Abstract: The particle sensor device comprises a substrate, a photodetector, a dielectric on or above the substrate, a source of electromagnetic radiation, and a through-substrate via in the substrate. The through-substrate via is exposed to the environment, in particular to ambient air. A waveguide is arranged in or above the dielectric so that the electromagnetic radiation emitted by the source of electromagnetic radiation is coupled into a portion of the waveguide. A further portion of the waveguide is opposite the photodetector, so that said portions of the waveguide are on different sides of the through-substrate via, and the waveguide traverses the through-substrate via.

Abstract: A method of measuring an environmental contaminant includes the steps of dividing a target environment into a plurality of spaces, placing a monitor in each space, uploading device data from each monitor, and processing the device data to determine a level of environmental contamination within each space. Each monitor is configured to measure a level of an environmental contaminant within the space for a sample period. A radon monitor includes a radon sensor configured to detect radon decay events, an environmental sensor configured to measure an ambient condition of air surrounding the radon sensor, a processor configured to record device data including a count of a number of radon decay events and the ambient conditions, and a communication means for transmitting the device data. A system includes a plurality of monitors, a receiving device for receive device data from each monitor, and a cloud computer to process the device data.

Abstract: Curved, flexible arrays of radiation detectors are formed by using standard silicon semiconductor processing materials and techniques and additional functionalization through integration of conversion and shielding materials. The resulting flexible arrays can be handled, integrated, further functionalized and deployed for a wide variety of applications where conventional sensors do not provide the desired functionality, form factors and/or reliability. The arrays can be stacked and include multiple types and thicknesses of conversion layers, enabling the detector to simultaneously detect multiple radiation types, and perform complex, simultaneous functions such as energy discrimination, spectroscopy, directionality detection, and particle trajectory tracking of incident radiation.

Abstract: Boron nitride nanotubes (BNNTs) with 10B combined with a scintillation gas can serve as the basis for detecting thermal neutrons by detecting light from the decay products of the thermal neutron's absorption on the 10B atoms in the BNNT Material as the resultant decay products pass through the scintillating gas. BNNTs with 11B can be utilized as a scaffold for 238U and combined with a scintillation gas as the basis for detecting fast neutrons via detecting light from the fission decay products passing through the scintillating gas. Both technologies provide high spatial and temporal resolution for the detection of thermal neutrons and fast neutrons respectively.

Abstract: Some embodiments include an imaging system. The image sensor array includes multiple image sensor sheets configured in an array grid. Each image sensor sheet of the multiple image sensor sheets can include a flexible substrate layer, and the flexible substrate layer can include a first flexible substrate side and a second flexible substrate side opposite the first flexible substrate side. Meanwhile, each image sensor sheet of the multiple sensor sheets can include multiple image sensors over the first flexible substrate side, the multiple image sensors can include multiple flat panel image detectors configured in a sheet grid, and the image sensor array can include an approximately constant pixel pitch. Other embodiments of related systems and methods are also disclosed.

Abstract: A device for detecting alpha-particles, like those emanating from radon. The device includes an electronic circuit (100) having a detection/conversion cell (102) with a forward biased diode (D) with its n-type layer grounded and the input of which is electrically connected to the p-type layer of the diode (D). The cell is designed to recover the charge emitted by the diode (D) and to convert this charge into a representative voltage constituting a dosage signal. The device further includes a comparison circuit (160) designed to compare the level of the dosage signal with a threshold level, and a control circuit (170) to control a protection device in response to the level of the voltage (V) exceeding the threshold value.

Abstract: A system for assaying a radionuclide includes a liquid scintillation detector, an analyzer connected to the liquid scintillation detector, and a delay circuit connected to the analyzer. A gamma detector and a multi-channel analyzer are connected to the delay circuit and the gamma detector. The multi-channel analyzer produces a signal reflective of the radionuclide in the sample. A method for assaying a radionuclide includes selecting a sample, detecting alpha or beta emissions from the sample with a liquid scintillation detector, producing a first signal reflective of the alpha or beta emissions, and delaying the first signal a predetermined time. The method further includes detecting gamma emissions from the sample, producing a second signal reflective of the gamma emissions, and combining the delayed first signal with the second signal to produce a third signal reflective of the radionuclide.

