Abstract: Method for luminosity measuring advantageously in TLD evaluation equipment in the course of which a photomultiplier current is made proportional with light intensity and the current is measured; and sensitivity control of photomultiplier is conducted by varying its supply voltage if the current is above a given level. The change is stored. The measurement is conducted in analog or digital form. Circuit arrangement to implement the procedure has a photomultiplier tube (11), high voltage power supply and level sensor, the input of the photomultiplier tube being connected to the output of the high voltage power supply, the output of the tube being connected to the input of the level sensor. A control unit (14) is provided, whose input is connected to the output of the level sensor (12), and its output is connected to the input of the high voltage power supply.

Abstract: A TLD card reader comprising infeed and outfeed carousels for sequentially indexing cartridge holders for stacks of TLD cards to infeed and outfeed stations, and a shuttle transport for sequentially transferring TLD cards from the infeed station to a card read station and then to the outfeed station. At the read station plural photomultiplier tubes are mounted in opposition to respective hot fingers which are independently adjustable along three axes as well as independently biased for engagement with respective TL elements in a TLD card. For photomultiplier tube calibration a shuttle assembly is operable to move reference lights into the path of the shuttle transport for alignment with respective photomultiplier tubes. A light seal of star-like cross-section also is provided to seal the shuttle passageway at the read station.

Abstract: A finger ring dosimeter wherein a clasp-like support structure bent to form an open ring has a cavity formed in its apex area and a radiation detecting thermoluminescent material is disposed in the cavity and, together with the support structure is encased and sealed into a coat of plastic material. Upon heating of the ring subsequent to its exposure to radiation, the detecting material emits light from the cavity which light is measured during an evaluation process as a measure of radiation exposure of the ring and its wearer.

Abstract: A stimulable phosphor sheet comprising a support, a phosphor layer containing a stimulable phosphor and a binder, and a protective film superposed in this order, which is characterized in that at least one of the front end and the rear end of the phosphor layer along the direction to be conveyed are retracted from the corresponding end of the support, and said retracted end of the phosphor layer and support is protected by a polymer coating layer, a polymer film or a solid material.

Abstract: A radiation image reader/recorder which mainly scans an optical beam (2, 22) emitted from the optical beam generation means of a laser light source (1, 21) via a light deflector (4, 25) with a frequency less than a main scanning frequency of 1 KHz, and which sub-scans at a sub-scanning density of more than 2.5 lines/mm, reading or recording a radiation image of continuous halftones. A cover (11, 29) is provided over at least at the optical passage between the means (1, 21) and the deflector (4, 25), thereby preventing the flow of air.

Abstract: In a radiation image system wherein a stimulable phosphor carrying a radiation image stored therein is exposed to stimulating rays which cause it to emit light in proportion to the radiation energy stored, and the emitted light is detected and converted to an electric signal which is processed to reproduce a visible image, several reference gradation correction curves are created on an orthogonal system of signal level-optical density coordinates. One of the reference curves is selected and rotated around a point on the reference curve on the coordinate system, and/or parallel-shifted on the coordinate system to obtain a desired gradation correction curve.

Abstract: A stimulable phosphor is exposed to a radiation passing through an object to have a radiation image stored therein, and then exposed to stimulating rays to read out the radiation image and obtain an electric image signal. The image signal is processed under conditions suitable for the type of image recording and used to reproduce a visible image. The conditions of exposure to the radiation and the image processing conditions are adjusted by a single action of selecting the setting conditions predetermined according to the type of image recording. Also, read-out of an identification code provided on the stimulable phosphor and the exposure of the radiation are started by a single action. Or, the read-out of the identification code is conducted in response to memorizing of information on the object.

Abstract: An apparatus and method for rapidly reading thermoluminescent phosphors to determine the amount of luminescent energy stored therein. The stored luminescent energy is interpreted as a measure of the total exposure of the thermoluminescent phosphor to ionizing radiation. The thermoluminescent phosphor reading apparatus uses a laser to generate a laser beam. The laser beam power level is monitored by a laser power detector and controlled to maintain the power level nearly constant. A shutter or other laser beam interrupting means is used to control exposure of the thermoluminescent phosphor to the laser beam. The laser beam can be equalized using an optical equalizer so that the laser beam has an approximately uniform power density across the beam. The heated thermoluminescent phosphor emits a visible or otherwise detectable luminescent emission which is measured as an indication of the radiation exposure of the thermoluminescent phosphors. Also disclosed are preferred signal processing and control circuits.

