Abstract: A method and apparatus for determining radiation absorbed dose using optically stimulated luminescence (OSL) in dental enamel. The invention is based on the determination that OSL can be induced in dental enamel and can be used for determining absorbed radiation dose, for example during unmonitored x-rays, or accidental exposures to ionizing radiation. In particular, it has been discovered that there is a dose dependent OSL in dental enamel. The present invention makes possible a non-invasive, sensitive, reliable and portable method and apparatus for in vivo human radiation dosimetry.

Abstract: A method for measuring the fixed contamination level in a confined area such as small diameter pipe. The method measures the accumulated detection response over a given area and prescribed time period. To obtain the measurement a plurality of sensors are connected in tandem to form a flexible detector string and remotely positioned within the area to be monitored. The measurement is correlated to a standard obtained by using a known source in a simulated mockup environment. In one embodiment a passive monitor such as a Thermo-Luminescence Dosimeter is employed as the sensor.

Abstract: A dose distribution analyzer (20) and methods for providing a radiation dose map indicating energy of a spacially variable radiation pattern beamed onto a dose map radiation dosimeter (10). The radiation dosimeter (10) is exposed to a proposed spacially variable radiation pattern such as used in a phantom patient for patient radiation dose treatment verification. The dosimeter (10) is subsequently analyzed by the dose distribution analyzer (20). Such analyzer includes a phosphor stimulator (53), an image forming subsystem (38), and an image sensor (37). A dosimeter holder (32) holds the dosimeter near the phosphor stimulator (53). A system controller (22) is connected to receive image data from the image sensor (37) while the dosimeter (10) is stimulated. The controller (22) utilizes the image data to derive a radiation dose map which indicates the distribution of radiation in the spacially variable radiation pattern which strikes the dosimeter (10).

Abstract: Versatile method and device of thermoluminescence analysis are provided. Such a method and device can be applied to: exploration of petroleum, natural gas and minerals; forensic examination of objects; environmental monitoring; and production quality control. The device includes: a heating element; an optical readout system; and a rotating disk with openings for passage of light emitted by a heated sample. The device further includes a reference light source for controlling the optical readout system, and a computer system for controlling the operation of said device and for data storage, retrieval and processing.

Abstract: Radiation is detected using a light transparent thermoluminescent dosimeter that comprises a nanocrystalline phosphor dispersed in a light transparent glassy matrix, such as Vycor glass. The dosimeter is placed in an environment in which radiation is present for a period of time, removed from the environment and then heated to emit light, the intensity of which is indicative of the radiation dose. The method of the invention is useful for detecting and recording the dosage of both UV and ionizing radiation. In one embodiment in which the dosimeter is in the form of a flat plate. Ambient .alpha. or .beta. radiation populates traps and, upon heating of the flat dosimeter, the emitted light is guided to the edges of the dosimeter by total internal reflection, where it is detected and recorded.

Abstract: A thermoluminescent radiation dosimeter system for the remote monitoring of adiation sources. The system includes a radiation-sensitive thermoluminescent dosimeter which utilizes a new, semiconductor-doped glass material disposed at a remote location for storing energy from ionizing radiation when exposed thereto and for releasing the stored energy in the form of thermoluminescence light at a first wavelength when stimulated by exposure to light energy at a predetermined stimulating second wavelength.

Abstract: A luminescent glass includes nanocrystalline semiconductor particles, such as ZnS nanocrystals, and an activator, such as copper, for the particles. The glass is made by depositing the nanocrystalline semiconductor particles and the activator within a porous glass matrix, such as 7930 Vycor.TM. and then thermally activating the glass. The porous glass matrix may be at least partially consolidated or may be allowed to remain porous. The nanometer particle size permits the luminescent glasses of the present invention to be transparent to its luminescent emissions.

Abstract: A dosimetry system and method characterized by use a plurality of radiation sensitive elements to monitor exposure to a radiation field composed of one or more types of radiation at one or more different energies; reading the radiation sensitive elements in a reader after irradiation by the radiation field to obtain element outputs; and supplying the element outputs to a trained neural network computer apparatus wherein the element outputs are analyzed to provide an output indicative of the radiation field.

Abstract: A radiation monitoring system and method characterized by the use of paired active and passive radiation detectors to monitor exposure to a radiation field. The active detector provides an output representative of radiation exposure on a real time basis while the passive detector is readable on a delayed basis after exposure to radiation for a period of time to provide an output representative of radiation exposure over said period of time. Respective readers are provided for extracting the radiation exposure information from the detectors, as is a processor which determines a quantity of radiation exposure from the radiation information extracted from the detectors. The processor corrects radiation exposure data derived from one of the detectors using radiation exposure data derived from the other of the detectors.

