CN110361769B - Quasi-real-time gamma dose rate measuring device based on pulsed light release technology - Google Patents
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- G01T1/02—Dosimeters
- G01T1/10—Luminescent dosimeters
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Abstract
The invention relates to the technical field of nuclear radiation detection, and provides a quasi-real-time gamma dose rate measuring device based on a pulse light-releasing technology, which comprises a detector, two series optical fibers, an optical fiber adapter and a photoelectric control box, wherein the two series optical fibers are connected through the optical fiber adapter, the end faces of the two optical fibers are in close contact after the two optical fibers are connected, the detector is installed in a radiation field, the photoelectric control box is installed in a place where people live in, the length of each optical fiber can be more than 50m, and remote measurement of dose rate can be realized. The device has the characteristics of miniaturization, dense point distribution, strong anti-electromagnetic interference capability, high sensitivity, wide measurement range, remote measurement and control and the like.
Description
Technical Field
The invention relates to the technical field of nuclear radiation detection, in particular to a quasi-real-time gamma dose rate measuring device based on a pulse light-release technology, which is used for remote measurement of gamma radiation field dose rate and is particularly suitable for occasions where the measured position has complicated electromagnetic environment, narrow space, wide dose rate range and needs dense point distribution for three-dimensional radiation field measurement.
Background
At present, ionization chamber detectors, scintillator detectors, gas detectors and the like are generally used for measuring the dose rate of a gamma radiation field, and the detectors are generally large in size, cannot be used in narrow space, are difficult to distribute points in a large range, and cannot realize measurement of a three-dimensional radiation field. Such detectors usually need to include a pre-signal processing circuit to process the output signal of the sensor, otherwise, the output signal cannot be transmitted over a long distance, and the electronic devices used are usually poor in irradiation resistance and are easily interfered by external electromagnetic fields. The output pulse width of such detector probes is typically on the order of μ s, and the measurement range is limited by non-linear effects caused by pulse pile-up.
Currently, photoluminescent materials have been widely used in the field of personal dose monitoring, the measurement object is cumulative radiation exposure dose, and although photoluminescent materials have also been proposed in recent years for dose rate measurement, there is no mature application until now due to system complexity, realizability, and the like.
Both the monitoring of the dose rate in a radioactive waste treatment place and the measurement of a three-dimensional radiation field of a nuclear power ship reactor cabin need to use a dose rate measuring device which has the characteristics of strong electromagnetic interference resistance, miniaturization and remote control.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a quasi-real-time gamma dose rate measuring device based on a pulse light-releasing technology, and the device has the characteristics of miniaturization, dense point distribution, strong anti-electromagnetic interference capability, high sensitivity, wide measuring range, remote measurement and control and the like.
In order to achieve the purpose, the invention adopts the following technical scheme.
The utility model provides a quasi real-time gamma dose rate measuring device based on light technique is explained to pulsed light, includes detector, two optical fiber, optical fiber adapter and photoelectric control box of establishing ties, and two optical fiber of establishing ties pass through the optical fiber adapter to be connected, connect the terminal surface in close contact with of two optic fibers in back, the detector is installed in the radiation field, the photoelectric control box is installed in the place that personnel are suitable for to live, optical fiber length can be greater than 50m, can realize the remote measurement of dose rate.
In the above technical scheme, the detector comprises a detector cylinder, a light guide cone, a lens, a gasket, a positioning snap ring, a light-releasing material, a reflector and a detector end cover. The assembly mode of the detector is as follows: firstly, placing a light guide cone into a detector cylinder, then placing a lens, screwing a positioning clamp ring into the detector cylinder until screwing, sequentially installing a light-releasing material and a reflector in 2 clamp grooves of the positioning clamp ring, finally installing a gasket, and screwing a detector end cover onto the detector cylinder until screwing.
In the technical scheme, the typical size of the detector is ϕ mm × 30mm, the detector is small in size, large-range dense point distribution can be carried out, and measurement of dose rate gradients and three-dimensional radiation fields can be achieved.
