Abstract: A radiation beam analyzer for measuring the distribution and intensity of radiation produced by a Cyberknife®. The analyzer employs a relative small tank of water into which a sensor is placed to maintain a constant SAD (source to axis distance). A first method maintains a fixed position of detector, and raises or lowers the small tank of water. A second method moves the detector up, down or rotationally synchronously in opposite directions with respect to the small tank of water to keep the SAD constant. These methods position the detector relative to the radiation source to simulate the location of a malady within a patient's body. An embodiment of the present invention enables measurements of substantially larger fields.

Abstract: The readout electrode assembly of an avalanche particle detector can be effectively protected against sparks and discharges by means of a plurality of resistor pads formed in a dielectric cover layer above the readout pads. The resistor pads may either be connected directly to the readout pads, or may be coupled capacitively by means of a charge spreading pad embedded into the dielectric cover layer and spatially separated from the readout pads. The charge spreading pad allows the distribution of charges to neighboring readout pads, and may hence increase the spatial resolution of the detector device.

Abstract: Nested ionization chambers provide independent measurements of a radiation beam that does not fully irradiate the volume of one or both chambers. By mathematically combining these independent measurements, partial volume effects caused by a change in ionization detector calibrations when the full detector volume is not irradiated by the radiation beam, may be decreased, providing more accurate measurement of extremely small radiation beams.

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 system may include a conductive substrate, a plurality of conductive nanostructures disposed on a first side of the conductive substrate, an insulating substrate, and a plurality of electrodes disposed on a first side of the insulating substrate. The first side of the conductive substrate faces the first side of the insulating substrate, and each of the plurality of electrodes is electrically connected to the conductive substrate. In other aspects, a system may include a first insulating substrate and a second insulating substrate, where a first side of the first insulating substrate faces a first side of the second insulating substrate, and each of a first plurality of electrodes is electrically connected to a respective one of a second plurality of electrodes.

Abstract: To attain objects to reduce the spread of electrons as compared with a conventional one without degrading the multiplication factor of electrons; to provide a large electron multiplication factor; and to improve positional resolution, there is provided a gas electron multiplier using interaction between radiation and gas through photoelectric effects including: a chamber filled with gas and a single gas electron multiplication foil arranged in the chamber wherein the gas electron multiplication foil is made of a plate-like multilayer body composed by having a plate-like insulation layer made of a macromolecular polymer material having a thickness of around 100 ?m to 300 ?m and flat metal layers overlaid on both surfaces of the insulation layer, and the plate-like multilayer body is provided with a through-hole structure.

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 beam analyzer for measuring the distribution and intensity of radiation produced by a Cyberknife®. The analyzer employs a relative small tank of water into which a sensor is placed. The distance between the sensor and the radiation source is not varied. There are two methods to maintain the SAD (source to axis distance) constant. A first method maintains the position of detector fixed, utilizing a holder designed to retain the detector, and raises or lowers the small tank of water. A second method moves the detector up or down with a raising and lower mechanism in one direction and synchronically moves the small tank of water in the opposite direction with another raising and lowering mechanism. The second method also keeps the SAD constant. These methods position the detector relative to the radiation source to simulate the location of a malady within a patient's body.

Abstract: An ionizing radiation detection system can include a self-quenching sensing element having a substantially sealed enclosure containing a plurality of gases. The plurality of gases can include an ionizing gas to ionize in response to receiving a particle of ionizing radiation. The plurality of gases can also include a halogen quenching gas. In a particular embodiment, the plurality of gases can include an oxygen-containing gas in an amount of at least approximately 5% by pressure of a total pressure of the plurality of gases. In another particular embodiment, the partial pressure of the oxygen-containing gas can be from approximately 2666 Pa to approximately 16000 Pa. In another embodiment, the radiation detection system can include an anode having a composition that is more resistant to erosion by gasses within the sensing element.

Abstract: A radiation beam analyzer for measuring the distribution and intensity of radiation produced by a CyberKnife®. The analyzer employs a relative small tank of water into which a sensor is placed. The distance between the sensor and the radiation source is not varied. The tank of water is raised and lowered relative to the sensor to simulate the location of a malady within a patient's body. This movement of the tank permits the radiation from the CyberKnife® to be properly calibrated and adjusted for a proper treatment of a malady in a patient.