Abstract: A process and apparatus for revealing manufacturing defects in testpieces, such as printed circuit boards, by passing through high-intensity attenuated x-rays (above 150 Kilo-Volts) to reusable photo plates for revealing defects in the testpieces. The x-rays are angled from 35 to 50 degrees for generating images of defects within thick multilayered printed circuit boards. During exposure, a thin lead sheet is placed between the testpiece and a phosphor photographic plate on a side of the testpeice opposite the x-ray gun. The lead sheet uniformly attenuates the high-energy x-rays to the captured image before they reach the phosphor plate to avoid damage to the photographic reuse of the plate and prevent over-exposure without loss of image contrast in the phosphor photograph. The exposed phosphor plate is excited with a low energy monochromatic radiation to visually activate the latent x-ray image in the exposed plate.

Abstract: A dosimeter product that simplifies the process of dosimetry in medical diagnosis, therapy and other fields where high precision is needed. The dosimeter product is obtained by a unique training method which stabilizes the sensitivity of the dosimeter. Stability in sensitivity is established by a combination of high temperature cyclical annealing and low temperature furnace annealing. After the sensitivity of the dosimeters is stabilized, the dosimeters are then calibrated by generating for every dosimeter within a group element correction coefficients (ECCs) that compensate for the differences in sensitivity among the group of the dosimeters, bringing the sensitivity of each dosimeter to the sensitivity of the mean of the population. The result is a group of precalibrated dosimeters with stable sensitivity that are ready to use with established correction factors for individual TL response differences.

Abstract: Apparatus and method for electronically screening abnormal glow curves of thermoluminescenct materials such as LiF:Mg,Ti in routine dosimetry, wherein glow curves with abnormal patterns are identified by examining a few key features from which information about background and thermoluminescent (TL) signals can be extracted. By analyzing the records of quality control (QC) cards that are in the same group as field cards, dosimeter- and reader-dictated parameters, such as the peak location, are automatically determined, thus eliminating the need for any prior knowledge of those conditions required for reference determination. The apparatus and method are applicable to dose levels down to at least 50 .mu.Sv.

Abstract: Dose of radiation to which a body of crystalline material has been exposed is measured by exposing the body to optical radiation at a first wavelength, which is greater than about 540 nm, and measuring optical energy emitted from the body by luminescence at a second wavelength, which is longer than the first wavelength. Reduced background is accomplished by more thorough annealing and enhanced radiation induced luminescence is obtained by treating the crystalline material to coalesce primary damage centers into secondary damage centers.

Abstract: A dosimeter for use in mixed radiation fields is disclosed. The dosimeter consisting of a single element may be used in a photon-neutron field if the energies of the photons and neutrons are known. In a mixed photon-neutron-beta radiation field of unknown energies, a detector having four elements is sufficient to provide an estimate of the exposure. The dosimeter makes use of the high temperature readout from a 6Li doped LiF thermoluminescent detector to provide an estimate of both the neutron and photon exposures.

Abstract: In image signal storing method and apparatus, a continuous tone image signal representing a continuous tone image and a binary image signal representing a binary image, which carries information giving specifics about the continuous tone image, are obtained. A redundancy imparting process is carried out on the binary image signal in accordance with irreversible signal compression processing such that the information represented by the binary image signal may not be reduced when the irreversible signal compression processing is carried out. Thereafter part of the continuous tone image signal, which part corresponds to part of the region in the continuous tone image, is replaced by the binary image signal, which has been obtained from the redundancy imparting process. The irreversible signal compression processing is then carried out on an image signal, which has been obtained from the replacement. An image signal, which has been obtained from the irreversible signal compression processing, is then stored.

Abstract: The method and apparatus of the present invention relate to cryogenically cooling a thermoluminescent material, exposing it to a low level of radiation (less than about 1 R) while it is at the cooled temperature, warming the thermoluminescent material to "room temperature", and counting the photons emitted during heating. Sufficient sensitivity is achieved without exposing the thermoluminescent material to ultraviolet light thereby simplifying the measurements.

