Abstract: An electrostatic concentrator for use in radon detection, comprising of a plastic sheet having conductive electrodes patterned onto the surface. The sheet is patterned and cut in such a way that it can be assembled into a three-dimensional shape (e.g. a cone), such that when a voltage is applied to the electrodes an electrostatic field is created for propelling radon progeny towards a sensor on which it can be detected.

Abstract: Systems, methods, and computer program products that are configured to account for tilt of a radiation measurement system are disclosed. In one embodiment, a system includes a scanning system with a radiation detector, the scanning system configured to enable movement of the radiation detector. The system also includes a non-transitory machine-readable medium storing instructions which, when executed by at least one programmable processor, cause the at least one programmable processor to perform various operations including moving the radiation detector through a first, second, and third vertical calibration path and recording a first, second, and third radiation detector response within 3 cm of a water surface, and controlling the scanning system to move the radiation detector through at least one measurement path that takes into account a scanning system tilt, the at least one measurement path determined based on at least the first, second, and third radiation detector responses.

Abstract: One embodiment provides an imaging device, including: an enclosure comprising a casing and a radiation lining arranged within the casing to provide a radiation shield, wherein the enclosure comprises a removable portion; a plurality of modular components being in communication with calibration code, wherein the calibration code calibrates the imaging device based upon information of the plurality of modular components; each of the plurality of modular components comprising a plurality of gamma detectors including semiconductor crystals and being removable from the imaging device; the plurality of modular components being arranged such that the plurality of gamma detectors are configured in an array configuration with each of the plurality of gamma detectors having a predetermined spacing from each other gamma detector; a plurality of electronic communication components, wherein the plurality of electronic communication components facilitate communication from each of the gamma detectors using a hierarchical c

Abstract: Methods and systems for detecting nuclear material concealed within an enclosure are provided. An ionized air density is measured at one or more locations outside of the enclosure. The presence of the concealed nuclear material is detected, for each of the one or more locations, based on a characteristic of the measured ionized air density indicative of concealed nuclear materials.

Abstract: A Geiger-Mueller charge particle rate measurement system includes a clock management unit in combination with multiple oscillators and rate feedback controller to allow for reactive switching between the different oscillator frequencies to optimize system use. Controlling the clock management unit to send the appropriate frequency (clock signal) to the timers in response to measured rate date from the rate feedback controller facilitates operation at different clock speeds, which helps reduce power consumption when operated at lower speeds.

Abstract: A fissile neutron detection system includes a neutron moderator and a neutron detector disposed proximate such that a majority of the surface area of the neutron moderator is disposed proximate the neutron detector. Fissile neutrons impinge upon and enter the neutron moderator where the energy level of the fissile neutron is reduced to that of a thermal neutron. The thermal neutron may exit the moderator in any direction. Maximizing the surface area of the neutron moderator that is proximate the neutron detector beneficially improves the reliability and accuracy of the fissile neutron detection system by increasing the percentage of thermal neutrons that exit the neutron moderator and enter the neutron detector.

Abstract: A detector module for detecting photons includes a detector formed from a semiconductive material, the detector having a first surface, an opposing second surface, and a plurality of sidewalls extending between the first and second surfaces, and a guard band coupled to the sidewalls, the guard band having a length that extends about a circumference of the detector, the guard band having a width that is greater than a thickness of the detector such that an upper rim segment of the guard band projects beyond the first surface of the detector, the upper rim segment being folded over a peripheral region of the first surface along the circumference of the detector, the guard band configured to reduce recombinations proximate to the edges of the detector.

Abstract: A Geiger-Mueller charge particle rate measurement system includes a clock management unit in combination with multiple oscillators and rate feedback controller to allow for reactive switching between the different oscillator frequencies to optimize system use. Controlling the clock management unit to send the appropriate frequency (clock signal) to the timers in response to measured rate date from the rate feedback controller facilitates operation at different clock speeds, which helps reduce power consumption when operated at lower speeds.