Abstract: Various embodiments of the present invention provide a method of detecting inaccessible radiation sources by measuring corresponding ions and excited molecules created by radiation, using LIDAR technology. The LIDAR system of the present invention employs a pulsed laser transmitter, a telescope receiver, and associated control and acquisition systems. Light propagates out from the laser transmitted and is directed into the volume surrounding the radioactive source, or the “ion cloud.” The ion cloud absorbs the transmitted light, which induces the non-fluorescing ions to fluoresce. Light from the ion cloud is then backscattered and the telescope receiver subsequently collects the photons from the backscattered light. The intensity of the fluorescence (determined by the photon count) is measured, which provides an indication of the number density of the ionized atoms. Algorithms can then be used to relate the measured ionization rates to the source activity.

Abstract: A flux detection apparatus can include a radioactive sample having a decay rate capable of changing in response to interaction with a first particle or a field, and a detector associated with the radioactive sample. The detector is responsive to a second particle or radiation formed by decay of the radioactive sample. The rate of decay of the radioactive sample can be correlated to flux of the first particle or the field. Detection of the first particle or the field can provide an early warning for an impending solar event.

Abstract: This generator is equipped with a first alpha particle detector (32) for monitoring the neutrons which are emitted within a first solid angle. According to the invention it is in addition equipped with at least one second alpha particle detector (52) for monitoring the neutrons which are emitted within a second solid angle which is different from the first solid angle. The system allows an object (2) that is placed in the first solid angle to be analysed by means of one or more gamma radiation detectors (34) that are placed in the second solid angle.

Abstract: A light emitting film is transferred to a light emitting plate serving as a transfer destination member, by a transfer method. The light emitting plate contains a first scintillator material for detecting ? ray. The light emitting film includes a protective layer, a light tight layer and a light emitting layer. The light emitting layer contains an adhesive material, and a second scintillator material added thereto for detecting ? ray. The light emitting film may be directly formed on a surface of a transparent member, a light receiving surface of a photomultiplier tube or the like by a transfer method. The light tight layer and the light emitting layer are arranged between the protective layer and the transfer destination member, and thus the light tight layer and the light emitting layer are protected physically.

Abstract: A flux detection apparatus can include a radioactive sample having a decay rate capable of changing in response to interaction with a first particle or a field, and a detector associated with the radioactive sample. The detector is responsive to a second particle or radiation formed by decay of the radioactive sample. The rate of decay of the radioactive sample can be correlated to flux of the first particle or the field. Detection of the first particle or the field can provide an early warning for an impending solar event.

Abstract: A system for in situ nuclear measurement of alpha radiation of an effluent and a related method. The system includes: M diamond semiconductor detectors obtained by chemical vapour deposition, or silicon semiconductor detectors covered with a diamond layer, as alpha radiation detectors, configured to be immersed in the effluent, and to measure alpha radiation emitted by the effluent, M is an integer greater than or equal to 1; P measuring channels connected to the M alpha radiation detectors, P is an integer greater than or equal to 1 and less than or equal to M, each of the P measuring channels configured to provide a value or a sum of alpha activity values from the M alpha radiation detectors to which they are connected; and, if P is greater than 1, a mechanism for adding together results from the P measuring channels.

Abstract: The invention relates to a device (1) for detecting the emission of a target particle (6) at an emission wavelength, said device comprising: a photo-detector (2, 2A, 2B) comprising a sensitive detection surface having a high optical index; wherein said target particle (6) can be positioned in the vicinity of said sensitive surface in an analysis medium (13) having a low optical index; said device being characterized in that it further comprises: a mask (3) covering said sensitive surface, said mask including at least one area (4) opaque at said emission wavelength and at least one hole (5), said hole being capable of receiving the target particle; and in that the mask includes at least one interface; 7 said device further comprising at least one groove (10, 10A, 10B) provided at said interface, each of said at least one groove surrounding each of said at least one hole.

Abstract: A device for detecting alpha-particles, like those emanating from radon. The device includes an electronic circuit (100) having a detection/conversion cell (102) with a forward-biased diode (D) with its n-type layer grounded and the input of which is electrically connected to the p-type layer of the diode (D). The cell is designed to recover the charge emitted by the diode (D) and to convert this charge into a representative voltage constituting a dosage signal. The device further includes a comparison circuit (160) designed to compare the level of the dosage signal with a threshold level, and a control circuit (170) to control a protection device in response to the level of the voltage (V) exceeding the threshold value.