Abstract: System and method for extremity dosimetry, that emables the maintenance of a chain of custody from dosimeter issuance to dosimeter read and further through multiple reuses of the dosimeter, are uniquely characterized by a reusable extremity dosimeter comprising a solid thermoluminescent (TL) body affixed as by bonding to a non-luminescent substrate that has integrally associated therewith indicia embodying a machine readable identification code. A preferred holder for the extremity dosimeter comprises a generally flat and flexible pouch that may be disposable, the dosimeter pouch including at least one pocket for containing the extremity dosimeter. Provision is made for attaching the dosimeter pouch to the body of a user at a specified extremity location such as a finger, wrist, toe, ankle, elbow, knee, forehead, etc. Also disclosed is a carrier for enabling the reading of the extremity dosimeters in TLD readers designed to read TLD cards containing multiple TL elements.

Abstract: A TLD dosimeter and method of making same, characterized by assembling a solid body of TL material on a non-luminescent substrate with a non-luminescent liquid adhesive interposed between juxtaposed parallel surfaces of the TL body and substrate, and heating the assembly to cure the liquid adhesive thereby to bond the TL body to the substrate. The liquid adhesive is a polyimide. For bonding the solid body to a film substrate such as an aromatic polyimide film, the TL body and film substrate are pressed together during heating and the heating step preferably involves baking the assembly at a high temperature.

Abstract: The amount of ionizing radiation to which a thermoluminescent material has been exposed is determined by first cooling the thermoluminescent material and then optically stimulating the thermoluminescent material by exposure to light. Visible light emitted by the thermoluminescent material as it is allowed to warm up to room temperature is detected and counted. The thermoluminescent material may be annealed by exposure to ultraviolet light.

Abstract: Disclosed is a laser dosimeter reading apparatus having a controllable optical laser converter for providing multiple stimulating laser beams. The converter laser dosimeter reader can be used to stimulate or otherwise treat dosimeter elements to perform two or more distinct processes on a particular dosimeter element. Additionally, the convertible dosimeter reader can be used to read multiple different types of dosimeter elements contained on a single dosimeter badge, thereby allowing a badge to be read in a multi-stage reading operation in a single dosimeter reader which is preferably automated. The optical laser converter includes a converter block assembly which defines multiple optical pathways therethrough. The convert block assembly is movable between different positions to align the different optical pathways with an incoming laser beam.

Abstract: Disclosed is a radiation dosimeter reading apparatus designed to disassemble, reposition, read, and reasemble radiation dosimeter badges. The dosimeter reading apparatus includes a dosimeter badge chuck assembly which engages a dosimeter badge in an infeed dosimeter badge holder. The chuck assembly engages the dosimeter badge using a set of tamper element prongs which depress a tamper ring which forms part of the dosimeter badge. The depression of the badge tamper ring releases a locking ring which also forms part of the dosimeter badge. Once the locking ring is freed, then another set of prongs on the chuck assembly are rotated to route the locking ring of the badge and thereby release a disk-shaped dosimeter badge insert. The chuck assembly is further adapted to grasp the released insert by contracting the tamper element prongs inwardly against the perphery of the disk-shaped insert to hold the inset on the chuck assembly.

Abstract: Disclosed is a laser dosimeter reading apparatus having a controllable optical laser converter for providing multiple stimulating laser beams. The convertible laser dosimeter reader can be used to stimulate or otherwise treat dosimeter elements to perform two or more distinct processes on a particular dosimeter element. Additionally, the convertible dosimeter reader can be used to read multiple different types of dosimeter elements contained on a single dosimeter badge, thereby allowing a badge to be read in a multi-stage reading operation in a single dosimeter reader which is preferably automated. The optical laser converter includes a converter block assembly which defines multiple optical pathways therethrough. The convert block assembly is movable between different positions to align the different optical pathways with an incoming laser beam.

Abstract: After an image signal made up of a series of image signal components is detected from a recording medium on which a radiation image may be recorded, a characteristic value which represents the maximum change in the value of the image signal components corresponding to positions located along each of a plurality of lines distributed over the overall region or over a partial region of the recording medium is calculated. A representative value, which is representative of a plurality of the characteristic values, is calculated. Alternatively, after the image signal is detected, the probability density function of the image signal components corresponding to the overall region or to a partial region of the recording medium is created, and a characteristic amount, which represents a specific characteristic of the probability density function is found. The representative value or the characteristic amount is compared with a predetermined value.

Abstract: M-center luminescence is used to measure radiation. An LiF crystal is excited with a 442 nm He-Cd laser because absorption measurements in LiF indicate the peak of the M-center absorption occurs at 443 nm. Laser stimulation produces an excited state of the M-center, which undergoes a very strong Stokes' shift. The peak of the M-center emission spectrum occurs at 665 nm with a half-width of 0.36 ev. Since the excitation wavelength differs significantly from the emission wavelength, measurement of the deep red emission can be done simultaneously with the excitation. The population of M-centers grows with increasing radiation damage, and therefore M-center lunimescence provides a basis for radiation dosimetry.