Abstract: An improved thermoluminescent ionizing radiation dosimeter of solid, extremely thin construction for more accurate low energy beta dosimetry is provided, along with a method of fabricating the dosimeter. In preferred forms, the dosimeter is a composite including a backing support (which may be tissue equivalent) and a self-sustaining body of solid thermoluminescent material such as LiF having a thickness of less than about 0.25 millimeters and a volume of at least about 0.0125 mm.sup.3. In preferred fabrication procedures, an initially thick (e.g., 0.89 millimeters) TLD body is wet sanded using 600 grit or less sandpaper to a thickness of less than about 0.25 millimeters, followed by adhesively attaching the sanded body to an appropriate backing. The sanding procedure permits routine production of extremely thin (about 0.05 millimeters) TLD bodies, and moreover serves to significantly reduce non-radiation-induced thermoluminescence.

Abstract: An x-ray image storage screen for use in converting x-ray images into video pictures by the use of applied heat, such as a laser beam, has an active substance for the storage layer which is an alkaline earth-mixed halogen system having the formula BaF.sub.2 (Br, Cl):Eu:Sr, with barium fluoride (BaF.sub.2) comprising 0.6 mol, and the barium chloride (BaCl.sub.2) and the barium bromide (BaBr.sub.2) comprising the remaining 0.4 mol, preferably in equal portions, and wherein the activator europium (Eu) does not exceed 10.sup.-4 g-atom and the activator strontium (Sr) does not exceed 10.sup.-2 g-atom.

Abstract: Each of a plurality of thermoluminescent detectors (TLD's) is secured to one of a plurality of slides, which are removably mounted in a like plurality of pockets formed in a generally wallet-sized carrier to open on one edge thereof. One additional TLD is secured in a recess in one corner of the carrier to be exposed to all X-ray radiation which falls upon the carrier. Each slide is releasably secured in its associated pocket by means which prevents accidental removal of the slide from the pocket. Whenever the owner of the carrier is subjected to an X-ray examination, he or she removes from the carrier one of the slides having thereon an unused TLD, and by a means of adhesive on the back of the slide adheres the associated TLD directly in the path of the X-ray radiation to which the patient is subjected during the examination. After the examination the slide is returned to its pocket in the carrier.

Abstract: A thermoluminescence dosimeter having a very small rate of decline of sensitivity during subsequent uses after heating is disclosed. The dosimeter includes a detector crystal and a glass enclosure in which the detector crystal is located. The glass enclosure is air tight and is filled with a super dry inert fill gas. The inert fill gas is nonreactive with the detector crystal when the detector crystal is heated to thermoluminescence. The fill gas is selected from the group consisting of air, nitrogen, and argon, suitable admixed with 5 to 25 percent helium. The detector crystal consists essentially of calcium fluoride. The fill gas is preferably contained at a subatmospheric pressure in the glass enclosure.

Abstract: In a radiographic image conversion method in which a stimulating light is irradiated to a panel storing a radiation energy in the form of an image to reproduce and then to read out the image, the response speed of a stimulation and the reading speed of a radiographic image area increased by making use of (1) a phosphate type phosphor having the composition, xM.sub.3 (PO.sub.4).sub.2.NX.sub.2 :yA or M.sub.3 (PO.sub.4).sub.2 :yA, which is a highly sensitive phosphor capable of readily releasing the stored energy when a stimulating light is irradiated to the phosphor, and (2) the stimulating light having the range of the wavelengths from a visible ray of not shorter that 500 nm to an infrared ray.

Abstract: A light absorbing matter is irradiated by light ranging from ultraviolet to infrared and absorbed light energy causes the matter to be raised to an excited energy state. The excited state is then locked by maintaining the temperature of the matter at a predetermined value. Light energy thus stored can be released for utilization by changing the value of the temperature from the predetermined value.