Abstract: An imaging apparatus including a flow passage 51 formed inside a base substrate 5, an active matrix substrate 3 disposed relative to a surface of the base substrate 5, an amplifier circuit connected to the active matrix substrate, and a temperature-control heat transfer medium circulated through the flow passage 51 to remove heat generated in the amplifier circuit 4 and suppress a temperature change in a semiconductor layer 2.

Abstract: A radiation detector of the ?E-E type is proposed.

Abstract: A radon monitor includes a housing defining a housing cavity and having an opening in an exterior wall that is in fluid communication with the housing cavity to allow air to diffuse into and out of the housing cavity. The monitor also includes input and output units and a circuit board that is positioned in the housing cavity and supported by the housing. A passive, non-electrically powered sampling chamber defines a chamber cavity and is coupled to the circuit board. The circuit board defines a plurality of apertures that allow air to diffuse between the housing cavity and the chamber cavity. A detector for detecting radon is supported by the circuit board and positioned in the chamber cavity.

Abstract: A system and method for detection of alpha particles generated by a test material in proximity to a light atomic weight element. The system includes a neutron detector that is configured to detect a rate of generation of neutrons produced by an (alpha, n) reaction between the test material and the light atomic weight element. There is also at least one gamma-ray detector configured to measure a rate of generation of 511 keV gamma rays produced by an annihilation reaction triggered by a positron emission from a daughter product of the light atomic weight element. A comparator is configured to compare the rate of generation of neutrons and the rate of generation of 511 keV gamma rays.

Abstract: A system for determining an amount of radiation includes a dosimeter configured to receive the amount of radiation, the dosimeter comprising a circuit having a resonant frequency, such that the resonant frequency of the circuit changes according to the amount of radiation received by the dosimeter, the dosimeter further configured to absorb RF energy at the resonant frequency of the circuit; a radio frequency (RF) transmitter configured to transmit the RF energy at the resonant frequency to the dosimeter; and a receiver configured to determine the resonant frequency of the dosimeter based on the absorbed RF energy, wherein the amount of radiation is determined based on the resonant frequency.

Abstract: The invention relates to a design structure, and more particularly, to a design structure for an alpha particle sensor in SOI technology and a circuit thereof. The structure is a silicon-on-insulator radiation detector which includes: a charge collection node; a precharge transistor that has a source from the charge collection node, a drain at Vdd, and a gate controlled by a precharge signal; an access transistor that has a source from the charge collection node, a drain connecting to a readout node, and a gate controlled by a read-out signal; and a detector pulldown transistor having a drain from the charge collection node, a source to ground, and a grounded gate.

Abstract: A radiation detector of the ?E-E type is proposed.

Abstract: This generator is equipped with a first alpha particle detector (32) for monitoring the neutrons which are emitted within a first solid angle. According to the invention it is in addition equipped with at least one second alpha particle detector (52) for monitoring the neutrons which are emitted within a second solid angle which is different from the first solid angle. The system allows an object (2) that is placed in the first solid angle to be analysed by means of one or more gamma radiation detectors (34) that are placed in the second solid angle.

Abstract: A radiation-detecting probe instrument has a forward working portion housing a radiation detector and a rearward user directed portion, and is in communication with a control assembly for processing and outputting signals received from the radiation detector correlative to a located radionuclide source emitting energy above about 80 KeV. The disclosed probe instrument forward portion has an annular housing having a radiation transparent tip. The radiation detector is disposed behind the radiation transparent tip. A K alpha radiation emitting wafer (e.g., Pb) wafer is disposed between the radiation transparent tip and the radiation detector. A radiation resistant (e.g., W) shield is disposed between the annular housing and the radiation detector and the Pb wafer. Radiation emitted from the radionuclide source strikes the Pb wafer causing the Pb wafer to emit K alpha radiation, which strikes the radiation detector for generating signals for communication the said control assembly.