In the technical scheme, no electronic device or cable is arranged in the detector, and the anti-electromagnetic interference capability is strong.
In the above technical solution, the light guide cone is made of stainless steel, the inner surface of the light guide cone is precisely polished and can be plated with an Al film or an Ag film, the inner diameter of the small opening is slightly larger than the diameter of the fiber core of the optical fiber, and the inner diameter of the large opening is slightly larger than the diameter of the light release material.
In the technical scheme, the lens is an aspheric lens, the aspheric side is close to the light-releasing material, the clear aperture is larger than the diameter of the light-releasing material, the surfaces on the two sides are plated with antireflection films, and the average reflectivity at the wavelength of 350nm-550nm is less than 0.5% (on each surface).
In the above technical solution, the light-releasing material is Al 2 O 3 C crystal or powder tablet, the typical size is ϕ mm x 0.3mm, the photoluminescent material mainly generates photoluminescent fluorescence with the service life of about 35ms, the wavelength peak value of about 420nm and the full width at half maximum of about 60nm when being irradiated by excitation light after being irradiated by radiation, the photoluminescent material has high sensitivity and low measurement lower limit (the lower limit of dosage rate measurement is 10 mu Gy/h magnitude), the photoluminescent fluorescence emitted by the photoluminescent material has long service life, and the pulse pair resolution is not more than 20ns and the measurement range is wide (more than 6 magnitude) through measurement by a single photon counting mode.
In the technical scheme, the reflector is a broadband dielectric film reflector, one side of the dielectric film is close to the light release material, and the average reflectivity at the wavelength of 350nm-550nm is more than 98%.
In the technical scheme, the optical fiber is a large-core high-hydroxyl quartz optical fiber with a numerical aperture typical value of 0.22, antireflection films are plated at two ends of the large-core high-hydroxyl quartz optical fiber, the average reflectivity at the wavelength of 350-550 nm is less than 0.5% (each surface), the attenuation coefficient at the wavelength of 400nm is less than 50dB/km, the two optical fibers are connected in series through an optical fiber adapter, wherein the 1 st optical fiber is connected with a detector and has a length of 1-2 m, the end face of a fiber core is hexagonal or octagonal, the diameter typical value of a circumscribed circle is 1000 mu m, the 2 nd optical fiber is connected with an optoelectronic control box, the length can be more than 50m, the end face of the fiber core is circular, and the diameter typical value is 1000 mu m.
In the above technical solution, the photoelectric control box includes a laser, a shutter, a laser mirror, a laser filter, a photodiode, a dichroic mirror, 2 lenses, a fiber connector, a lens sleeve, 3 fluorescent filters, a photomultiplier, and a timing control and signal processing unit.
In the technical scheme, the laser is a diode-pumped Nd-YAG solid pulse laser with a Q-switching function, the outgoing laser wavelength is 532nm, the maximum external trigger frequency is not less than 4kHz, the pulse width is less than 1 mus, and the average pulse energy is not less than 25 muJ (4 kHz).
In the technical scheme, the shutter is a blade type mechanical shutter, the blades are plated with low-reflectivity polytetrafluoroethylene, the switching time is not more than 3ms, and the shutter can be controlled by an external TTL/CMOS signal.
In the technical scheme, the laser reflector is a dielectric film reflector, the reflectivity of the laser reflector at the wavelength of 530nm-534nm is more than 98%, the laser filter is a dielectric film band-pass filter, the transmissivity of the laser reflector at the wavelength of 530nm-534nm is more than 96%, the optical density of the laser reflector at the wavelength of 350nm-480nm is not less than 6, the dichroic mirror is a long-wave-pass dichroic mirror, the transmissivity of the laser reflector at the wavelength of 530nm-534nm is more than 95%, and the reflectivity of the laser reflector at the wavelength of 350nm-480nm is more than 96%.
In the above technical solution, the photodiode monitors the power stability of the laser by measuring the pulse energy of the reflected excitation light of the dichroic mirror.