Abstract: A detector module for detecting photons includes a detector formed from a semiconductive material, the detector having a first surface, an opposing second surface, and a plurality of sidewalls extending between the first and second surfaces, and a guard band coupled to the sidewalls, the guard band having a length that extends about a circumference of the detector, the guard band having a width that is greater than a thickness of the detector such that an upper rim segment of the guard band projects beyond the first surface of the detector, the upper rim segment being folded over a peripheral region of the first surface along the circumference of the detector, the guard band configured to reduce recombinations proximate to the edges of the detector.

Abstract: The present invention relates to a dosimetry device for an energy particle beam from a source and including at least two ionization chambers, each of which includes a collector electrode and a polarization electrode, said electrodes in each ionization chamber being separated by a gap including a fluid, an energy beam from a single source passing through said ionization chambers, the device being characterized in that said ionization chambers have different charge collection efficiency factors. Said calculation algorithm for the dose rate deposited by said beam is based on the measurement of an output signal in each ionization chamber of the device and on a ?gain? factor related to a first ionization chamber, said ?gain? factor being theoretically predetermined on the basis of said intrinsic and/or extrinsic parameters of said ionization chambers.

Abstract: A smoke detector includes a drift chamber and an ionization chamber formed by a first electrode and a second electrode. Electric charges are generated by ionization of the air. The drift chamber separated from the ionization chamber by the second electrode. The smoke particles penetrates from the environment to a detector inside the drift chamber. The electrical potential of first electrode exceeds a critical electric potential value for generating a corona discharge in the vicinity of the first electrode. The second electrode has openings for the electric charges generated in the ionization chamber to move to the drift chamber. The electric potential of the second electrode allows the electric charges in the drift chamber to move from the second electrode to the third electrode. The electric field between the second and third electrodes is at least 100 times weaker than the electric field between the first and second electrodes.

Abstract: The invention relates to a method for radiation detection signal processing, and more particularly to a method capable of using a periodic signal to control the time of charging/discharging to a capacitor of an integrator. The method can be used for detecting the energy of incident photon of Gamma ray during the happening of an event while reducing dead time, and thereby, the count rate is increased. As the periodic signal is used as the signal for controlling the time of charging/discharging to a capacitor, the charging/discharging time of the integrator is no longer being controlled by the triggering time of the event, and thus, the present method is advantageous in that: the control method and circuit architecture are comparatively simpler since the charging/discharging time of the integrator no longer required to be controlled precisely, and thus the integration error due to insufficient resolution in delay element can be avoided.

Abstract: A system for assaying an eluate for Technetium-99m and Molybdenum-99 content includes an inner ionization chamber including a well configured to receive the eluate, an outer ionization chamber concentric with the inner ionization chamber, and attenuating material positioned between the inner and outer ionization chambers. A computing device is configured to determine a Technetium-99m content of the eluate based on a first current measured in the inner ionization chamber, and determine a Molybdenum-99 content of the eluate based on at least a second current measured in the outer ionization chamber.

Abstract: Particle therapy systems and methods for particle dose imaging are provided. A particle therapy system includes a particle beam source for generating a particle beam; and at least one particle detector including an ionization chamber having a mesh electrode. The at least one particle detector is configured to receive the particle beam and to generate an ionization current responsive to the received particle beam. The ionization current may be used to characterize the particle beam.

Abstract: A position-sensitive ionizing-radiation counting detector includes a first substrate and a second substrate, and a defined gas gap between the first substrate and the second substrate. The first and second substrates comprise dielectrics and a discharge gas is contained between the first and second substrate. A microcavity structure comprising microcavities is coupled to the second substrate. An anode electrode is coupled to the first substrate and a cathode electrode is coupled to the microcavity structure on the second substrate. The detector further includes pixels defined by a microcavity and an anode electrode coupled to a cathode electrode, and a resistor coupled to each of the cathode electrodes. Each pixel may output a gas discharge counting event pulse upon interaction with ionizing-radiation. The detector further includes a voltage bus coupled to each of the resistors and a power supply coupled to at least one of the electrodes.