Abstract: The amount of ionizing radiation to which a thermoluminescent material has been exposed is determined by first cooling the thermoluminescent material to a cryogenic temperature. The thermoluminescent material is then optically stimulated by exposure to ultraviolet light. Visible light emitted by the thermoluminescent material as it is allowed to warm up to room temperature is detected and counted. The thermoluminescent material may be annealed by exposure to ultraviolet light.

Abstract: Dosimeter reading methods and apparatus particularly useful in the measurement of heavy particle radiation dose exposure, such as from neutrons, protons, and alpha particles among others. The methods include exposing a dosimeter to a radiation environment to be measured. The dosimeter is thereafter stimulated, such as by a laser beam, to cause emission discharges from the dosimeter which are variable and indicative of the amount of ionizing radiation to which the element was exposed. Dosimeter elements which experienced an ionizing event from a heavy particle have higher levels of energy stored therein and produce higher luminescent or other emissions, thus characterizing that element or sample area as an eventful sample area. The number, portion or other measure of the eventful sample areas provides a basis for determining the level of radiation exposure due to the heavy particle or other discernable type of ionizing event.

Abstract: A radiation image read-out apparatus comprises a read-out component, an image processing component, and a menu item display and selection component.

Abstract: A method of detecting, counting or otherwise measuring nuclear radiation includes the steps of exposing a diamond containing single substitutional paramagnetic nitrogen to the nuclear radiation to cause electrons or holes to be trapped at lattice imperfections within the diamond crystal structure, heating the diamond to cause it to luminesce and utilizing the luminescence as a means for the detection, counting or measurement of the nuclear radiation. The method is characterized by subjecting the diamond to a high dose of neutron or electron irradiation prior to exposing it to the nuclear radiation to be detected. This, it has been found, improves both the sensitivity of the diamond as a thermoluminescent material and linearity of the thermoluminescent response to nuclear radiation dose.

Abstract: The method and system interpretation for determining dose equivalents of a multi-element thermoluminescent dosimeter in mixed photon-beta and photon-neutron fields is described. The four TL Elements are covered by nearly tissue equivalent filters including only one metal filter which is used to provide low energy photon discrimination. In a mixed field, deep and shallow dose equivalents and the identity of the field's components are derived from the dosimeter's response in pure fields.

Abstract: Disclosed are methods and apparatus for remotely measuring radiation levels. Such are particularly useful for measuring relatively high levels or dosages of radiation being administered in radiation therapy. They are also useful for more general radiation level measurements where remote sensing from the remaining portions of the apparatus is desirable. The apparatus uses a beam generator, such as a laser beam, to provide a stimulating beam. The stimulating beam is preferably of wavelengths shorter than 6 microns, or more advantageously less than 2 microns. The stimulating beam is used to stimulate a remote luminescent sensor mounted in a probe which emits stored luminescent energy resulting from exposure of the sensor to ionizing radiation. The stimulating beam is communicated to the remote luminescent sensor via transmissive fiber which also preferably serves to return the emission from the luminescent sensor.

Abstract: A radiation image read-out apparatus comprises a preliminary read-out device, a final read-out device, an image processor, and a condition adjuster. The condition adjuster comprises an operating device for determining the read-out conditions for the final readout and/or the image processing conditions and feeding the information about them into the final read-out device and/or the image processor. From a first input device, information about a mode selected from among several modes of adjusting the read-out conditions and/or the image processing conditions is fed into the operating device. In cases where a region selecting mode is designated, an image represented by a preliminary read-out image signal is displayed.

Abstract: A small scintillation crystal has a surface which is coated with a thin layer of aluminium or cobalt. The aluminium is etched with identification markings, as by a laser.

Abstract: The present invention constitutes a system for determining the amounts of ionizing radiation to which dosimeters using thermoluminescent materials have been exposed. In accordance with this system, the thermoluminescent materials which comprise the dosimeters are first cooled by contact with a cryogenic substance such as liquified nitrogen. The thermoluminescent materials are then optically stimulated by exposure to ultraviolet light. Thereafter, the amounts of visible light emitted by the thermoluminescent materials are detected and counted as the materials are allowed to warm up to room temperature. The amounts of luminescence exhibited by the materials are related to radiation exposure and provide a sensitive measure of radiation dosage. It has been discovered that the above procedure is most effective when heavily doped thermoluminescent materials are used and that the procedure allows many useful plastic materials to now be employed in dosimeter constructions.

