the peripheral support ring and the innermost first member to form, with the intersected first members, a plurality of apertures. In one embodiment, the second members are generally arcuately shaped and lie in a first plane with the support ring and the first members.