Abstract: A system for assaying an eluate for Technetium-99m and Molybdenum-99 content includes an inner ionization chamber including a well configured to receive the eluate, an outer ionization chamber concentric with the inner ionization chamber, and attenuating material positioned between the inner and outer ionization chambers. A computing device is configured to determine a Technetium-99m content of the eluate based on a first current measured in the inner ionization chamber, and determine a Molybdenum-99 content of the eluate based on at least a second current measured in the outer ionization chamber.

Abstract: A radiation detector includes a housing to contain a radiation detecting gas. The housing has a first thermal expansion over an operating temperature range. An elongate electrode extends within the housing and has opposing first and second ends, with the first end secured to adjacent portion of the housing. The elongate electrode has second thermal expansion over the operating temperature range defining a difference with respect to the first thermal expansion. A temperature compensator is coupled between the second end of the elongate electrode and an adjacent portion of the housing. The temperature compensator has a third thermal expansion over the operating temperature range to maintain a tension on the elongate electrode within a desired range over the operating temperature range.

Abstract: A system for assaying an eluate for Technetium-99m and Molybdenum-99 content includes an inner ionization chamber including a well configured to receive the eluate, an outer ionization chamber concentric with the inner ionization chamber, and attenuating material positioned between the inner and outer ionization chambers. A computing device is configured to determine a Technetium-99m content of the eluate based on a first current measured in the inner ionization chamber, and determine a Molybdenum-99 content of the eluate based on at least a second current measured in the outer ionization chamber.

Abstract: A radiation detection apparatus includes a radiation detection unit that detects a first intensity of a radiation that has been transmitted through an inspection target to generate a first measurement value, the inspection target being disposed between a radiation source that irradiates the radiation and the radiation detection unit, a transmission ionization chamber that detects a second intensity of the radiation that has not reached the inspection target to generate a second measurement value, the transmission ionization chamber having an enclosed structure, the transmission ionization chamber being disposed between the radiation source and the inspection target, the transmission ionization chamber including an entrance window through which the radiation enters the transmission ionization chamber and an exit window through which the radiation goes out of the transmission ionization chamber, and an operation unit that calculates a physical quantity of the inspection target.

Abstract: The present invention relates to apparatus and methods for use in highly sensitive and efficient neutron detection, that includes using trigger reactions to initiate far-ultraviolet (FUV) optical emissions. In some embodiments of the present invention, a method for the detection of slow neutrons includes absorption of a slow neutron with a high neutron capture-cross-section nucleus, decay of the compound nucleus into energetic particles, creation of excimers from the energetic particles reacting with a background gas to form excimers, radiative decay of excimers resulting in emission of FUV radiation, and detection of the FUV radiation using an optical detector.

Abstract: A radiation monitor includes an ionization chamber for detecting radiation that passes into the ionization chamber. The ionization chamber generates a current flow in response to the detected radiation. An electrometer is electrically connected to the ionization chamber for measuring the current flow generated by the ionization chamber. The electrometer is operable in a plurality of modes based on a magnitude of the current flow generated by the ionization chamber. A method of measuring current flow through an electrometer of a radiation monitor is also provided.

Abstract: A radiation detection assembly includes an ionization chamber for detecting radiation. The ionization chamber includes a volume of pressurized gas. An exterior enclosure houses the ionization chamber within an interior volume. The exterior enclosure includes a frangible section. A relief assembly defines a gas flow path from the ionization chamber to the frangible section of the exterior enclosure. The frangible section releases pressure from within the ionization chamber when the pressurized gas within the ionization chamber exceeds a predetermined pressure such that at least some of the pressurized gas flows through the relief assembly and through the frangible section of the exterior enclosure. The pressurized gas is then released to an exterior of the exterior enclosure. A method of reducing pressure within a radiation detection assembly is also provided.

Abstract: Apparatus and method for separating neutron-induced 4He (or other nuclei) recoil from background, which is predominantly gamma-ray induced electrons and cosmic rays, using software analysis of digitized electrical pulses generated in a six tube, high-pressure (11 bar) helium-4 (4He) detector, are described. Individual electrical pulses from the detector were recorded using a 12-bit digitizer, and differences in pulse rise time and amplitudes, due to different energy loss of neutrons and gamma rays, are used for neutron/gamma ray separation.