Abstract: Three dosimeter disks of a thickness increasing towards the base piece which is to lie against the skin are used, with a covering of .beta. ray window for thermoluminescence dosimetry. In order to provide dosimetry referred to a 70 um depth of living tissue, corresponding to a weight of material per unit area of 7 mg/cm.sup.2, it is found that the thermoluminescent dosimeter (TLD) disk, which is next to the .beta. window, should have a weight per unit area in the range from 15 to 30 mg/cm.sup.2. A three-disk dosimeter should have TLD disks of increasing weight per unit area in the ratio 1:3:7 or, at any rate, the weight of the middle disk should be in the range from 30 to 90 mg/cm.sup.2, and the third disk should have a weight of at least 90 mg/cm.sup.2. TLD's are conventionally made of LiF crystals embedded in PTFE.

Abstract: In a system for reading out radiation image information recorded on a stimulable phosphor sheet which emits light upon stimulation by stimulating rays according to the recorded radiation image information, the phosphor sheet is two-dimensionally scanned by a laser beam and the light emitted therefrom is detected by a photodetector. The integrated output of the photodetector is read out for every unit of time period corresponding to a picture element of the radiation image. Position reference pulses are generated every time the relative position of the laser beam scans on the phosphor sheet by a standard amount in the main scanning direction. The integrated value of the output of the photodetector is read out every time the output is integrated for a fixed time period within each time interval between the position reference pulses.

Abstract: A thermoluminescence dosimeter reader having a heater for heating a thermoluminescence element, a light measuring circuit for measuring the intensity of the thermoluminescence emanated from the element when it is heated and a display device for displaying the reading of the dosage of radiation to which the element is exposed according to the intensity of the thermoluminescence is provided with a dosage information inputting means which outputs an electric signal having a value representing a predetermined reference dosage of radiation, a calculating means for calculating a calibration constant which is the ratio between the value of the electric signal and the output value of the light measuring circuit which is the measured value of the dosage of radiation of a reference thermoluminescence element which is exposed to the predetermined reference dosage of radiation, and a memory means for memorizing the calibration constant.

Abstract: An apparatus for erasing the fog developing in a stimulable phosphor sheet used for a radiation image recording and reproducing system in which a radiation image is once recorded in the stimulable phosphor sheet and then read out and reproduced on a recording material. The apparatus is arranged so that stimulable phosphor sheets are taken up one at a time out of their reservoir and each is loaded into a cassette used for the recording of a radiation image. It comprises a light source for erasing the fog, which is provided between the aperture of the reservoir from which the stimulable phosphor sheets are taken up and the section at which the sheets are loaded into the cassettes.

Abstract: A method and a device for sampling a radiation field emitted from an X-ray machine for determining certain operational characteristics of the machine. A cassette container is disposed at a predetermined position relative to a radiation field of the X-ray machine. The cassette container houses a removable holder containing one or more thermo-luminiscent crystals associated with a respective one or more crystal filters supported in the container. The filters have different densities from one another.

Abstract: A method of and apparatus for processing a radiation image in a radiation image recording system in which a stimulable phosphor is stimulated with a scanning stimulating ray and the light emitted from the stimulable phosphor upon stimulation by the stimulating ray is detected by a detector which gives an output to be processed and used for recording a visible image on a recording material. In the processing of the detected output, an operation represented by a formulaS'=Sorg+F(X)is conducted at every scanning point, where Sorg is the original image signal detected by the detector, Sus is an unsharp mask signal corresponding to a super-low spatial frequency, X is Sorg-Sus, and F(X) is a monotonically increasing function which satisfies the condition of F'(X.sub.1).gtoreq.F'(X.sub.2).gtoreq.0 for arbitrary values X.sub.1, X.sub.2 of X (.vertline.X.sub.1 .vertline.<.vertline.X.sub.2 .vertline.) and in which there exists at least one certain value X.sub.0 of X which satisfies the condition of F'(X.sub.

Abstract: In a radiographic image recording system in which a stimulable phosphor plate is exposed to X-rays to record a radiographic latent image therein, the stimulable phosphor plate is exposed to stimulating rays thereafter to emit light according to the stored energy of X-rays, and the emitted light is detected by a photodetector and converted to an image signal to be used for finally recording a visible image on a photosensitive film or the like, a plurality of stimulable phosphor plates are used for recording radiographic images of an object viewed from the same direction. The image signals read out from the plurality of stimulable phosphor plates are superposed to obtain an averaged image signal. The averaged image signal is then subjected to a gradation process for enhancing the contrast of the image.