Abstract: A radiation image read-out apparatus comprises a preliminary read-out device, a final read-out device, an image processor, and a condition adjuster. The condition adjuster is constituted of an operating section for calculating, from a preliminary read-out image signal, read-out conditions to be used in obtaining a final read-out image signal and/or image processing conditions to be used in image processing of a final read-out image signal, and carrying out image reproduction operating processes based on the preliminary read-out image signal so as to display images which would be reproduced if the calculated read-out conditions and/or the calculated image processing conditions were used. One of the images displayed is designated, and the operating section feeds a read-out condition and/or an image processing condition, which corresponds to the designated image, into the final read-out device and/or the image processor.

Abstract: A method of determining the nature of an unspecified laser source using the optically and thermally stimulated luminescence characteristics of a single MgS phosphor doped with either Ce, Sm or Eu, Sm ions. The doped MgS phosphor is first exposed to charging radiation thereby allowing electron trapping to occur. Subsequent to the electron trapping, the phosphor is exposed to the energy of an unspecified laser source which frees the trapped electrons. The freed electrons are then available for recombination which results in a specific color luminescence indicative of the type of laser source.

Abstract: Method for marking objects by the use of memory micro-crystals, consisting in choosing one or several micro-crystals, of doping each micro-crystal, if this has not already occurred naturally, with any one of the rare earths and transitional metals, in irradiating the micro-crystal or micro-crystals with high-energy rays or particles, according to a predetermined dosage in order to trap the charge carriers, released by ionization of the atoms, while in their energetically metastable state, said process consisting also in applying a predetermined quantity of the micro-crystal or micro-crystals irradiated by said method, to at least one predetermined part of the object, and in safely recording, for the purpose of later comparison, the characteristics, implantation and conditions under which dopage and irradiation of the micro-crystal or micro-crystals took place. Application to the authentication of objects.

Abstract: Apparatuses and methods for rapidly reading phosphors to determine the amount of energy stored therein. The stored energy is interpreted as a measure of the total exposure of the phosphor to ionizing radiation. The 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 at a desired value or values which can vary with time. A shutter or other laser beam interruption means is used to control exposure of the 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 phosphor emits a visible or otherwise detectable emission which is measured as an indication of the radiation exposure of the phosphors. Also disclosed are preferred signal processing and control circuits including one system using a digital computer.

Abstract: A stimulable phosphor sheet carrying a radiation image stored thereon is mounted on a first rotary plate, and a stimulating light beam is projected onto the sheet while the first rotary plate is rotated, thereby effecting main scanning of the sheet by the stimulating light beam. The stimulating light beam is moved relative to the first rotary plate in a radial direction of the first rotary plate to effect sub-scanning of the sheet by the stimulating light beam. Light emitted by the sheet upon stimulation by the stimulating light beam is photoelectrically detected by a photoelectric converter, thereby obtaining an image signal.

Abstract: Detection of surface impurity phases in high-temperature superconducting materials. Thermally stimulated luminescence has been found to occur in insulating impurity phases which commonly exist in high-temperature superconducting materials. The present invention is sensitive to impurity phases occurring at a level of less than 1% with a probe depth of about 1 .mu.m which is the region of interest for many superconductivity applications. Spectroscopic and spatial resolution of the emitted light from a sample permits identification and location of the impurity species. Absence of luminescence, and thus of insulating phases, can be correlated with low values of rf surface resistance.

Abstract: Apparatuses and methods 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 at a desired value or values which can vary with time. 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 opitcal 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 thermoluminscent phosphors.

Abstract: A thermoluminescence dosimetry (TLD) card reader includes at least one light detector for detecting light emitted by a heated thermoluminescent element and a heater for heating each TL element. The heater includes a conduit for channeling a flow of gas from a gas source and for discharging heated gas against a TL element, along with means for heating the conduit for transferring heat from it to the gas flowing through it. Preferably, the conduit is electrically conducting and an electrical current is passed through it via leads joined to the conduit near its inlet and outlet ends to heat the tube. A thermocouple disposed proximate the outlet end of the conduit for measuring the temperature of the gas being discharged from the tube, provides an electrical signal to a controllable electrical current source connected to the leads so that the temperature of the gas being discharged from the conduit may be controlled according to a prescribed relationship.