Abstract: Systems and methods for the detection, analysis, and collection of rare cellular events, wherein rare cellular events are defined by events comprising less than 5% of a total number of cells in a sample. The systems and methods generally include: (1) a flow cell dimensioned so as to permit a flow of a sample through the flow cell at a flow rate greater than 300,000 cells per second; (2) a laser positioned to emit a laser beam directed to the flow cell; (3) one or more deflector components disposed between the laser and the flow cell, wherein the deflector component is configured to affect a position of the laser beam relative to the sample flow; (4) one or more fluorescence emission detectors; and (5) one or more processor configured to detect rare cellular events based on fluorescence emission from cell-binding surface markers introduced into the sample prior to the sample being flowed through the flow cell.

Abstract: Apparatus and method for detecting radiation-of-interest, such as neutron radiation, employs a gas chamber, a gas that responds to ionizing particles by producing electrons and ions, a cathode that attracts ions, and a supporting layer with a conductive pathway. The conductive pathway collects electrons and responds to electrons that drift towards the conductive pathway by inducing production of further electrons and ions within the gas. The electrons that are collected at the conductive pathway and/or the ions that drift away from the conductive pathway will induce an electrical signal, which can be used to detect the radiation-of-interest.

Abstract: A beta radiation monitor (70,90), comprising a gas flow proportional detector (60) for detecting beta radiation emitted by a beta emitter external to the detector; a fill gas supply (51) configured to supply a fill gas to the detector, wherein the fill gas comprises nitrogen; a temperature sensor (72) for measuring temperature; and a controller (64) in communication with the temperature sensor for adjusting an operational parameter of the monitor in accordance with the measured temperature. The operational parameter may comprise a voltage applied across the fill gas, which may be thermistor controlled, or a beta radiation detection threshold of the detector. The fill gas is supplied by a nitrogen generator. The gas flow proportional detector may be a large-area detector.

Abstract: A radiation detector is formed from a plasma panel that includes a front substrate, and a back substrate that forms a generally parallel gap with the front substrate. X (column) and Y (row) electrodes are coupled by gas discharge events to define one or more pixels. Impedances are coupled to the X and Y electrodes, and a power supply is coupled to one or both types of electrodes. Discharge event detectors are coupled to the impedances.

Abstract: A shock wave in a gas is modified by emitting energy to form an extended path in the gas; heating gas along the path to form a volume of heated gas expanding outwardly from the path; and directing a path. The volume of heated gas passes through the shock wave and modifies the shock wave. This eliminates or reduces a pressure difference between gas on opposite sides of the shock wave. Electromagnetic, microwaves and/or electric discharge can be used to heat the gas along the path. This application has uses in reducing the drag on a body passing through the gas, noise reduction, controlling amount of gas into a propulsion system, and steering a body through the gas. An apparatus is also disclosed.

Abstract: A method for measuring high-energy radiation flux, comprising applying a low voltage to electrodes in an ion chamber filled with a fluid capable of forming ions through the interaction of the fluid with high energy radiation; measuring an ion current signal related to an ion current induced by the low voltage; determining a leakage current; determining a gain; determining a magnitude of the high-energy radiation flux based on the ion current signal, gain, and leakage current; and outputting the result of the magnitude of the high-energy radiation flux.

Abstract: A three dimensional radiation measurement scanning system includes a circular drive operable with horizontal and vertical drives for moving a radiation detector through first, second and third orthogonal axes in a three dimensional scanning of the detector in a water tank. Motor are coupled to the drives and activated by a controller for providing the movement of the radiation detector which providing radiation field sensing signals for locations of the detector throughout the tank. A reference detector is fixed for comparing its radiation field measurements with those of the scanned radiation detector. An offset mount carries the radiation detector allowing it to be extended beyond the circular ring gear during horizontal movement of the radiation detector and thus position the radiation detector at wall surfaces of the water tank.

