Abstract: Apparatus for the inspection of cargo containers for nuclear materials comprising one or more arrays of modules comprising grounded, closed conductive tubes filled with an ionizing gas mixture such as, but not limited to, Argon:CO2. A wire is suspended along each tube axis and electrically connected at both ends of the tube. A positive, dc high voltage is supplied to one end of the wire and an amplifier is attached to the other end through a capacitance to decouple the amplifier from the high voltage. X-rays, gamma rays or neutrons produced by nuclear material and passing through the tube ionize the gas. The electrons from the gas ionization process are accelerated toward the wire surface due to the wire's electrical potential. The acceleration of the electrons near the wire's surface is sufficient to ionize more gas and produce an amplification of electrons/ions that create a surge of current large enough to be detectable by the amplifier.

Abstract: X-ray imaging systems are provided. A representative x-ray imaging system includes a gas detector that is configured to retain a volume of gas. The gas detector incorporates a first detection circuit corresponding to a first region of the gas and a second detection circuit corresponding to a second region of the gas. The first detection circuit is adapted to provide a first signal indicative of an intensity of x-rays radiating into the first region of the gas and the second detection circuit is adapted to provide a second signal indicative of an intensity of x-rays radiating into the second region of the gas. Methods and other systems also are provided.

Abstract: A two-dimensional, pixellated, monolithic semiconductor radiation detector, in which each detector pixel is essentially a perpendicular mode detector. This is achieved by an arrangement of anode spots, one for each pixel located on the flux-exposed front surface of the detector substrate, surrounding by a cathode array preferably in the form of a network of lines, such that the field between the anodes and cathodes on this front surface has a major component in the direction parallel to the surface, and hence perpendicular to the incident photon flux. The conductivity of the substrate is high near this front surface, since this is where the highest level of absorption of photons takes place, and a significant photoconductive current is thus generated between cathodes and anodes. The conductivity is proportional to the incoming photon flux, and decays exponentially with depth into the detector.

Abstract: In detectors for imaging and other applications, delay line anodes are arrayed so as to allow detection of the location and/or timing of particle hits. The anodes are arrayed to provide an upper anode and one or more lower anodes, with particles incident on the upper anode passing in turn to the lower anodes. The anode arrays allow the use of identically manufactured anodes which are maintained in parallel spaced relation along the travel path of the particles of interest without dielectric material or other structure situated between the anodes. The spacing between the anodes is preferably adjustable so as to allow the installer and/or user to modify the performance characteristics of the array. The anodes may be made of pre-formed metal foil signal and ground layers laminated onto opposing sides of a dielectric sheet, or may be etched or otherwise formed from flex circuit material, so that the anodes and the overall array are light weight, compact, and flexible.

Abstract: The invention relates to a radiation detector for converting electromagnetic radiation (15) into electric charge carriers. The invention also relates to an X-ray examination apparatus provided with such a radiation detector, and to a method of manufacturing a radiation detector. In order to achieve a small building height of the radiation detector while nevertheless satisfying the same requirements as regards the resetting of the converter arrangement (16, 18) by means of an illumination device (6), it is proposed to provide a supporting layer (8) underneath a glass plate (2a) with a photosensor arrangement (2b), which supporting layer on the one hand provides uniform distribution of the light incident from below and on the other hand imparts the necessary stability to the radiation detector.

Abstract: The present invention relates to a microstrip gas chamber and microstrip plate capable of reading signals from readout electrodes provided at a rear surface of the substrate in a superior manner while having a simple and compact configuration. The microstrip plate comprises an electrically insulating substrate 1, cathodes 2 and anodes 3 arranged alternately at the surface of the substrate 1, read-out electrodes 4 arranged so as to intersect the cathodes 2 and anodes 3 at the rear surface of the substrate 1, wherein a plurality of unitary regions 20 are provided at the surface of the substrate 1 and each unitary region 20 is electrically floated from the cathode via a resistance region 5.

Abstract: An ionizing radiation detector comprising a plurality of conductive tubes arranged in parallel fashion containing a gas mixture under pressure, a conductive wire being tensed at the center of each tube and adapted to being polarized with respect thereto, and comprising first and second tight enclosures each having a wall provided with openings in which are tightly inserted the first and second ends of each tube, the ends of each tube being open.