In the above technical solution, the 2 lenses are aspheric lenses, the surfaces on both sides are plated with antireflection films, and the average reflectivity at the wavelength of 350nm to 550nm is less than 0.5% (on each surface), wherein the 1 st lens is used for focusing the excitation light and collimating the photoluminescence fluorescence, and the 2 nd lens is used for focusing the photoluminescence fluorescence.
In the technical scheme, 2 of the 3 fluorescent filters are dielectric film band-pass filters, the optical density of the wavelength of 530nm-534nm is not less than 6, the average transmittance of the wavelength of 350nm-480nm is not less than 95%, the other 1 fluorescent filter is a color glass filter (or a color filter of a corresponding mark produced by other companies) which is produced by a Schottky company and has the thickness of 1mm-2mm and the mark of BG3, antireflection films are plated on the surfaces of two sides, and the average reflectivity of the wavelength of 350nm-550nm is less than 0.5% (each surface).
In the technical scheme, the fluorescent filter is sequentially arranged inside the lens sleeve according to the sequence of the dielectric film band-pass filter, the colored glass filter and the dielectric film band-pass filter, the lens sleeve is tightly connected with the photomultiplier through the black silica gel gasket and the bolt, and the joint is light-tight.
In the above technical scheme, the photomultiplier is a gated photomultiplier suitable for single photon counting applications through screening, and the amplification factor is not less than 2 × 10 6 The pulse rise time is not more than 2ns, the dark count rate is not more than 10cps, the entrance window is borosilicate glass, the photocathode is a double-alkali or super-double-alkali material with the radiation sensitivity peak value of not less than 88mA/W (420 nm), the typical value of the effective diameter of the photocathode is 8mm, the minimum pulse width of a gating signal is not more than 1 mus, the minimum repetition frequency is not less than 10kHz, and the rise time and the fall time are not more than 100ns.
In the above technical solution, the timing control and signal processing unit includes a timing control circuit and a signal processing circuit, the timing control circuit is used for controlling the on-off states of the laser, the shutter and the photomultiplier, the signal processing circuit amplifies, discriminates, shapes and counts the current pulse signal output by the photomultiplier, the input bandwidth of the signal processing circuit is not less than 300MHz, and the signal processing circuit has a fixed pulse-pair resolution (pulse-pair resolution) not greater than 20 ns.
When the device is used for measuring the dosage rate, exciting light emitted by a laser device irradiates a light-releasing material in a detector after passing through a dichroic mirror and an optical fiber, the light-releasing material emits light-releasing fluorescence after being irradiated by the exciting light, the light-releasing fluorescence is reflected to a photocathode of a photomultiplier tube by the dichroic mirror after passing through the optical fiber and then counted, a counting value is in direct proportion to the cumulative radiation irradiation dose received by the light-releasing material, and the dosage rate is obtained by the ratio of the difference of the cumulative dose measurement values of the two times before and after the measurement to the time difference of the two times before and after the measurement.
The detector of the quasi-real-time gamma dose rate measuring device based on the pulse light and light release technology has the size of cm magnitude, is much smaller than that of the traditional dose rate detector, can be used in a narrow space, and can also realize the measurement of dose rate gradient and three-dimensional radiation field through large-range intensive point distribution.
Drawings
Fig. 1 is a general assembly schematic diagram of a quasi-real-time gamma dose rate measuring device based on a pulsed light-release technology.
Fig. 2 is a schematic structural diagram of a quasi-real-time gamma dose rate measuring device detector based on a pulsed light-release technology.
Fig. 3 isbase:Sub>A sectional viewbase:Sub>A-base:Sub>A in fig. 2.
Fig. 4 is a schematic structural diagram of a photoelectric control box of the quasi-real-time gamma dose rate measuring device based on the pulsed light-release technology.