Abstract: A radiation image storage panel having a fluorescent layer which comprises a binder and a stimulable phosphor dispersed therein. The fluorescent layer further contains a white powder dispersed therein in an amount of 0.01 to 1 parts by weight per one part by weight of the stimulable phosphor. The panel provides an image of high sharpness.

Abstract: A radiation image recorded in a stimulable phosphor is read out by stimulating the phosphor with a stimulating ray to have the phosphor emit light and detecting the emitted light with a photodetector. A radiation image information thus obtained is read out by a photodetector by way of a light guide member which collects the light emitted by the phosphor and guides the collected light to a photodetector. The light guide member is made of a transparent sheet having smooth surfaces for effecting total reflection. The light guide member has a linear or arcuate end to be located adjacent to a scan line of the stimulable phosphor to receive and guide the light emitted by the phosphor and an annular end to be located adjacent to the light receiving face of the photodetector. The light entering the light guide member through the flat end is guided to the annular end by repeated total reflection.

Abstract: A method and apparatus for processing a radiation image in a radiation image recording system in which a stimulable phosphor is stimulated with a scanning stimulating beam and the light emitted from the stimulable phosphor upon stimulation by the stimulating beam is detected by a detector which generates an output which is processed and used for recording a visible image on a recording material. In the processing of the detected output, an operation represented by a formulaS'=Sorg+.beta. (Sorg--Sus)is conducted, where Sorg is the original image signal detected by the detector, .beta. is an emphasis coefficient, and Sus is an unsharp mask signal corresponding to a super-low spatial frequency at every scanning point. The unsharp masking process may be performed together with a gradation process, reduction of image size, smoothing process and the like. Further, the emphasis coefficient may be varied with either the original image signal Sorg or the unsharp mask signal Sus.

Abstract: An automatic thermo-luminescence desimeter, comprising a thermo-luminescence dosimeter element which is composed of a card carrying a thermo-luminescence material and contained in an encasing member; a magazine adapted to accommodate therein a plurality of the thermo-luminescence dosimeter elements; means for transporting the magazine; card feeding means for extracting a thermo-luminescence dosimeter element from the magazine and feeding the element into a longitudinal groove formed in a housing; releasing means for releasing engagement between the card and the encasing member; means for feeding the card into a transversal groove formed in the housing; heating means for heating the thermo-luminescence material carried by the card fed to the transversal groove by irradiating with infrared rays; and photoelectric converter means for converting thermo-luminescence emitted by the thermo-luminescence material into an electric signal, whereby doses of exposed radiation of the individual theremo-luminescence dosimet

Abstract: A radiation image recorded in a stimulable phosphor is read out by stimulating the stimulable phosphor by use of stimulating rays such as visible light or infrared rays. Upon stimulated, the stimulable phosphor emits light which is detectable by a photosensor. The radiation image readout device includes a photosensor for detecting the light emitted by the phosphor, and a reflecting optical element like a mirror located between the phosphor and the photodetector for reflecting stimulating rays advancing between the phosphor and the photosensor toward the phosphor. The reflecting optical element has a very small size not to intercept the light emitted by the phosphor and detected by the photosensor as much as possible.

Abstract: A method and apparatus for processing a radiation image in a radiation image recording system in which a stimulable phosphor is stimulated with a scanning stimulating ray and the light emitted from the stimulable phosphor upon stimulation by the stimulating ray is detected by a photodetector which gives an output to be processed and used for recording a visible image on a recording medium. The radiation image of the frontal chest is gradation processed. The gradation processing is characterized in that the density between the densities of the spine and the heart of the image on the recording medium is lowered to lower the contrast of the spine and raise the contrast of the heart and the lungs.

Abstract: A process for producing a lithium borate thermoluminescent and fluorescent substance containing lithium borate as its main component which comprises heat-treating a mixture of Li.sub.2 B.sub.4 O.sub.7 powder and an activator element compound at a temperature under and neighboring the melting point of Li.sub.2 B.sub.4 O.sub.7, to provide a highly sensitive fluorescent substance which has good adherence to the substrate of a dosimeter.