Abstract: A method of generating a signal representing with an ion energy analyzer for use in determining an ion energy distribution of a plasma. The ion energy analyzer, used for determining an ion energy distribution of a plasma, includes a first grid and a second grid that is spaced away from and electrically isolated from the first grid. The first grid forms a first surface of the ion energy analyzer and is positioned to be exposed to the plasma. The first grid includes a first plurality of openings, which are dimensioned to be less than a Debye length for the plasma. A voltage source and an ion current meter are operably coupled to the second grid, the latter of which is configured to measure an ion flux onto the ion collector and to transmit a signal that represents the measured ion flux. The method includes selectively and variably biasing the second grid relative to the first grid.

Abstract: In one embodiment of the invention, a method for irradiating a target is disclosed. A proton beam is generated using a cyclotron. A first information is provided to an energy selection system. An energy level for the protons is selected using an energy selection system based on the first information. The first information comprises a depth of said target. The proton beam is routed from the cyclotron through a beam transfer line to a scanning system. A second information is provided to the scanning system. The second information comprises a pair of transversal coordinates. The proton beam is guided to a location on the target determined by the second information using a magnet structure. The target is irradiated with the protons.

Abstract: A position-sensitive radiation counting detector includes a first and a second substrate. A gas is contained within the gap between the substrates. A photocathode layer is coupled to one side of the first substrate and faces the second substrate. A first electrode is coupled to the second substrate and a second electrode is electrically coupled to the first electrode. A first impedance is coupled to the first electrode and a second impedance is coupled to the second electrode. A power supply is coupled to at least one electrode. A first discharge event detector is coupled to the first impedance and a second discharge event detector is coupled to the second impedance. The radiation counting detector further includes a plurality of pixels, each capable of outputting a gas discharge pulse upon interaction with radiation received from the photocathode.

Abstract: The present invention relates to apparatus and methods for use in highly sensitive and efficient neutron detection, that includes using trigger reactions to initiate far-ultraviolet (FUV) optical emissions. In some embodiments of the present invention, a method for the detection of slow neutrons includes absorption of a slow neutron with a high neutron capture-cross-section nucleus, decay of the compound nucleus into energetic particles, creation of excimers from the energetic particles reacting with a background gas to form excimers, radiative decay of excimers resulting in emission of FUV radiation, and detection of the FUV radiation using an optical detector.

Abstract: A method for measuring high-energy radiation flux, comprising applying a low voltage to electrodes in an ion chamber filled with a fluid capable of forming ions through the interaction of the fluid with high energy radiation; measuring an ion current signal related to an ion current induced by the low voltage; determining a leakage current; determining a gain; determining a magnitude of the high-energy radiation flux based on the ion current signal, gain, and leakage current; and outputting the result of the magnitude of the high-energy radiation flux.

Abstract: A beta radiation monitor (70,90), comprising a gas flow proportional detector (60) for detecting beta radiation emitted by a beta emitter external to the detector; a fill gas supply (51) configured to supply a fill gas to the detector, wherein the fill gas comprises nitrogen; a temperature sensor (72) for measuring temperature; and a controller (64) in communication with the temperature sensor for adjusting an operational parameter of the monitor in accordance with the measured temperature. The operational parameter may comprise a voltage applied across the fill gas, which may be thermistor controlled, or a beta radiation detection threshold of the detector. The fill gas is supplied by a nitrogen generator. The gas flow proportional detector may be a large-area detector.

Abstract: An apparatus for detecting at least one of neutron and gamma ray reception and outputting a signal indicative of the reception. A detector is responsive to the at least one of neutron and gamma ray reception. The detector has a cathode, an anode separated by a space from the cathode, and a gas within the separating space. Charge is generated within the gas upon the at least one of neutron and gamma ray reception at the cathode and the charge passes to the anode as a detection. A processing arrangement is operatively connected to the anode for outputting the signal indicative of the detection. A light irradiation arrangement for introducing a light irradiation causes charge within the gas that replicates the charge generated upon detection and that causes output of a signal that replicates the signal indicative of the detection.