Abstract: Two-dimensional detector of ionizing radiation and process for manufacturing this detector This detector comprises sheets (4) emitting particles by interaction with ionizing radiation, semiconducting layers (6) that alternate with the sheets and can be ionized by the particles, and groups of conducting tracks (22) in contact with the layers. Means (26) of creating an electric field are used to collect charge carriers generated in the layers due to interaction with particles, through the tracks. For example, the layer and the corresponding tracks are formed on each sheet and the sheets are then assembled together. For example, the invention is applicable to radiography and can achieve good X-ray detection efficiency and high spatial resolution at the same time.

Abstract: A method for detection of ionizing radiation comprises the steps of (i) directing ionizing radiation towards an object to be examined; (ii) preventing Compton scattered radiation, preferably at least 99% of the radiation Compton scattered in said object, from being detected; and (iii) detecting ionizing radiation spatially resolved as transmitted through said object to reveal a spatially resolved density of said object, wherein said ionizing radiation is provided within a spectral range such that more, preferably much more, photons of said ionizing radiation are Compton scattered than absorbed through the photoelectric effect in said object to thereby reduce the radiation dose to said object.

Abstract: A photoionization detector comprising multiple ionization cells for detecting the presence of chemical compounds in multiple fluid samples. The photoionization detector uses a single source of ultraviolet (UV) radiation to emit high energy photons into at least two ionization cells. Each ionization cell comprises at least one fluid inlet and at least one fluid outlet. Independent samples of fluid can be introduced into each cell and exposed to the UV radiation such that any molecules with an ionization energy lower that the energy of the photons are ionized. Each ionization cell also comprises a set of at least two electrodes arranged to generate an electric field such that ionized molecules are attracted to the electrode at lower voltage potential resulting in an electrical current.

Abstract: A radiation measurement device includes a radiation detector generating an analog signal containing pulse components, an A/D converter converting the analog signal into sampled data, an n-th power pulse discrimination unit calculating n-th power values of the sampled data to discriminate the pulse component, where n is two or more, and a pulse counter counting a number of the discriminated pulse components.

Abstract: The invention provides apparatus and methods which facilitate movement of an instrument relative to an item or location being monitored and/or the item or location relative to the instrument, whilst successfully excluding extraneous ions from the detection location. Thus, ions generated by emissions from the item or location can successfully be monitored during movement. The technique employs sealing to exclude such ions, for instance, through an electro-field which attracts and discharges the ions prior to their entering the detecting location and/or using a magnetic field configured to repel the ions away from the detecting location.

Abstract: A radiation detector comprises two electrode arrangements, each including a dielectric substrate and an electrically conducting layer formed on a first surface of respective dielectric substrate, wherein the electrodes are oriented such that the conducting layers are facing each other. A dielectric spacer is provided to hold the electrodes at a distance from each other to thereby define an inter-electrode space, which, during use, is filled with an ionizable gas. The electrodes are held at respective electric potentials to drift electrons released during ionization of the ionizable gas by external radiation towards one of the electrodes for detection.

Abstract: An apparatus for surface treating a semiconductor wafer includes a surface treatment chamber and a source of radiation. The semiconductor wafer disposed inside the chamber is illuminated with radiation sufficient to create a plurality of electron-hole pairs near the surface of the wafer and to desorb ions and molecules adsorbed on the surface of the wafer.

Abstract: A radiation detector arrangement for imaging of an object comprises multiple line detector units, each being arranged for one-dimensional imaging of the respective ray bundle. The detector units are arranged parallel in a two-dimensional array. The detector units are sited in rows and stacks, the rows being parallel with the detector unit and the stacks being orthogonal thereto, where the one-dimensional detector units in each row are together capable of detecting the object in one dimension. A device is provided for moving the detector units relative the object parallel with the stacks at least a distance corresponding to the distance between two adjacent detector units in the stacks.