Abstract: In a method of recording a radiation image by use of a stimulable phosphor in which the stimulable phosphor is first exposed to an imagewise radiation to store the energy of the radiation and then is exposed to stimulating rays to emit light in accordance with the energy stored therein, the instantaneous emission of light emitted upon exposure of the stimulable phosphor to the radiation is detected to measure the level of the energy of the radiation stored in the phosphor. The instantaneous emission is detected by a photosensor which is located behind the phosphor. The output of the photosensor is utilized to control the density and/or contrast of the final image recorded on a photographic film which is recorded by use of the light emitted by the phosphor upon stimulated.

Abstract: In a radiation image recording system in which a radiation image is once recorded in a stimulable phosphor and then read out and reproduced on a recording material, the gradation of the radiation image is processed to enhance the diagnostic efficiency and accuracy of the image. The radiation image is read out by scanning the stimulable phosphor by a stimulating ray to cause the phosphor to emit light of the amount corresponding to the radiation energy stored in the phosphor. The emitted light is detected and converted to an electric signal. The level of the electric signal is converted in such a way that the maximum level of the signal corresponding to the maximum density of the radiation image is converted to a level resulting in the optical density of 1.5 to 2.8 in the reproduced image on a recording material and the minimum level corresponding to the minimum density is converted to a level resulting in the optical density of fog density of the recording material to fog density plus 0.

Abstract: A technique of applying the thermoluminescence phenomenon to uranium prospecting. The thermoluminescence of specimens of quartz isolated from field samples is measured. The samples are then irradiated at several levels, and the thermoluminescence of the samples is measured at the various levels. This enables a determination of the natural radiation received by the samples The current radiation from the samples is measured with a dosimeter, and by using both shielded and unshielded dosimeters the type of radiation from the samples can be determined. Knowledge of the total natural radiation received by a sample and the current rate of radioactivity allows the determination of the present position of uranium or other radioactive source and its geological "migration" path.

Abstract: A phosphor for a thermoluminescent radiation dosimeter, comprising lithium tetraborate as a base material and copper as an activator. In addition to these components lithium octaborate may further be included as a base material, and silver as an activator. The phosphors according to the invention have an effective atomic number quite near to that of tissue, so that it is suitable for measuring the radiation dose absorbed by a tissue specimen. Further they exhibit emission a spectra peak at 368 m.mu. which is convenient for measuring the response of widely used photomultiplier tubes. The sensitivities to .gamma.-rays are also improved, compared to the known lithium borate phosphor.

Abstract: A temperature probe measures temperature changes within biological material while the tissue is being irradiated with microwaves. In order to measure tissue temperatures accurately a probe must be designed to function in a microwave field while causing minimum perturbation to the microwave field. This generally requires a probe being constructed of dielectric (non-metallic) material which utilizes physical phenomena which are thermally dependent yet unaffected by electromagnetic fields at the field strength and frequencies of interest. In one embodiment the structure of the probe basically includes an optical fiber bundle for conducting light both toward and away from a temperature sensitive luminescent element located at one end of the optical fiber bundle, the source for exciting the temperature sensitive element and a light responsive detection element located at the output end of the optical fiber bundle for detecting light emitted from the temperature sensitive element which is temperature dependent.

Abstract: Process for the production of a sensitive plate for an exoelectron dosimeter by producing on a support a deposit of a mixture of two compositions constituted on the one hand by a substance having traps for the electrons and able to emit exoelectrons by thermal or optical stimulation and on the other by a substance having a good ionic conductivity, wherein it comprises making a homogeneous mixture of the powders constituting the two said compositions, producing by means of a plasma arc torch a plasma jet in the vicinity of the support on which the deposit is to be made and spraying said powder mixture into the jet to obtain a deposit which adheres to the support.The exoelectron dosimeter comprises a support to which adheres a plate constituted by two substances, one of which has traps for the electrons and is able to emit exoelectrons by thermal or optical stimulation and the other has a good ionic conductivity.

Abstract: Measurements of radiation exposure below 1 mR are possible with a BeO ceramic thermoluminescent detector (TLD) by treating the TL signal in a manner that discriminates against an interferring pyroelectric incandescence (PI). This is accomplished by differentiating the signals electronically to cause the composite signal to cross the baseline. A zero-crossing detector then senses and clips the negative-going portion of the signal. The resultant signal is integrated, producing a result wherein the true TL signal is substantially greater than the PI signal.