Abstract: A dosimetry device for charged particle radiation that can be exclusive of cables and connectors between substrates is provided. A plurality of first electrodes are formed on one surface of a printed circuit board, a second electrode substrate having a second electrode opposing each of the plurality of first electrodes through an ionized space is provided, and a signal processing circuit is provided on the other surface opposing the surface of the printed circuit board. The signal processing circuit includes at least one amplifying circuit, a plurality of integrating capacitors corresponding to the amplifying circuit for integrating charge at each corresponding one of the first electrodes, and at least one selector switch that switchably connects each of the integrating capacitors to the amplifying circuit. The printed circuit board may be a multi-layer printed circuit board.

Abstract: A radiation detection apparatus includes a radiation detection unit that detects a first intensity of a radiation that has been transmitted through an inspection target to generate a first measurement value, the inspection target being disposed between a radiation source that irradiates the radiation and the radiation detection unit, a transmission ionization chamber that detects a second intensity of the radiation that has not reached the inspection target to generate a second measurement value, the transmission ionization chamber having an enclosed structure, the transmission ionization chamber being disposed between the radiation source and the inspection target, the transmission ionization chamber including an entrance window through which the radiation enters the transmission ionization chamber and an exit window through which the radiation goes out of the transmission ionization chamber, and an operation unit that calculates a physical quantity of the inspection target.

Abstract: An ionization detector having a grid of electrodes disposed perpendicular to an oscillating voltage. Charge released from an ionization event oscillates in the detector medium at the same frequency as the applied oscillating voltage. The electrode grid is configured to measure induced oscillating charge from the oscillating ionization charge in the detector. The detector signal is obtained from readout of the induced oscillating charge on the electrodes. Signal processing electronics processes the measured signal from the oscillating induced charge to derive energy and position information of the ionization event. A bias voltage is applied across the detector to further sweep the ionization charge from the active detection volume.

Abstract: It is an object of the invention to develop a generic method for identification of gases and a corresponding device, which has a simple structure and allows immediate and simultaneous detection of the chemical compounds to be tested, and which uses for identification the material-specific mobility and simultaneously the change in this mobility as a function of the electric field strength. This is achieved in that due to the resulting electric field, each ionized molecule has a drift velocity which is partially increased or decreased, wherein the resulting electric field is a DC field, on which an asymmetric AC field is superimposed. These methods and associated devices for the detection and identification of gases are used to identify and detect chemical compounds, in particular explosive and/or unhealthy substances or compounds, which must be detected in very small concentrations.

Abstract: A radiation detector is formed from a plasma panel that includes a front substrate, and a back substrate that forms a generally parallel gap with the front substrate. X (column) and Y (row) electrodes are coupled by gas discharge events to define one or more pixels. Impedances are coupled to the X and Y electrodes, and a power supply is coupled to one or both types of electrodes. Discharge event detectors are coupled to the impedances.

Abstract: A radiation counting detector includes a first substrate and a second substrate that is generally parallel to first substrate and forms a gap with the first substrate. A gas is contained within the gap. A photocathode layer is coupled to one side of the first substrate and faces the second substrate. A first electrode is coupled to the second substrate and a second electrode is electrically coupled to the first electrode. A first impedance is coupled to the first electrode and a second impedance is coupled to the second electrode. A power supply is coupled to at least one of the electrodes. A first discharge event detector is coupled to the first impedance and a second discharge event detector is coupled to the second impedance. The radiation counting detector further includes a plurality of pixels, each capable of outputting a gas discharge pulse upon interaction with radiation received from the photocathode. Each gas discharge pulse is counted as having an approximately equal value.

Abstract: A method of and apparatus for identifying the presence of thin photocatalytic (PCAT) coatings on glass surfaces. An apparatus is disclosed that can determine whether a PCAT coating (which may comprise titanium dioxide, for example) having a thickness of less than about 100 ? is present on the surface of a substrate such as glass. The apparatus may measure the reflectance of electromagnetic energy (such as light energy) at the surface of a substrate using energy at selected wavelengths or wavelength ranges. The apparatus may determine reflectance values for PCAT coated surfaces of any thickness, as well as for uncoated surfaces.