Abstract: A system is presented for remotely measuring a concentration of a target material (e.g., radioactive gas, suspended aerosols or non-radioactive gaseous chemistries). The system includes a data processing system and a monitoring device. The device includes a detector having a chamber, collector in the chamber and a sensor. The target material enters the chamber. The collector collects ions generated by decay of the material. In one embodiment, the sensor measures changes in an electrostatic potential of the collector in response to the ions. In another embodiment, the sensor includes a scintillation counter that measures alpha or beta particles and provides an energy spectrum. In another embodiment, the sensor includes a material whose optical properties vary according to fields formed within the sensor. The device includes a transmitter for transmitting the potential, the spectrum or the field strength to the processing system for determining the concentration of the target material.

Abstract: The present invention concerns an ionization chamber cylindrical in shape comprising an anode (35) formed by a central rod in current-carrying material and a cathode (38) in current-carrying material around the said anode, both connected to two elements of a mechanical base of the said chamber in which two cylindrical end shields (36, 37) in non-magnetic and insulating material are centred on the anode (35) and arranged at right angles to this at both ends, the cathode (38) being made up of a spooled wire on the outer rim of these two end shields (36, 37).

Abstract: A photo-ionization detector (PID) including two detection units controls gas flows through the ionization chambers of the detection units for real-time self-cleaning and measurement. Operation of the PID can include flowing gas through the ionization chamber of one detection unit to measure the volatile gas concentration while stopping gas flow through the ionization chamber of the other detection unit. A UV lamp converts oxygen contained in the closed ionization chamber to ozone, which removes contamination in the closed ionization chamber, Continuous gas flows can alternate between one ionization chamber to the other. Alternatively, a PID with only one gas detection unit intermittently interrupts the flow of the ambient gas in the ionization chamber.

Abstract: An ionization chamber is provided for the detection of nuclear radiation. The chamber is a vessel which acts as a cathode wherein at least one anode is disposed within the chamber and off-set from a center axis of the chamber. The chamber can be made from variety of shapes but is cylindrical in the preferred embodiment. The device contains two anodes in the preferred embodiment which are both off-set from the center axis. One anode collects the free floating electrons which are produced in response to particle ionization and therefore has a collected charge applied thereto. The second anode has the charge induced by immobile ions. The induced charge is subtracted from the collected charge thereby providing an improved resolution for the ionization chamber which translates into a more accurate result. In the preferred embodiment, a pressurized noble gas, such as xenon, is used.

Abstract: A process for modification of a surface structure by exposing the surface to a flow of neutral atomic or molecular gaseous medium excited to metastable level which is produced in a process of blowing a working gaseous medium through a discharge gap filled with plasma generated from this working gaseous medium.

Abstract: A microstrip gas chamber (MSGC) comprises a gas volume, an electrically insulating substrate having a surface exposed to the gas volume. A set of alternating cathode strips and anode strips are provided on the surface of substrate, a high voltage source for establishing a potential difference between the anode and cathode strips is provide to produce an electric field sufficient for avalanche multiplication in said gas medium in a region near the anode strips. Grid electrodes are provided on the surface at each gap between the cathode strip and anode strip. The multi-grid type MSGC can offer very narrow gap between neighboring electrodes that might reduce a surface charge effect considerably. The multi-grid type MSGC may be applied to the field where both high gain and the stable operation are required.

Abstract: A wireless lighting system for providing convenient illumination where needed with centralized control. The wireless lighting system includes a main transmitter assembly providing a centralized control capability; including a housing defining an interior space and a transmitter member positioned substantially within the housing for generating and transmitting control signals, and a plurality of lamp assemblies each having a base portion and a lamp member. Each lamp member selectively provides illumination. Each one of the base portions has a base housing defining an interior space and an energy storage member positioned within said housing for selectively providing electrical current to an associated lamp member. Additionally, each one of said base portions includes a receiver portion positioned within the housing for receiving control signals generated and transmitted by the transmitter member.

Abstract: The apparatus and method provide a technique for significantly reducing capacitance effects in detector electrodes arising due to movement of the instrument relative to the item/location being monitored in ion detection based techniques. The capacitance variations are rendered less significant by placing an electrically conducting element between the detector electrodes and the monitored location/item. Improved sensitivity and reduced noise signals arise as a result. The technique also provides apparatus and method suitable for monitoring elongate items which are unsuited to complete enclosure in one go within a chamber. The items are monitored part by part as the pass through the instrument, so increasing the range of items or locations which can be successfully monitored.