Abstract: A method for the qualitative and quantitative analysis of asbestiform minerals, including the steps of subjecting a sample to be analyzed to the thermoluminescent analysis, annealing the sample, subjecting the sample to ionizing radiation, and subjecting the sample to a second thermoluminescent analysis. Glow curves are derived from the two thermoluminescent analyses and their shapes then compared to established glow curves of known asbestiform minerals to identify the type of asbestiform in the sample. Also, during at least one of the analyses, the thermoluminescent response for each sample is integrated during a linear heating period of the analysis in order to derive the total thermoluminescence per milligram of sample. This total is a measure of the quantity of asbestiform in the sample and may also be used to identify the source of the sample.

Abstract: In a radiation dosimeter assembly consisting of a wafer-like radiation dosimeter in combination with a mechanical support member the radiation dosimeter is secured within an aperture of the support member by disposing a protective film on either side of the dosimeter and securing the film to the support member via a high temperature adhesive or high temperature adhesive film. This assembly technique permits the annealing of the combination of the dosimeter and the support member to a temperature of about 300.degree. C. which is the typical process for "erasing" extraneous radiation dosage stored in the dosimeter prior to the use of the radiation dosimeter/support combination for radiation measurements. The capability of annealing the total combination permits stock piling of preassembled radiation dosimeter/support member combinations for extended periods of time.

Abstract: The sensitive plate of a dosimeter for the measurement of radiation by emission of exoelectrons is formed of material consisting of a mixture of a first substance containing traps for the electrons and capable of emitting exoelectrons by thermal or optical stimulation and a second substance which has good ionic conductivity and is capable of producing material having high mechanical strength.

Abstract: The heating element in a conventional radiation dosimeter reading apparatus which functions to both physically support a dosimeter as well as heat the dosimeter to a temperature of luminescence, is modified to include a dished portion, or recessed portion, having a flat bottom and sufficient dimensions to receive the radiation dosimeter and allow for the positioning of a transparent retainer, i.e., a glass plate, in contact with the dosimeter to physically retain the dosimeter in the recess to avoid deformation of the dosimeter when heated, and transmit light emanating from the dosimeter when heated.

Abstract: A method of thermoluminescent dosimetry employing infrared radiation heating of a dosimeter. An incandescent lamp is used for the source of infrared radiation. The dosimeter is provided with a infrared radiation absorbing layer connected thermally to a thermoluminescent material layer. The infrared radiation absorbing layer is irradiated with infrared radiation, so that thermoluminescent material is not directly irradiated. The lamp is initially powered whereby the dosimeter is heated by infrared radiation of such high intensity as to tend to cause a heat equilibrium in the dosimeter above the temperature where thermal radiation is generated from the dosimeter. Then the power supplied to the lamp is cut or decreased, so that the dosimeter is heated by the afterglow of the lamp. Therefore the rate of temperature rise of the dosimeter becomes quite slow in the latter half of heating process, whereby the temperature of dosimeter easily falls into the required range.

Abstract: In a method for determining the radiation received in the past by a TSC dosimeter, the dosimeter is connected to a voltage source providing a polarizing voltage across the dosimeter and to an external closed electric circuit. The initial current pulse then flowing through the dosimeter due to its capacitive properties is detected and measured and if its peak value lies within a predetermined range the actual reading-off of the radiation dose received by the dosimeter is started in that a heating of the dosimeter is initiated and the thermally stimulated currents then produced by the dosimeter in the external closed electric circuit are measured and recorded.

Abstract: Underground uranium deposits are located by placing wires of dosimeters each about 5 to 18 mg/cm.sup.2 thick underground in a grid pattern. Each dosimeter contains a phosphor which is capable of storing the energy of alpha particles. In each pair one dosimeter is shielded from alpha particles with more than 18 mg/cm.sup.2 thick opaque material but not gamma and beta rays and the other dosimeter is shielded with less than 1 mg/cm.sup.2 thick opaque material to exclude dust. After a period underground the dosimeters are heated which releases the stored energy as light. The amount of light produced from the heavily shielded dosimeter is subtracted from the amount of light produced from the thinly shielded dosimeter to give an indication of the location and quantity of uranium underground.