Abstract: Method and apparatus is provided for monitoring an item for radioactive material on or associated with the item, the apparatus including an enclosed volume, an item monitoring location, a detection location, ion detectors provided within the detection location, a mover of gas for providing a flow of gas past the item monitoring location to a detection location, so as to revel the level and/or presence of radioactive material on the item. The item may be supported within the monitoring location by one or more rollers to ease its insertion and/or removal. The item monitoring location may be extremely elongate so as to measure pipes and the like. Various designs of roller and gas flow controllers are provided to optimize monitoring.

Abstract: A novel method for measuring airborne radon and thoron capable of separately measuring radon and thoron with high sensitivity, having a small-sized device structure, and free of the influence from its measurement environment. In the method, by measuring Cherenkov light generated when airborne radon and thoron are adsorbed to an absorbent and then ? rays emitted in process of disintegrations of radon and thoron pass through the absorbent, radon and thoron are measured. Based on a decay time of the Cherenkov light, a mixture ratio between radon and thoron is measured. As the absorbent, porous glass is preferably employed which is provided with fine pores of 0.3 to 30 nm in diameter.

Abstract: A plasma panel based ionizing-photon radiation detector includes an input and output substrate with gamma-ray to free-electron conversion occurring primarily on the input plate and a sealed discharge gas between the substrates. X-electrodes and Y-electrodes are formed on the two substrates and configured to form a plurality of pixels. Impedances are coupled to the X and Y electrodes and a power supply is coupled to the X-electrodes. Discharge event detectors coupled to impedances detect discharge events on the Y electrodes and at the pixel locations, which leads to the detection of ionizing-photon radiation.

Abstract: An array gas electron multiplier (GEM) digital imaging radiation detector and a control method thereof are disclosed. The array gas electron multiplier (GEM) digital imaging radiation detector includes an array GEM detector. The array GEM detector includes: an ionized electron generation unit for generating ionized electrons in internal filling gas by incident X-rays or gamma rays or by incident charged particles; a gas electron multiplication unit for multiplying the ionized electrons of the ionized electron generation unit in filling gas inside hole of a gas electron multiplier (GEM), through electron avalanche effect, using the GEM, to form electron clouds; a readout for detecting and outputting coordinates of the electron clouds as the readout receives positions through electrical signals, in which the positions of the electron clouds, being multiplied and formed in the gas electron multiplication unit, reach output electrodes.

Abstract: The present invention relates to a method of increasing the conversion efficiency of an EUV and/or soft X-ray lamp, in which a discharge plasma (8) emitting EUV radiation or soft X-rays is generated in a gaseous medium formed by an evaporated liquid material in a discharge space, said liquid material being provided on a surface in the discharge space and being at least partially evaporated by an energy beam (9). The invention also refers to a corresponding apparatus for producing EUV radiation and/or soft X-rays. In the method, a gas (11) composed of chemical elements having a lower mass number than chemical elements of the liquid material is supplied through at least one nozzle (10) in a directed manner to the discharge space and/or to the liquid material on a supply path to the discharge space in order to reduce the density of the evaporated liquid material in the discharge space. With the present method and corresponding apparatus the conversion efficiency of the lamp is increased.

Abstract: A method for routine monitoring and quality assurance of field asymmetry of high energy circular radiation beam producing equipment. The quality assurance process of field symmetry for devices such as stereotactic radiosurgery (SRS) systems is simplified by directly measuring the integration of the half-beam profile. The method of the invention provides that the field symmetry is obtained by positioning the tip of an ion chamber, with a collecting length approximately half the diameter of the beam, at the central axis of the beam, and rotating the ion chamber at varying angular positions, acquiring and comparing readings at desired angular positions. Each pair of readings from positions 180 degrees opposed from each other, are plugged into the equation, Asymmetry=2(R1?R2)/(R1+R2) to compute asymmetry.