Abstract: The present invention describes an apparatus for detection of ionizing radiation, wherein the incident radiation ionizes a substance, and the electrons released as a result thereof are accelerated in a dual parallel plate electrode arrangement. These electrons will interact with a scintillating substance to emit light, which is detected by a position sensitive light detector. Since the light is emitted isotropically in such scintillator measures are taken to achieve a good spatial resolution. Thus, the scintillating substance is either arranged in an array of separately located scintillating elements, wherein each scintillating element is separated from the other ones by means of a light impermeable wall, or has an extension in the direction of the accelerated electrons shorter than the absorption length of the light photons emitted in the scintillating substance.

Abstract: A detector for detection of ionizing radiation comprises a cathode; an anode; an ionizable gas arranged between these electrodes; a radiation entrance arranged such that ionizing radiation can enter and ionize the ionizable gas; and a readout arrangement. A voltage across the electrodes causes electrons created during ionization of the gas to drift towards the anode, where the readout arrangement detects them. To reduce the risk of occurrence of sparks, and/or to reduce the energy in occurring sparks, one of the cathode and anode has at least the surface layer facing the other electrode made of a material having a resistivity of at least 5×10−8 &OHgr;m.

Abstract: A detector for detection of ionizing radiation comprises a first cathode and a first anode between which a first voltage is applicable; an ionizable gas arranged at least partly between the first cathode and the first anode; a radiation entrance arranged such that ionizing radiation can enter and ionize the ionizable gas; and a read-out arrangement. The detector further comprises a second cathode and a second anode between which a second voltage is applicable; and a solid state ionizable material arranged between the second cathode and the second anode such that part of the radiation entered into the ionizable gas can propagate through the gas, enter the solid state material and ionize it; wherein the read-out arrangement is arranged for detection of the electrons and/or holes drifted towards the second anode and/or cathode, respectively, separately of detection of the electrons drifted towards the first anode.

Abstract: An apparatus for planar beam radiography comprises an ionizing radiation source and an ionizing radiation detector; the ionizing radiation source being line-like and extending substantially in a first direction; and the ionizing radiation comprising an elongated radiation slit entrance extending substantially in a second direction and being arranged for one-dimensional detection of radiation from the radiation source entering the detector through the radiation slit entrance. According to the present invention the radiation source and the radiation dectector are oriented such that the first and second directions are essentially perpendicular. Hereby,a facilitated alignment of the detector with respect to source is achieved.

Abstract: A method for detecting ionizing radiation, a detector (64) for detection of ionizing radiation, and an apparatus for use in planar beam radiography, including the detector. The detector includes: a chamber filled with an ionizable gas; first and second electrode arrangements (2, 1, 18, 19) provided in the chamber with a space between them, the space including a conversion volume (13); an electron avalanche amplification unit (17) arranged in the chamber; and, at least one arrangement of read-out elements (15) for detection of electron avalanches. Radiation enters the conversion volume between the first and second electrode arrangements via a radiation entrance. The distance between the first and second electrode arrangements is selected to achieve discrimination of fluorescent photons and/or long-range electrons, in order to achieve improved position resolution.

Abstract: The invention provides apparatus and methods which facilitate movement of an instrument relative to an item or location being monitored and/or the item or location relative to the instrument, whilst successfully excluding extraneous ions from the detection location. Thus, ions generated by emissions from the item or location can successfully be monitored during movement. The technique employs sealing to exclude such ions, for instance, through an electro-field which attracts and discharges the ions prior to their entering the detecting location and/or using a magnetic field configured to repel the ions away from the detecting location.