Wherein: 1. the detector, 2, a first optical fiber, 3, an optical fiber adapter, 4, a second optical fiber, 5, a photoelectric control box, 6, a detector cylinder, 7, a light guide cone, 8, a first lens, 9, a gasket, 10, a positioning snap ring, 11, a light release material, 12, a reflector, 13, a detector end cover, 14, a laser, 15, a shutter, 16, a laser reflector, 17, a laser filter, 18, a photodiode, 19, a dichroic mirror, 20, a second lens, 21, an optical fiber connector, 22, a lens sleeve, 23, a third lens, 24, a first fluorescent filter, 25, a second fluorescent filter, 26, a third fluorescent filter, 27, a photomultiplier, 28, a timing control unit and a signal processing unit.
Detailed Description
The following detailed description is provided to enable a further understanding of the objects, features and advantages of the invention, when considered in connection with the accompanying drawings.
As shown in fig. 1, the present embodiment provides a quasi-real-time gamma dose rate measuring apparatus based on a pulsed light-release technique, where the measuring apparatus includes a detector 1, a first optical fiber 2, an optical fiber adapter 3, a second optical fiber 4, and a photoelectric control box 5, the detector 1 is installed in a radiation field, and the photoelectric control box 5 is installed in a place where people live in.
In the above embodiment, when the dose rate is measured, the excitation light emitted by the laser 14 is transmitted by the dichroic mirror 19 and then irradiates the light-releasing material 11 in the detector 1 through the second optical fiber 4 and the first optical fiber 2, the light-releasing material 11 emits light-releasing fluorescence after being irradiated by the excitation light, the light-releasing fluorescence is reflected to the photocathode of the photomultiplier 27 by the dichroic mirror 19 after passing through the first optical fiber 2 and the second optical fiber 4, and then is counted, the counted value is in direct proportion to the cumulative radiation irradiation dose received by the light-releasing material 11, and the dose rate is obtained by the ratio of the difference between the two cumulative dose measured values before and after the measurement to the time difference between the two sides before and after the measurement.
As shown in fig. 2 and 3, in the above embodiment, the detector 1 includes a detector cylinder 6, a light guide cone 7, a first lens 8, a gasket 9, a positioning snap ring 10, an optical luminescence material 11, a reflector 12, and a detector end cap 13, and a typical size of the detector 1 is ϕ mm × 11mm × 30mm.
In the above embodiment, one end of the probe cylinder 6 is an optical fiber connector, the inner surface of the other end is an internal thread, and the outer surface is an external thread, which are respectively matched with the external thread of the positioning snap ring 10 and the internal thread of the probe end cover 13.
In the above embodiment, the light guide cone 7 is made of stainless steel, the inner surface of the light guide cone is precisely polished and can be plated with an Al film or an Ag film, the inner diameter of the small opening is slightly larger than the diameter of the core of the optical fiber 2, and the inner diameter of the large opening is slightly larger than the diameter of the light-releasing material 11.
In the above embodiment, the first lens 8 is an aspheric lens, the aspheric side of which is adjacent to the light-releasing material 11, the clear aperture is larger than the diameter of the light-releasing material 11, the surfaces on both sides are coated with antireflection films, and the average reflectivity at the wavelength of 350nm to 550nm is less than 0.5% (per surface).
In the above embodiment, the outer side of the positioning snap ring 10 is an external thread, the inner side of the positioning snap ring includes 2 snap grooves, the diameter of the 1 st snap groove is equal to the diameter of the light-emitting material 11 for mounting the light-emitting material 11, three protrusions on the snap grooves are used for supporting and fixing the light-emitting material 11, and the diameter of the 2 nd snap groove is equal to the diameter of the reflector 12 for mounting the reflector 12.
In the above embodiment, the light-emitting material 11 is Al 2 O 3 C crystal or powder compact, typical size is ϕ mm x 0.3mm, the light-releasing material 11 mainly generates light-releasing fluorescence with lifetime of about 35ms, wavelength peak of about 420nm and half-height width of about 60nm when irradiated by excitation light after being irradiated by radiation.
In the above embodiment, the reflector 12 is a broadband dielectric film reflector, one side of the dielectric film is close to the light-releasing material 11, and the average reflectivity at the wavelength of 350nm to 550nm is greater than 98%.