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 solid-state detector for detection of neutron and alpha particles detector and methods for manufacturing and use thereof are described. The detector has an active region formed of a polycrystalline semiconductor compound comprising a particulate semiconductor material sensitive to neutron and alpha particles radiation imbedded in a binder. The particulate semiconductor material contains at least one element sensitive to neutron and alpha particles radiation, selected from a group including 10Boron, 6Lithium, 113Cadmium, 157Gadolinium and 199Mercury. The semiconductor compound is sandwiched between an electrode assembly configured to detect the neutron and alpha particles interacting with the bulk of the active region. The binder can be either an organic polymer binder or inorganic binder. The organic polymer binder comprises at least one polymer that can be selected from the group comprising polystyrene, polypropylene, Humiseal™ and Nylon-6.

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: The invention relates to a method of detecting alpha particles in SOI technology and a circuit thereof. The structure is a silicon-on-insulator radiation detector which includes: a charge collection node; a precharge transistor that has a source from the charge collection node, a drain at Vdd, and a gate controlled by a precharge signal; an access transistor that has a source from the charge collection node, a drain connecting to a readout node, and a gate controlled by a read-out signal; and a detector pulldown transistor having a drain from the charge collection node, a source to ground, and a grounded gate.

Abstract: Processing circuitry is provided for a high voltage operated radiation detector. An event detector utilizes a comparator configured to produce an event signal based on a leading edge threshold value. A preferred event detector does not produce another event signal until a trailing edge threshold value is satisfied. The event signal can be utilized for counting the number of particle hits and also for controlling data collection operation for a peak detect circuit and timer. The leading edge threshold value is programmable such that it can be reprogrammed by a remote computer. A digital high voltage control is preferably operable to monitor and adjust high voltage for the detector.

Abstract: A flux detection apparatus can include a radioactive sample having a decay rate capable of changing in response to interaction with a first particle or a field, and a detector associated with the radioactive sample. The detector is responsive to a second particle or radiation formed by decay of the radioactive sample. The rate of decay of the radioactive sample can be correlated to flux of the first particle or the field. Detection of the first particle or the field can provide an early warning for an impending solar event.

Abstract: A cosmic ray detector includes a cantilever with a first tip. The detector also includes a second tip and circuitry to provide a signal indicative of a distance between the first and second tips being such as would be caused by a cosmic ray interaction event.

Abstract: A method and detector for detecting particle emissions from a test sample includes positioning a detector over the test sample, wherein the detector includes a plurality of detection units, wherein each detection unit includes a first silicon detector and a barrier layer removably disposed over the first silicon detector. The method includes generating a first current signal in the silicon detector in response to receiving a first particle emitted from an atom of the test sample by the silicon detector of the first detection unit, and responsive to a recoiling daughter nuclide of the atom striking the barrier layer of the first detection unit, the recoiling daughter nuclide resulting from emission of the first particle from the atom, absorbing the recoiling daughter nuclide by the barrier layer of the first detection unit.

Abstract: A radiation image detector including a charge generation layer, and a detection layer including: many pixels, each having a collection electrode for collecting charges generated in the charge generation layer, a storage capacitor for storing charges collected by the collection electrode, and a TFT switch for reading out charges from the storage capacitor; many scanning lines; and many data lines. Each storage capacitor is formed between a storage capacitor electrode connected to the drain electrode of a TFT switch and the scanning line connected to a TFT switch adjacent to the TFT switch to which the drain electrode belongs, an array of the TFT switches is divided into upper and lower halves, each data line is divided into upper and lower halves, and a dummy wire is provided at the division boundary for forming a storage capacitor of a pixel disposed at the division boundary section.

Abstract: Some embodiments include methods for fabricating an alpha particle emitter and detector associated with an integrated circuit chip. Some embodiments include an integrated circuit chip comprising an alpha particle emitter and detector supported by a semiconductor substrate. Some embodiments include an apparatus for obtaining backscatter data from a sample utilizing an alpha particle emission and detection system supported by a semiconductor substrate. Some embodiments include methods of backscatter analysis utilizing a semiconductor substrate containing an alpha particle emitter and an alpha particle sensor.