Abstract: A design and readout of a xenon detection medium based device, which provides improved spectroscopic performance compared to currently commercially available devices. To achieve energy resolution improvement, a method to accurately measure radial spatial position for interacting events within a HPXe cylindrical detector is described using the plan as shown in FIG. 4. This is accomplished by utilization of light generated both at the gamma interaction site and at the collection point near the anode wire of the cylindrical detector. These light flashes are detected by a VUV photon detector. Light transmission is facilitated by incorporating a vacuum ultraviolet (VUV) light transparent window at least one end of the cylindrical ionization detector. With the known electron drift velocity in HPXe, the time between these two photopulses is sufficient to accurately determine the radial coordinate. Consequently, correction by electronic means for the electrostatic pulse dispersion using the expression graphed in FIG.

Abstract: The apparatus and method provide a technique for significantly reducing capacitance effects in detector electrodes arising due to movement of the instrument relative to the item/location being monitored in ion detection based techniques. The capacitance variations are rendered less significant by placing an electrically conducting element between the detector electrodes and the monitored location/item. Improved sensitivity and reduced noise signals arise as a result. The technique also provides apparatus and method suitable for monitoring elongate items which are unsuited to complete enclosure in one go within a chamber. The items are monitored part by part as the pass through the instrument, so increasing the range of items or locations which can be successfully monitored.

Abstract: A detector for detection of ionizing radiation comprises a chamber (13) filled with an ionizable gas, and including a first (17, 19) and a second (21) electrode arrangement between which a first voltage (U1, U2) is applicable, a radiation entrance (33) arranged such that radiation (1) can enter the chamber between and substantially in parallel with the first and second electrode arrangements, for ionization of the ionizable gas, an electron avalanche amplification arrangement (15) including an avalanche cathode arrangement (25) and an avalanche anode arrangement (27), between which a second voltage (Ua) is applicable, and a read-out arrangement (29), wherein the first voltage is applicable for drifting electrons created during ionization towards the electron avalanche amplification arrangement, the second voltage is applicable for avalanche amplification of said electrons, and the read-out arrangement is arranged for detection of the electron avalanches and/or correspondingly produced ions.

Abstract: A method and apparatus for monitoring alpha contamination are provided in which ions generated in the air surrounding the item, by the passage of alpha particles, are moved to a distant detector location. The parts of the item from which ions are withdrawn can be controlled by restricting the air flow over different portions of the apparatus. In this way, detection of internal and external surfaces separately, for instance, can be provided. The apparatus and method are particularly suited for use in undertaking alpha contamination measurements during the commissioning operations.

Abstract: In order to obtain suitable absorption of the radiation to be detected in the detector gas of a radiation detector, in particular an X-ray detector, the detector is constructed in such a way that the radiation enters the detector parallel to the counting wire, thus offering an absorption path having any desired length. According to the invention, a number of avalanche chambers 50 is arranged adjacent the absorption chamber 46, said avalanche chambers having a comparatively small cross-section. The avalanche chambers are provided with grids 54 in such a way that charge multiplication by the grid voltage can occur only in the avalanche chamber. Due to the comparatively small cross-section of the avalanche chambers, broadening of the current impulses to be detected is prevented. Moreover, the comparatively long absorption chamber offers good radiation absorption and the presence of several avalanche chambers enables a favourable detection rate.

Abstract: A flat panel x-ray imager includes a gain layer (charge multiplication layer) that facilitates imaging at low x-ray exposure levels. The gain layer can be a gas chamber or a solid state material operating in an avalanche mode.

Abstract: A Geiger-Mueller triode directional sensor is provided to detect the direction of incident ionizing gamma radiation, comprising a housing divided into two subchambers, or GM counters, separated by a partition composed of a high Z layer of tungsten, the tungsten partition having an aperture for gas to freely communicate between the subchambers and maintain an identical gas mixture in both subchambers, radiation windows, external layers of a second material in the sidewall and a sensor. Incident gamma rays generate electrons within the tungsten partition, housing and the sidewall based on the photoelectric, Compton and pair effects. The electrons penetrate the radiation windows and are accelerated by an applied electric field in the housing, causing the electrons to ionize the gas within the housing and produce electrical discharges.