In the above embodiment, the ratio of the difference between the radius of the photoluminescent material 11 and the radius of the core circumscribed circle of the first optical fiber 2 to the focal length of the first lens 8 is approximately equal to the numerical aperture of the first optical fiber 2.
In the above embodiment, the assembly manner of the detector 1 is as follows: firstly, a light guide cone 7 is placed in a detector cylinder 6, then a first lens 8 is placed, a positioning snap ring 10 is screwed into the detector cylinder 6 until the detector cylinder is screwed up (two round holes on the end face of the positioning snap ring 10 are utilized), a light-releasing material 11 and a reflector 12 are sequentially installed in 2 clamping grooves of the positioning snap ring 10, finally a gasket 9 is installed, and a detector end cover 13 is screwed on the upper edge of the detector cylinder 6 until the detector cylinder is screwed up.
In the above embodiment, the first optical fiber 2 is a large-core high-hydroxyl silica optical fiber with a length of 1m to 2m, the end face of the core is hexagonal or octagonal, the typical value of the diameter of the circumscribed circle is 1000 μm, the typical value of the numerical aperture is 0.22, the two ends are coated with antireflection films, the average reflectivity at the wavelength of 350nm to 550nm is less than 0.5% (per surface), the attenuation coefficient at the wavelength of 400nm is less than 50dB/km, and the center point of the end face of the first optical fiber 2 is located at the focus of the first lens 8 after the first optical fiber 2 is connected with the detector 1.
In the above embodiment, the second optical fiber 4 is a large-core high-hydroxyl silica optical fiber with a length of more than 50m, the end face of the fiber core is circular, the typical diameter value is 1000 μm, the typical numerical aperture value is 0.22, both ends are coated with antireflection films, the average reflectivity at the wavelength of 350nm to 550nm is less than 0.5% (per surface), the attenuation coefficient at the wavelength of 400nm is less than 50dB/km, and the center point of the end face of the second optical fiber 4 is located at the focus of the second lens 20 after the second optical fiber 4 is connected with the photoelectric control box 5.
In the above embodiment, the first optical fiber 2 and the second optical fiber 4 are connected by the optical fiber adapter 3, and the end faces of the first optical fiber 2 and the second optical fiber 4 are in close contact after the connection.
As shown in fig. 4, in the above-described embodiment, the photoelectric control box 5 includes a laser 14, a shutter 15, a laser mirror 16, a laser filter 17, a photodiode 18, a dichroic mirror 19, a second lens 20, an optical fiber connector 21, a lens sleeve 22, a third lens 23, a first fluorescent filter 24, a second fluorescent filter 25, a third fluorescent filter 26, a photomultiplier 27, and a timing control and signal processing unit 28.
In the above embodiment, the laser 14 is a diode-pumped Nd: YAG solid pulse laser with Q-switching function, the outgoing laser wavelength is 532nm, the maximum external trigger frequency is not less than 4kHz, the pulse width is less than 1 mus, and the average pulse energy is not less than 25 muJ (4 kHz).
In the above embodiment, the shutter 15 is a mechanical shutter with blades coated with low-reflectivity teflon, and the switching time is not more than 3ms, which can be controlled by external TTL/CMOS signals.
In the above embodiment, the laser mirror 16 is a dielectric film mirror, and the reflectance at the wavelength of 530nm to 534nm is greater than 98%. The laser filter 17 is a dielectric film band-pass filter, the transmittance of the wavelength of 530nm-534nm is greater than 96%, the optical density of the wavelength of 350nm-480nm is not less than 6, the dichroic mirror 19 is a long-wave pass dichroic mirror, the transmittance of the wavelength of 530nm-534nm is greater than 95%, and the reflectance of the wavelength of 350nm-480nm is greater than 96%.
In the above embodiment, the photodiode 18 monitors the power stability of the laser 14 by measuring the pulse energy of the reflected excitation light of the dichroic mirror 19.