Abstract: Input circuitry is provided for a high voltage operated radiation detector to receive pulses from the detector having a rise time in the range of from about one nanosecond to about ten nanoseconds. An integrator circuit, which utilizes current feedback, receives the incoming charge from the radiation detector and creates voltage by integrating across a small capacitor. The integrator utilizes an amplifier which closely follows the voltage across the capacitor to produce an integrator output pulse with a peak value which may be used to determine the energy which produced the pulse. The pulse width of the output is stretched to approximately 50 to 300 nanoseconds for use by subsequent circuits which may then use amplifiers with lower slew rates.

Abstract: A ZnS (Ag) scintillation detector comprises a ZnS (Ag) scintillators layer 22 which is excited by incident ?-rays and emits a scintillator light, a photomultiplier tube 16 which converts the scintillator light into an electric pulse signal, and a counting rate meter 34 which counts the obtained pulse signal. The scintillator layer has a thickness which is not less than a range of ?-rays from ?-ray emitting nuclides (natural radioactive nuclides) to be separated, which enables energy absorption of ?-rays from the ?-ray emitting nuclides to be separated to entirely occur in the scintillator layer, and which enables light shielding of the scintillator light generated in the scintillator layer by the scintillator layer itself to be neglected. A pulse height discrimination circuit 32 is further provided in a preceding stage of the counting rate meter. Thereby, the effect of the natural radioactive nuclides can be reduced and the contamination control can be efficiently and smoothly performed.

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: An atomic particle detection assembly includes at least one atomic particle detector positioned within a first chamber having a first operating pressure. The assembly also includes at least one junction apparatus coupled to the at least one atomic particle detector. The at least one junction apparatus includes at least one wall that at least partially defines a second chamber having a second operating pressure. The second pressure is greater than the first pressure and the at least one junction apparatus facilitates maintaining a predetermined pressure difference between the first chamber and the second chamber.

Abstract: An atomic particle detection assembly includes at least one atomic particle detector positioned within a first chamber having a first operating pressure. The assembly also includes at least one junction apparatus coupled to the at least one atomic particle detector. The at least one junction apparatus includes at least one wall that at least partially defines a second chamber having a second operating pressure. The second pressure is greater than the first pressure and the at least one junction apparatus facilitates maintaining a predetermined pressure difference between the first chamber and the second chamber.

Abstract: The Grunn equation: Depth = 0.046 ? ? ( V acc ) n ? is modified to accurately predict depth of electron beam penetration into a target material. A two-layer stack is formed comprising a thickness of the target material overlying a detection material exhibiting greater sensitivity to the electron beam than the target material. The target material is exposed to electron beam radiation of different energies, with the threshold energy resulting in a changed physical property of the detection material below a predetermined value marking a penetration depth corresponding to the target material thickness. Utilizing the threshold energy (Vacc), the target material thickness (Depth), and the known target material density (?), the numerical power “n” of the Grunn equation is calculated to fit experimental results. So modified, the Grunn equation accurately predicts the depth of penetration of electron beams of varying energies into the target material.

Abstract: A radiation detector is described which includes first circuitry having at least one operational parameter associated therewith which is operable to change in response to radiation exposure. Second circuitry is operable to detect a change in the at least one operational parameter based on a predetermined relation between the at least one operational parameter and at least one type of radiation. The second circuitry is also operable to encode detection information representative of the radiation exposure in response thereto.

Abstract: A method of simply and quickly determining ?-ray releasing nuclides having long half-life without carrying out a chemical separation is provided. By inputting a data of pulses incident to an ?-ray detector in a computer, obtaining time distribution of the incident pulses by using a very short time measuring timer and plotting, and fitting the linear originated in a random event corresponding to the background and the non-linear originated in the correlated events of parent nuclides-progenies by using the least squares method, the whole generating probability P (t) from the parent nuclide to the progeny thereof is obtained. By subtracting the random events portion from the P(t), the correlated events portion is extracted. The radioactivity per unit can be obtained by dividing the extracted correlated events portion by the measured time, the amount of the supplied sample and the counting efficiency.

Abstract: An ?-ray measuring apparatus is provided for accurately analyzing the energy of a trace of ?-rays emitted from a sample in a short time using semiconductor detectors which excel in energy resolution. The ?-ray measuring apparatus comprises an ?-ray detector including a plurality of semiconductor detectors, an adder for adding output signals from the respective semiconductor detectors, an anticoincidence counter for anticoincidently counting the output signals from the respective semiconductor detectors, and a peak analyzer for analyzing an energy distribution of the ?-rays based on an addition of the output signals from the semiconductor detectors which are not anticoincidently counted. Since the output signals from the plurality of semiconductor detectors are added to increase the area of a sample under measurement and also remove background noise, the ?-ray measuring apparatus can more accurately analyze the energy of the ?-rays while reducing a measuring time.