Abstract: A sensor for detecting the flame occurring during a flashback condition in the fuel nozzle of a lean premix combustion system is presented. The sensor comprises an electrically isolated flashback detection electrode and a guard electrode, both of which generate electrical fields extending to the walls of the combustion chamber and to the walls of the fuel nozzle. The sensor is positioned on the fuel nozzle center body at a location proximate the entrance to the combustion chamber of the gas turbine combustion system. The sensor provides 360° detection of a flashback inside the fuel nozzle, by detecting the current conducted by the flame within a time frame that will prevent damage to the gas turbine combustion system caused by the flashback condition.

Abstract: A detector unit for detecting photons in the energy range 1 keV to 100 MeV, includes at least two converter layers adapted to interact with incident X-ray photons and to cause electrons to be emitted therefrom, at least one amplifier adapted to interact with the electrons emitted from the converters and adapted to produce a multiplicity of secondary electrons and photons representing a signal proportional to the incident fluence of X-ray photons, a connector connecting the detector to an electric field generator providing an electric drift field for secondary electrons in the detector, and a sensor device arranged to receive the signal and provide an input to electronic signal processor.

Abstract: A detector (64) for detection of ionizing radiation, an apparatus for use in planar beam radiography, comprising such a detector, and a method for detecting ionizing radiation. The detector comprises: a chamber filled with an ionizable gas; first and second electrode arrangements (2, 1, 18, 19) provided in said chamber with a space between them, said space including a conversion volume (13); means for electron avalanche amplification (17) arranged in said chamber; and, at least one arrangement of read-out elements (15) for detection of electron avalanches. A radiation entrance is provided so that radiation enters the conversion volume between the first and second electrode arrangements. In order to achieve well-defined avalanches the means for electron avalanche amplification includes a plurality of avalanche regions.

Abstract: A radiation detector including a chamber capable of being filled with an ionizable and scintillating substance, and a radiation entrance arranged such that radiation can enter said chamber partly for ionizing said ionizable and scintillating substance, partly for being converted into light therein, is disclosed. The detector further includes a light detector for detection of said light, and an electron avalanche detector for avalanche amplification and detection of electrons released as a result of the ionization. Further, there are provided means for correlating detected light and detected electrons, which are derivable from a single radiation photon; and means for producing a signal from the correlated detected light and detected electrons. The detector is particularly suitable for positron emission tomography (PET).

Abstract: An alternating electromagnetic field in the radiofrequency range is applied in a gaseous environment (4). Free electrons produced in the gas (4), by an ionising source of radiation (5) or by interaction of a charged particle beam with a specimen, are acted upon by the alternating electromagnetic field and undergo an oscillatory motion resulting in multiple collisions with the gas molecules or atoms. Amplified electron and photon signals are generated in a controlled discharge, proportional to the initial number of free electrons, and are collected by suitable means (6, 7, 8). The alternating field is generated either by electrodes (1, 2) biased with an alternating voltage, or by a coil driven by an AC current, and may be superposed with a static electric field. The detection device may be used with instruments such as electron microscopes, in ion beam technologies, and with instruments used for detection of ionising radiations such as proportional counters.

Abstract: A method and apparatus for radiography and also a detector for detecting incident radiation. In the method and the apparatus X-rays (9) are emitted from an X-ray source (60). The X-rays which have interfered with an object to be imaged are detected (62) in a detector (64). The detector (64), which detects incident radiation includes a gaseous avalanche chamber, including electrode arrangements between which a voltage is applied for creating an electrical field, which causes electron-ion avalanches of primary and secondary ionization electrons released by incident radiation.

Abstract: A detector for detection of ionizing radiation, and an apparatus for use in planar beam radiography, including such a detector. The detector includes a chamber filled with an ionizable gas. First and second electrode arrangements are provided in the chamber with a space therebetween. The space includes a conversion volume, an electron avalanche amplification unit arranged in the chamber, and at least one arrangement of read-out elements for detection of electron avalanches. To reduce the effect of possible spark discharges in the chamber, at least one of the first and second electrode arrangements includes a resistive material having a surface facing the other electrode arrangement.