Abstract: An apparatus wherein a thermoluminescent type radiation dosimeter is heated and thermoluminant rays emitted from the dosimeter are measured. It is constructed in such manner that to perform the measurement a personal identification card must be inserted to the apparatus. The mark on the dosimeter and the mark on the identification card are collated, and only when they coincide with each other is the measurement performed.

Abstract: A method for measuring the dose-equivalent for exposure to an unknown and/or time varing neutron flux which comprises simultaneously exposing a plurality of neutron detecting elements of different types to a neutron flux and combining the measured responses of the various detecting elements by means of a function, whose value is an approximate measure of the dose-equivalent, which is substantially independent of the energy spectra of the flux. Also, a personnel neutron dosimeter, which is useful in carrying out the above method, comprising a plurality of various neutron detecting elements in a single housing suitable for personnel to wear while working in a radiation area.

Abstract: A readout instrument comprising a heating device such as a multi-nozzle hot air blower for individually heating a plurality of thermoluminescence dosimeter elements, a photoelectric transducer, an optical guide for efficiently condensing the luminescence ray on the photosensitive face of the transducer, and a thermal radiation shield plate with slits in the same number as the dosimeter elements to minimize errors in the readout attributable to heat radiation from heated bodies such as components of the heating device.

Abstract: A dosimetry technique for high-energy gamma radiation or X-radiation employs the Compton effect in conjunction with radiation-induced thermally activated depolarization phenomena. A dielectric material is disposed between two electrodes which are electrically short circuited to produce a dosimeter which is then exposed to the gamma or X radiation. The gamma or X-radiation impinging on the dosimeter interacts with the dielectric material directly or with the metal composing the electrode to produce Compton electrons which are emitted preferentially in the direction in which the radiation was traveling. A portion of these electrons becomes trapped in the dielectric material, consequently inducing a stable electrical polarization in the dielectric material.

Abstract: Underground uranium deposits are located by placing pairs of dosimeters each about 5 to 18 mg/cm.sup.2 thick underground in a grid pattern. Each dosimeter contains a phosphor which is capable of storing the energy of alpha particles. In each pair one dosimeter is shielded from alpha particles with more than 18 mg/cm.sup.2 thick opaque material but not gamma and beta rays and the other dosimeter is shielded with less than 1 mg/cm.sup.2 thick opaque material to exclude dust. After a period underground the dosimeters are heated which releases the stored energy as light. The amount of light produced from the heavily shielded dosimeter is subtracted from the amount of light produced from the thinly shielded dosimeter to give an indication of the location and quantity of uranium underground.

Abstract: The subject matter described is a U.V. detector of the ionization type for operation at high temperatures where it is necessary to cyclically reverse the potential applied to the sensor to prevent premature aging of the detector. In the present disclosure, the means for reversing the potential at a predetermined rate is shown as a free running oscillator multivibrator connected to switch the power supply. The novel aspect is in locking out the oscillator when U.V. is being sensed by the detector.

Abstract: A method is disclosed for the use of thulium doped calcium fluoride in the form of a thermoluminescent dosimeter to measure the amount of radiation to which the dosimeter has been exposed.A new thermoluminescent material for use in a dosimeter is also disclosed. The material consists essentially of crystalline calcium fluoride doped with less than 0.5 mole percent thulium. The material has several unique properties, and displays two well separated glow maxima which permit using a lower temperature (150.degree. C) peak as a thermometer to determine a mean ambient temperature for the dosimeter. The mean ambient temperature may then be used to correct thermoluminescent data for a high temperature (250.degree. C) peak.

Abstract: The disclosure relates to an apparatus and method for recording images on recording mediums which images correspond to high energy radiation patterns. A temporary storage medium, such as an infrared-stimulable phosphor or thermoluminescent material, is exposed to an incident pattern of high energy radiation. A time interval after exposure, a small area beam of long wave length radiation or heat scans the screen to release the stored energy as light. An appropriate sensor receives the light emitted by the screen and produces electrical energy in accordance with the light received. The information carried by the electrical energy is transformed into a recorded image by scanning an information storage medium with a light beam which is intensity modulated in accordance with the electrical energy. Although the invention can be used at any reproduction ratio, it is particularly usable in recording images representative of large format high energy patterns onto microfilm.