Abstract: An economical position-sensing muon detector for muon radiography is constructed using a pair of glass plates spaced apart by crossed parallel barriers. Smaller detector wires are interspersed between the barriers and an ionizing gas is used to fill the space between the plates. A muon striking near where detector wires cross causes a local momentary current flow. The current flow in two of the detector wires is sensed to determine the coordinates of the muon impact. Such muon detectors can be assembled in modular surface arrays and such arrays can be positioned on spatial surfaces for differential inspection and detection of muons transiting through and emanating from objects placed within the inspection space. Such a detector constitutes a novel and useful invention in providing an inspection device and means for cargo or cargo vehicles that detects muons transiting through and emanating from hazardous materials intended to cause malicious harm.

Abstract: The invention provides methods and apparatus for detecting radiation including x-ray photon (including gamma ray photon) and particle radiation for radiographic imaging (including conventional CT and radiation therapy portal and CT), nuclear medicine, material composition analysis, container inspection, mine detection, remediation, high energy physics, and astronomy. This invention provides novel face-on, edge-on, edge-on sub-aperture resolution (SAR), and face-on SAR scintillator detectors, designs and systems for enhanced slit and slot scan radiographic imaging suitable for medical, industrial, Homeland Security, and scientific applications. Some of these detector designs are readily extended for use as area detectors, including cross-coupled arrays, gas detectors, and Compton gamma cameras. Energy integration, photon counting, and limited energy resolution readout capabilities are described.

Abstract: A data processing device, comprising a plurality of emitter antennas arranged on a movable data acquisition device and adapted to emit electromagnetic radiation including data acquired by the movable data acquisition device, a plurality of receiver antennas each adapted to receive the electromagnetic radiation emitted by each of the plurality of emitter antennas, and a data processing unit coupled to the plurality of receiver antennas and adapted to extract the data acquired by the movable data acquisition device from the electromagnetic radiation received by the plurality of receiver antennas.

Abstract: A radiation detection device comprising a plasma display panel (PDP) with a multiplicity of radiation detection pixels, each radiation detection pixel being defined by a hollow elongated Plasma-tube filled with an ionizable gas. Arrays of Plasma-tubes are positioned on a suitable base such as a substrate and used to inspect and detect radiation from a selected object. Each Plasma-tube may be of any suitable geometric configuration and may be used alone or in any combination with one or more Plasma-shells, such as a Plasma-disc, Plasma-dome, and/or Plasma-sphere. Luminescent material may be positioned near or on each Plasma-tube or Plasma-shell to provide or enhance light output. A flexible base substrate may be used to wrap a layer or blanket of radiation detection Plasma-tubes about the selected object. The substrate base may comprise an elongated rod that is used as a probe to detect radiation from an object. An object may be passed through a ring or a cylinder of Plasma-tubes.

Abstract: A radiation beam analyzer for measuring the distribution and intensity of radiation produced by a CyberKnife®. The analyzer employs a relative small tank of water into which a sensor is placed. The distance between the sensor and the radiation source is not varied. The tank of water is raised and lowered relative to the sensor to simulate the location of a malady within a patient's body. This movement of the tank permits the radiation from the CyberKnife® to be properly calibrated and adjusted for a proper treatment of a malady in a patient. In a second embodiment a radiation beam analyzer measures the distribution and intensity of radiation produced by a radiation source. The analyzer employs a relative small tank of water into which a sensor or detector is placed. The distance between the sensor and the radiation source is not varied. There are two methods to maintain the SAD (source to axis distance) constant.

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 high strength window for a radiation detection system includes a plurality of intersecting ribs defining a grid having openings therein with tops of the ribs terminate substantially in a common plane. The intersecting ribs are oriented non-perpendicularly with respect to each other and define non-rectangular openings. The window also includes a support frame around a perimeter of the plurality of intersecting ribs, and a film disposed over and spanning the plurality of intersecting ribs and openings. The film is configured to pass radiation therethrough. An associated radiation detection system includes a sensor disposed behind the window. The sensor is configured to detect radiation passing through the high strength window.

Abstract: A micro-sized gas detecting device with two electrodes separated by a gap of width ranging from 1 to 500 microns, where the detection is based on emission spectroscopy of gases in an electric discharge across the gap (discharge region) as the gas flows through the region. The characteristic light emitted by molecules during the discharge can be detected directly with photodiodes or transferred through optical fiber and detected with remote optical sensing components. The device can have single or multiple discharge regions in an array so that light emitted can be monitored at different wavelengths simultaneously. The device can operate under gaseous pressure ranging from a few milli-Torr to a few atmospheres. The device consumes little power (50 mW-100 mW) and can be powered with an alternating current and has the potential to be battery powered.