Abstract: A detector (64) for detection of ionizing radiation, and an apparatus for use in planar beam radiography, including the detector (64). The detector (64) includes a chamber filled with an ionizable gas; first and second electrode arrangements (2, 1, 18, 19) provided in the chamber with a space between them, the space including a conversion volume (13); an electron avalanche amplification unit (17) arranged in the chamber; and, at least one arrangement of read-out elements (15) for detecting of electron avalanches. A radiation entrance is provided so that radiation enters the conversion volume between the first and second electrode arrangements. In order to achieve detectors which are simple to stack with each other, the first and second electrode arrangements exhibit a first and a second main plane, said planes being non-parallel. This permits stacked detectors to be manufactured simply and cost effectively.

Abstract: The present invention may provide a particle or radiation detector or imager which may be used for accurate recording of medical (2-D) X-ray images. The imager includes at least one detector panel. The detector panel includes a microgap detector with an array of pixel electrodes of a novel form. Each pixel electrode is insulated from a planar cathode by means of an insulating layer. Each pixel electrode is connected to an underlying contact by means of a via hole in the insulating layer. The insulating layer is preferably conformal with the electrodes. The underlying contact is connected to an electronic measuring element which preferably lies underneath the electrode and is about the same size as the electrode. The measuring element may be a storage device, a digital counter or similar. A switching transistor is connected to the measuring device. The switching transistor may be a thin film transistor. Alternatively, both measuring element and transistor may be formed in a single crystal semiconductor, e.g.

Abstract: A detection apparatus for detecting an electron cloud includes a resistive anode layer with a detection plane upon which the electron cloud is incident. The resistive layer is capacitively coupled to a readout structure having a conductive grid parallel to the detection plane. Charge on the resistive layer induces a charge on the readout structure, and currents in the grid. The location of the induced charge on the readout structure corresponds to the location on the detection plane at which the electron cloud is incident. Typically, the detection apparatus is part of a detector, such as a gas avalanche detector, in which the electron cloud is formed by conversion of a high-energy photon or particle to electrons that undergo avalanche multiplication. The spacing between the anode layer and the readout structure is selected so that the width of the charge distribution matches the pitch between conductive segments of the grid.

Abstract: Spectrally resolved detection of ionizing radiation in a detector comprising a chamber (13) filled with an ionizable substance, a radiation entrance (33), an electron avalanche amplification means, and a read-out arrangement (29), comprises introducing a broadband radiation beam (1) into the chamber between and in parallel first and second electrode arrangements for ionization of the ionizable substance and avalanche amplifying said electrons. By means of the read-out arrangement (29) electron avalanches (SX1, SX2, . . . SXN), derivable mainly from ionization in sections (X1, H2, . . . , XN) of the chamber that are separated in the direction of the introduced radiation beam, are separately detected. From spectrally resolved absorption data, weighting factors (W11, W21, . . . , WM1, W12, W22, . . . , WM2, . . . , W1N, W2N, . . . , WMN) for different spectral components (E1, E2, . . . , EM) of the radiation (1) and for different sections (X1, X2, . . .

Abstract: The apparatus and method provide a technique for improving detection of alpha and/or beta emitting sources on items or in locations using indirect means. The emission forms generate ions in a medium surrounding the item or location and the medium is then moved to a detecting location where the ions are discharged to give a measure of the emission levels. To increase the level of ions generated and render the system particularly applicable for narrow pipes and other forms of conduits, the medium pressure is increased above atmospheric pressure.

Abstract: The invention provides apparatus and methods which facilitate movement of an instrument relative to an item or location being monitored and/or the item or location relative to the instrument, whilst successfully excluding extraneous ions from the detection location. Thus, ions generated by emissions from the item or location can successfully be monitored during movement. The technique employs sealing to exclude such ions, for instance, through an electro-field which attracts and discharges the ions prior to their entering the detecting location and/or using a magnetic field configured to repel the ions away from the detecting location.

Abstract: An ultraviolet detector comprises a metal tubular member which hermetically encloses an anode and a cathode therein and is filled with a discharged gas introduced therein from a metal exhaust tube. After the anode and the cathode are enclosed within the tubular member, the ultraviolet detector can be made without being subjected to any glass fusing process. Accordingly, the inside of the sealed vessel V1 can be prevented from being contaminated with fluorine, whereby the ultraviolet detector with stable characteristics can be provided.