In the above embodiment, the second lens 20 and the third lens 23 are aspheric lenses, the two side surfaces are coated with antireflection films, the average reflectivity at the wavelength of 350nm to 550nm is less than 0.5% (on each surface), the second lens 20 is used for focusing the excitation light and collimating the luminescence light, and the third lens 23 is used for focusing the luminescence light.
In the above embodiment, the first fluorescent filter 24 and the third fluorescent filter 26 are dielectric film bandpass filters, the optical density at a wavelength of 530nm to 534nm is not less than 6, the average transmittance at a wavelength of 350nm to 480nm is not less than 95%, the second fluorescent filter 25 is a color glass filter (or a color filter of a corresponding brand produced by other companies) produced by schottky corporation, the thickness of which is 1mm to 2mm, the brand of which is BG3, the surfaces of both sides of the color glass filter are plated with antireflection films, and the average reflectance at a wavelength of 350nm to 550nm is less than 0.5% (each surface).
In the above embodiment, the first fluorescent filter 24, the second fluorescent filter 25 and the third fluorescent filter 26 are sequentially installed inside the lens sleeve 22, the lens sleeve 22 and the photomultiplier 27 are tightly connected through a black silica gel gasket and a bolt, and the joint is light-tight.
In the above embodiment, the photomultiplier 27 is a gated photomultiplier for single photon counting applications, which has been screened to have a magnification of not less than 2 × 10 6 The pulse rise time is not more than 2ns, the dark count rate is not more than 10cps, the entrance window is borosilicate glass, the photocathode is a double-alkali material or super double-alkali material with the radiation sensitivity peak value of not less than 88mA/W (420 nm), the typical value of the effective diameter of the photocathode is 8mm, the minimum pulse width of a gating signal is not more than 1 mus, the minimum repetition frequency is not less than 10kHz, and the rise time and the fall time are not more than 100ns.
In the above embodiment, the timing control and signal processing unit 28 includes a timing control circuit for controlling the on/off states of the laser 14, the shutter 15 and the photomultiplier 27, and a signal processing circuit for amplifying, screening, shaping and counting the current pulse signal output from the photomultiplier 27, the input bandwidth of which is not less than 300MHz, and which has a fixed pulse pair resolution of not more than 20 ns.
Those matters not described in detail in this specification are well within the knowledge of those skilled in the art.
It will be understood by those skilled in the art that the foregoing is merely a preferred embodiment of the present invention, and is not intended to limit the invention, such that any modification, equivalent replacement or improvement made within the spirit and principle of the present invention shall be included within the scope of the present invention.
Claims (9)
1. A quasi-real-time gamma dose rate measuring device based on pulse light-release technology is characterized in that: the detector comprises a detector, two optical fibers connected in series, an optical fiber adapter and a photoelectric control box, wherein the two optical fibers connected in series are connected through the optical fiber adapter, the end faces of the two optical fibers are in close contact after the two optical fibers are connected, the detector comprises a detector barrel, a light guide cone, a lens, a gasket, a positioning snap ring, a light release material, a reflector and a detector end cover, one end of the detector barrel is an optical fiber connector, the inner surface of the other end of the detector barrel is an internal thread, the outer surface of the detector barrel is an external thread, the internal thread is matched with the external thread of the positioning snap ring and the internal thread of the detector end cover, the light guide cone, the lens, the positioning snap ring, the light release material and the reflector are sequentially arranged in the detector barrel, the lens is an aspheric lens, the aspheric side of the aspheric surface is close to the light release material, the light release material and the reflector are respectively arranged in 2 clamping grooves of the positioning snap ring, the reflector is a broadband dielectric film reflector, one side of the dielectric film is close to the light release material, the positioning snap ring is fixed with the detector barrel through a thread, and the gasket and the detector end cover are additionally arranged at the end cover; the photoelectric control box comprises a laser, a shutter, a laser reflector, a laser filter, a photodiode, a dichroic mirror, 2 lenses, a fiber connector, a lens sleeve, 3 fluorescent filters, a photomultiplier, a time sequence control and signal processing unit, wherein the fluorescent filters are sequentially arranged inside the lens sleeve according to the sequence of a dielectric film band-pass filter, a colored glass filter and a dielectric film band-pass filter, the lens sleeve is tightly connected with the photomultiplier through a black silica gel gasket and a bolt, and the joint is light-tight; the optical fiber is a large-core-diameter high-hydroxyl quartz optical fiber with a numerical aperture of 0.22, the two ends of the optical fiber are plated with antireflection films, the average reflectivity of each surface at the wavelength of 350-550 nm is less than 0.5%, the attenuation coefficient at the wavelength of 400nm is less than 50dB/km, the two optical fibers are connected in series through an optical fiber adapter, wherein the 1 st optical fiber is connected with the detector, the length of the 1 st optical fiber is 1-2 m, the end face of the fiber core is hexagonal or octagonal, the diameter of an external circle is 1000 mu m, the 2 nd optical fiber is connected with an optoelectronic control box, the end face of the fiber core is circular, and the diameter of the fiber core is 1000 mu m.