Abstract: A novel apparatus and fully automatic, computer implemented method for making radiation dose measurements using composite glow curve data obtained with a thermoluminescent dosimetry reader wherein such composite glow curve data is composed of the superposition of plural overlapping glow peaks plus instrumental and dosimeter background. The background component of the composite glow curve is subtracted out by using an automatic peak search technique followed by individual chip background subtraction based upon the extrapolation of the background curve under the glow curve by fitting on both sides of the curve outside the region of the peaks. Following background subtraction and automatic identification of low temperature signal limits, the leading edges of higher temperature dosimetric peaks are extrapolated to lower temperatures to subtract from the glow curve a lower temperature dosimetric peak without affecting the higher temperature dosimetric peaks.

Abstract: A novel apparatus and fully automatic, computer implemented method for making radiation dose measurements using composite glow curve data obtained with a thermoluminescent dosimetry reader wherein such composite glow curve data is composed of the superposition of plural overlapping glow peaks plus instrumental and dosimeter background. The background component of the composite glow curve is subtracted out by using an automatic peak search technique followed by individual chip background subtraction based upon the extrapolation of the background curve under the glow curve by fitting on both sides of the curve outside the region of the peaks. Following background subtraction and automatic identification of low temperature signal limits, the leading edges of higher temperature dosimetric peaks are extrapolated to lower temperatures to subtract from the glow curve a lower temperature dosimetric peak without affecting the higher temperature dosimetric peaks.

Abstract: Thin layer thermoluminescent radiation dosimeters for use in laser readable dosimetry systems, and methods of fabricating such thin layer dosimeters. The thin layer thermoluminescent radiation dosimeters include a thin substrate made from glass or other inorganic materials capable of withstanding high temperatures and high heating rates. A thin layer of a thermoluminescent phoshphor material is heat bonded to the substrate using an inorganic binder such as glass. The dosimeters can be mounted in frames and cases for ease in handling. Methods of the invention include mixing a suitable phosphor composition and binder, both being in particulate or granular form. The mixture is then deposited onto a substrate such as by using mask printing techniques. The dosimeters are thereafter heated to fuse and bond the binder and phosphor to the substrate.

Abstract: A method of determining the nuclear radiation dosage to which a thermoluminescent crystal, such as a diamond or cubic boron nitride crystal, has previously been subjected, involves the steps of heating the cyrstal up while supporting it against gravity on an upwardly flowing stream of gas. The light which the crystal emits is collected and analyzed to give a radiation dosage measure in accordance with a know relationship between amount of collected light and radiation dosage. The gas stream may be a hot gas stream in which case the hot gas also serves to heat up the crystal. In one embodiment of the invention, the crystal is supported and heated up inside an integrating sphere which collects the emitted light.

Abstract: In 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,the improvement in which at least the front end of the phosphor sheet is provided with a stiff reinforcing member extending along said end: orthe improvement in which at least a portion on the back surface adjoining the front end of the phosphor sheet is provided with a stiff reinforcing member extending in the width direction.

Abstract: A passive device for measuring environmental radioactivity employs three radiation detectors enclosed in a small shielded housing. A first radiation detector generates a first signal responsive to an amount of radioactivity produced over a period of time by radioactive gas diffused in the volume of air inside the housing. The first radiation detector includes at least one thermoluminescence dosimeter mounted in close proximity to an electret. A second radiation detector generates a second signal responsive to an amount of environmental gamma radiation over the period of time, and also includes at least one thermoluminescence dosimeter. A third radiation detector generates a third signal indicative of an amount of fading of the second signal over the period of time, the third radiation detector also including at least one thermoluminescene dosimeter having an initially predetermined third signal.

Abstract: A remote sensing device comprising light generating means positioned in the vicinity of an event being measured and means for conducting the generated light to a remote location. The light generating means advantageously comprises an optical emission mechanical transducer or bioluminescent device, or current generating means coupled with a light emitting diode, semiconductor laser or filament bulb. Also disclosed is a method according to the invention.

Abstract: A device for monitoring the irradiation of bulk material composed of a carrier body having an outer surface formed to present a plurality of facets and constructed to receive a radiation sensor on each facet; and a plurality of radiation sensors each removably mounted on a respective facet of the carrier body.

Abstract: Diamond having a nitrogen content not exceeding 100 ppm and electrons or holes trapped at lattice imperfections within the crystal structure has been found to be a good thermoluminescent material. The diamond is produced by taking a diamond having a nitrogen content not exceeding 100 ppm and subjecting it to nuclear radiation.