Abstract: The present invention provides a digital imaging photodetector with a gas electron multiplier. The digital imaging photodetector comprises a gas electron multiplier detector. The gas electron multiplier detector includes a photoelectric converter for converting incident light into photoelectrons or Compton electrons; a gas electron multiplier (GEM) for receiving the photoelectrons or Compton electrons from the photoelectric converter and multiplying them; and a readout unit for receiving an electrical signal indicating a position where an electron cloud multiplied in the gas electron multiplier arrives on an anode, recognizing coordinates of the electron cloud based on the received signal, and outputting the coordinates of the electron cloud.

Abstract: A microwave or terahertz and neutron radiation type detector, which uses an orbitron as a radiation source. The detector may have a polarity switching apparatus to enable the orbitron to selectively change from between short wave to neutron emission functions. A highly compact and lightweight identifier of explosives and other chemicals, which may be so small and light as to be hand held, and which is effective at stand-off distances, is thereby provided.

Abstract: The present invention includes a high-energy detector having a cathode chamber, a support member, and anode segments. The cathode chamber extends along a longitudinal axis. The support member is fixed within the cathode chamber and extends from the first end of the cathode chamber to the second end of the cathode chamber. The anode segments are supported by the support member and are spaced along the longitudinal surface of the support member. The anode segments are configured to generate at least a first electrical signal in response to electrons impinging thereon.

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 microscale planar device for detecting particles under high pressure with high sensitivity. The device may have an anode and cathode with an insulator situated between them. The insulator may have a number of holes, cavities or channels between the anode and cathode. There may be conductive rings at the perimeters of openings of the channels on the anode side of the insulator. These rings may be a part of the anode. An ion may be attracted into one of the channels where it interacts with a gas to result in an avalanche breakdown. The breakdown may be detected by instrumentation connected to the anode and cathode. The lateral and/or longitudinal dimensions of the channels may be such that the device may operate as a detector with ambient air as a gas under its pressure of about one atmosphere.

Abstract: A radiation detector using gas amplification includes: a first electrode pattern which is formed on a first surface of an insulating member and has a plurality of circular openings; and a second electrode pattern which is formed on a second surface of the insulating member opposite to the first surface thereof and has convex portions of which respective forefronts are exposed to centers of the openings of the first electrode pattern; wherein a predetermined electric potential is set between the first electrode pattern and the second electrode pattern; wherein edges of the first electrode pattern exposing to the openings are shaped in respective continuous first curved surfaces by covering the edges thereof with a first solder material.

Abstract: The invention relates to a detector for detecting electrically neutral particles. The detector has a housing (10) filled with a counting gas. A converter (22) in the housing (10) generates conversion products as a result of the absorption of the neutral particles. The conversion products generate electrically charged particles in the counting gas, and a readout device (19) detects the electrically charged particles. A device (18) generates an electrical drift field for the electrically charged particles in a region of the volume of the counting gas so that at least some of the electrically charged particles drift toward the readout device (19). The converter device (22) is of charge-transparent design and being arranged in the detector housing (10) so that the drift field passes through at least part of this device.

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: In use of a UV gas discharge tube (such as used in flame monitoring apparatus), an electric field is periodically applied in the tube, each application of the field being followed by an ‘off’ period in which the field is removed. During this process, the mean value of the statistical lag Ts is measured over a predetermined time duration (the statistical lag is the time lag after each application of the electric field to the tube before conduction (if any) takes place). If the statistical lag lies within region I, the flame is judged to be present. If the statistical lag lies in region II, the flame is judged to be off (and a warning may be signalled). If the statistical lag lies in region III, a fault in the tube is signalled. This may be a “field emission” fault whereby free electrons are generated by the applied electric field, without the presence of UV radiation or it may be a “multiple counting” fault.

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: The present invention provides an orofacial radiation detection device for detection of radionuclide contamination from inhalation. The device includes a face mask including a support frame and an adjustable head strap connected to the support frame. Mounted on the frame are radiation detectors in selected locations so that when being worn by a person, the detectors are located in close proximity to the orofacial region of the person including their nose and mouth. The device includes an electronic controller connected to the detectors for controlling operation of the radiation detectors. The device includes a microcomputer mounted on the support frame and electrically connected to the electronic controller for processing signals from the detectors for allowing input from an operator, performing data analysis and detection algorithms, and outputting results.