Abstract: A low energy charged particle detector having a diode with a first layer and a top layer physically coupled to the first layer. The intersection between the first layer and the top layer defines a junction. The top layer is composed of a two-dimensional material such as a chalcogen-based material, providing an electrically passivated exposed outer surface opposite to the junction. The outer surface is exposed to receive low-energy charged particles from external sources. An appropriate control circuit is coupled to the diode, and operable to recognize the incidence of a particle upon the outer surface as a change in current or voltage potential.

Abstract: A detector circuit and method for detecting a silicon well voltage or current to indicate an alpha particle or cosmic ray strike of the silicon well. One significant application for the detection circuit of the present invention is for the redundancy repair latches that are used in SRAMs. The redundancy repair latches are normally written once at power-up to record failed latch data and are not normally written again. If one of the latches changes states due to an SER (Soft Error Rate-such as a strike by an alpha particle or cosmic ray) event, the repair data in the redundancy latches of the SRAM would now be incorrectly mapped. The detector circuit and method monitors the latches for the occurrence of an SER event, and responsive thereto issues a reload of the repair data to the redundancy repair latches.

Abstract: The present invention provides a flange-mounted condition monitor (30) that can be mounted to an access flange (21) on an access opening (20) on the housing (13) of a generator (10). The condition monitor (30) forms an integral part of the generator (10) and eliminates the need for complex systems of pipes and valves for transferring hydrogen samples from the generator (10) to the condition monitor (30). The flange-mounted condition monitor (30) provides greater sensitivity to overheat conditions, significantly reducing the risk of dangerous hydrogen leaks and eliminating costs associated with installing and maintaining a remote condition monitor and also reducing or eliminating the false alarms associated with water that collects in the piping of a remote condition monitor.

Abstract: A sensor arrangement and method for digital X-ray imaging. The sensor arrangement in digital X-ray imaging includes at least one sensor element which absorbs X-radiation and contains a medium, which has a relatively thin semi-conductor material structure, that converts X-ray quanta into electron-hole pairs. The surface of the element opposite to the surface receiving the X-radiation is provided with electrodes for dividing the sensor element into at least two pixel columns. Each pixel electrode is provided with detection electronics and a counter for counting the voltage or current pulses generated by the electron-hole pairs. The counters for adjacent pixel columns are connected to each other so that the counters for the pixels can be loaded from the counter for the corresponding pixel on the same row in the preceding pixel column.

Abstract: A memory array operates as an alpha particle detector. A predetermined state is stored in each memory storage location. The operating voltage of the memory array is established at a voltage where the stored values are relatively stable and not subject to change except as a result of alpha particle impingement. Impinging alpha particles are detected by the state changes they cause in the memory storage locations.

Abstract: A device for the continuous monitoring in situ of radon concentration in ambient air, and the simultaneous measurement of working level (WL) values of the radon daughters in ambient air. The device comprises an electrical field formed of two hemispherical walls facing each other with a gap therebetween allowing ambient air to diffuse through. The area between the walls is considered a “sensitive volume”. A positively-charged photodiode is disposed in communication with the sensitive volume for the detection of alpha emissions from radon or radon progeny electrically isolated within said electrical field.

Abstract: An environmental radioactivity monitor comprises a filter (12) through which air is caused to flow, and a detector (13) of radiation emitted from the particles trapped on the filter. The signals from the radiation detector are analyzed into a multiplicity of energy channels, for example with a multi-channel analyzer (22), the counts in at least two energy windows (W1, W2; W3, W4) being used to determine the shapes of the low-energy tails of the peaks of the naturally occurring radio-nuclides ThC′ and RaC′, so their effects can be eliminated. The shape of the ThC′ peak is used to predict and strip out the ThC peak, and the shape of the RaC′ peak is then used to predict and strip out the RaA peak, so all background effects are eliminated. Accurate measurements of air-borne radioactivity are hence possible with short counting times.