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: To attain objects to reduce the spread of electrons as compared with a conventional one without degrading the multiplication factor of electrons; to provide a large electron multiplication factor; and to improve positional resolution, there is provided a gas electron multiplier using interaction between radiation and gas through photoelectric effects including: a chamber filled with gas and a single gas electron multiplication foil arranged in the chamber wherein the gas electron multiplication foil is made of a plate-like multilayer body composed by having a plate-like insulation layer made of a macromolecular polymer material having a thickness of around 100 ?m to 300 ?m and flat metal layers overlaid on both surfaces of the insulation layer, and the plate-like multilayer body is provided with a through-hole structure.

Abstract: An instrument for checking quality of therapeutic x-ray and electron radiation provides modes optimized for both electrons and for photons obtained by physically flipping the unit to interpose the necessary build-up material between the radiation beam and contained detectors. The invention provides an improved method of constructing ionization detectors for improved energy discrimination using such detectors and wire-free operation.

Abstract: A measuring method that utilizes a bandpass filter and a measurement apparatus to measure an intensity of light having a predetermined wavelength among lights emitted from a light source, the bandpass filter transmitting the light having the predetermined wavelength, the measurement apparatus measuring an absolute intensity of an incident light includes the steps of measuring an output of the measurement apparatus continuously, stopping or starting an emission of the light source in the measuring step, calculating a first extreme value t?t0?0 and a second extreme value t?t0+0 in the output of the measurement apparatus at time t0 where t is time in the measuring step, and t0 is time when the emission of the light source stops; and calculating a difference between the first extreme value t?t0?0 and the second extreme value t?t0+0.

Abstract: A radiation detector is provided having an anode wire formed of an amorphous metal alloy. In one embodiment the radiation detector comprises a cathode assembly. The cathode assembly includes a main portion, a first end and a second end, where the first end opposes the second end. The cathode assembly also includes a radiation interacting material. An anode extends within the cathode assembly from the first end to the second end, and the anode is comprised of an amorphous metal alloy.

Abstract: A dosimeter based on a gas electron multiplier and method of use thereof for measurement of doses of therapeutic radiation to which a tissue-phantom is exposed. Subsequent to the in-phantom measurement and verification of radiation beam delivery, radiation can be effectively delivered to a human target organ, based on the verification of radiation quantities to which the phantom was exposed. Use of a gas electron multiplier-based dosimeter facilitates precise and accurate verification of the radiation dose within a phantom by taking measurements in real time, with no need for subsequent film processing.

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: The present invention relates to a device for detecting unauthorized product in a protected access area, which comprises, in combination: a support base (100) designed to receive a single foot, covered with its shoe, of an individual to be checked, positioning marking means, on the support base (100), for imposing an exact positioning of the foot covered with its shoe, means of detecting ionizing or radioactive radiation (500), positioned under the support base (100) on the side opposite (105) to that comprising the positioning marking means (400), to provide an indication linked to the presence or the absence of a product emitting an ionizing or radioactive radiation in an area of the individual between the sole of the shoe and the knee of the individual to be checked.

Abstract: A generator monitoring system and method includes a plurality of sensors (12) disposed within a generator enclosure (18) to sense health conditions of a generator (10) housed within the enclosure. The sensors are interconnected to provide a single communication path (14) for allowing communication with the plurality of sensors. A monitoring device (16) outside the generator enclosure receives health condition information from each of the plurality of sensors via the single communication path. A sensor may be disposed within the generator enclosure to detect particulates emitted from a monitored portion (e.g., 52) of the generator housed within the enclosure. A sensor may be disposed proximate a bus bar connection (130) of the generator to sense a health condition of the bus bar connection and generate corresponding health condition information provided to the monitoring device.

Abstract: A method for measuring high-energy radiation flux includes applying a positive voltage to electrodes in an ion chamber filled with a gas capable of forming charged ions by a high-energy radiation, measuring a positive ion current signal related to ion currents induced by the positive voltage, applying a negative voltage to the electrodes, measuring a negative signal related to ion currents induced by the negative voltage, and determining a magnitude of the high-energy radiation flux based on the ion current signal.

Abstract: A radiation detector, comprising a sensitive volume filled with a counter gas; an anode and a cathode each in communication with the counter gas; a voltage supply for maintaining a potential difference between the anode and the cathode, said potential difference being less than required to cause gas discharge in the counter gas. The radiation detector further comprises a photoemissive material in communication with the sensitive volume. The photoemissive material may be provided as a coating on the cathode. The radiation detector may further comprise a controllable light source for supplying photons of a known wavelength to the photoemissive material. Electrons may be emitted by the photoemissive material in response to the provision of said photons, said electrons causing avalanche breakdown of the counter gas, indicating satisfactory operation of the radiation detector.

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 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 dosimeter based on a gas electron multiplier and method of use thereof for measurement of doses of therapeutic radiation to which a tissue-phantom is exposed. Subsequent to the in-phantom measurement and verification of radiation beam delivery, radiation can be effectively delivered to a human target organ, based on the verification of radiation quantities to which the phantom was exposed. Use of a gas electron multiplier-based dosimeter facilitates precise and accurate verification of the radiation dose within a phantom by taking measurements in real time, with no need for subsequent film processing.

Abstract: A sensor having a light detector with a small gap between the cathode and anode to enable a high pressure cavity resulting in a long lifetime of the detector due to insignificant sputtering from the cathode and subsequent minimal burying of the noble gas in the cavity. The detector may be made with MEMS technology and its techniques. The sensor may contain an array of light detectors. Some of the detectors may be UV detectors.

Abstract: An apparatus for injecting plasma in the atmosphere is provided, including a plurality of dielectric panels (13a, 13b, 13c), and 13d, which are disposed in parallel at predetermined intervals, a gas supply portion (14), to which the dielectric panels (13a, 13b, 13c, and 13d) are fixed and which supplies a gas to spaces between the dielectric panels (13a and 13b), between the dielectric panels (13b and 13c), and between the dielectric panels (13c and 13d), power electrodes (15a, 15b, and 15c), which are linearly installed near the gas supply portion (14) and between the dielectric panels (13a and 13b, between the dielectric panels 13b and 13c, and between the dielectric panels 13c and 13d), respectively, ground electrodes (16a, 16b, 16c, and 16d), which are formed in the ends of the dielectric panels (13a, 13b, 13c, and 13d), respectively, and a high frequency generator (17), which applies high frequency power to the power electrodes (15a, 15b, and 15c) and the ground electrodes (16a, 16b, 16c, and 16d).

Abstract: The instant invention is a modular radiation beam analyzer for measuring the distribution and intensity of radiation produced by a radiation source. More specifically, the instant invention is a modular radiation scanning device that includes up to three modules. By selecting and assembling a predetermined number of modules a radiation detector may be manipulated through up to three axes for radiation beam scans as well as direct Tissue Maximum Ratio (TMR) and/or Tissue Phantom Ratio (TPR) scans.

Abstract: An instrument for checking quality of therapeutic x-ray and electron radiation provides modes optimized for both electrons and for photons obtained by physically flipping the unit to interpose the necessary build-up material between the radiation beam and contained detectors. The invention provides an improved method of constructing ionization detectors for improved energy discrimination using such detectors and wire-free operation.

Abstract: The invention relates to a method and apparatus for determining the intensity distribution of a radiation field. In the method, the ionization caused by the radiation field is detected by parallel ionization detector planes arranged in an ionization chamber, two of which planes are formed of series of wires determining the position of an ionization event in the X and Y directions, which detector planes provide the X and Y co-ordinates X1, Y1 of the ionization event. The ionization event is created by photonuclear reaction products arising from the radiation.

Abstract: Microfabricated, gas-filled radiation detector assemblies, methods of making and using same and interface circuit for use therewith are provided. The assembly includes a micromachined radiation detector including a set of spaced-apart electrodes and an ionization gas between the electrodes. A housing has a chamber for housing the detector including the gas. The housing of the assembly also includes a window which allows passage of charged particles therethrough to ionize the gas to create electrons which, in turn, create an electron cascade in the gas between the electrodes when the set of electrodes is biased.

Abstract: A method of measuring the activity of a radioisotope (3) placed in an ionisation chamber (1) consists in:—determining the energy spectrum of the radiation emitted by the radioisotope;—automatically comparing the energy spectrum with a set of pre-recorded or pre-programmed radioisotope energy spectra in such a way as to identify the radioisotope present;—subsequently, automatically directing the calibration coefficient corresponding to the radioisotope present to the electronic measuring elements in order to obtain the appropriate activity measurement. The invention provides a totally automatic activity measurement. Moreover, the invention also relates to an activity meter with radioisotope recognition which is used to obtain an automatic activity measurement. The device employs one or more scintillation—or semi-conductor-type radiation detectors (10) for determining the energy spectrum of the radioisotope present.