2. The quasi-real-time gamma dose rate measuring device based on the pulsed light luminescence technology according to claim 1, wherein: the size of the detector is ϕ mm x 30mm.
3. The quasi-real-time gamma dose rate measuring device based on the pulsed light extraction technology according to claim 1, characterized in that: the light guide cone is made of stainless steel, the inner surface of the light guide cone is precisely polished and can be plated with an Al film or an Ag film, the inner diameter of the small opening is slightly larger than the diameter of the fiber core of the optical fiber, the inner diameter of the large opening is slightly larger than the diameter of the light-releasing material, and the light-releasing material is Al 2 O 3 C crystal or powder tablet with the size of ϕ mm x 0.3mm.
4. The quasi-real-time gamma dose rate measuring device based on the pulsed light extraction technology according to claim 1, characterized in that: the clear aperture of a lens in the detector is larger than the diameter of the light-releasing material, antireflection films are plated on the surfaces of two sides, and the average reflectivity of each surface at the wavelength of 350-550 nm is less than 0.5%.
5. The quasi-real-time gamma dose rate measuring device based on the pulsed light extraction technology according to claim 1, characterized in that: the average reflectivity of the reflector at the wavelength of 350nm-550nm is more than 98%.
6. The quasi-real-time gamma dose rate measuring device based on the pulsed light extraction technology according to claim 1, characterized in that: YAG solid pulse laser, the outgoing laser wavelength is 532nm, the maximum external trigger frequency is not less than 4kHz, the pulse width is less than 1 mus, and the average pulse energy is not less than 25 muJ; the shutter is a blade type mechanical shutter, low-reflectivity polytetrafluoroethylene is plated on the blades, the switching time is not more than 3ms, and the shutter is controlled through an external TTL/CMOS signal.
7. The quasi-real-time gamma dose rate measuring device based on the pulsed light extraction technology according to claim 1, characterized in that: the laser reflector is a dielectric film reflector, and the reflectivity of the 530nm-534nm wavelength is more than 98%; the laser filter is a dielectric film band-pass filter, the transmissivity of the wavelength of 530nm-534nm is more than 96%, and the optical density of the wavelength of 350nm-480nm is not less than 6; the dichroic mirror is a long-wave-pass dichroic mirror, the transmittance of the wavelength of 530nm-534nm is greater than 95%, and the reflectance of the wavelength of 350nm-480nm is greater than 96%; 2 lenses in the photoelectric control box are aspheric lenses, the surfaces on two sides are plated with antireflection films, the average reflectivity of each surface at the wavelength of 350nm-550nm is less than 0.5%, wherein the 1 st lens is used for focusing exciting light and collimating photoluminescent light, and the 2 nd lens is used for focusing photoluminescent light; 2 of the 3 fluorescent filters are dielectric film band-pass filters, the optical density of the wavelength of 530nm-534nm is not less than 6, the average transmittance of the wavelength of 350nm-480nm is not less than 95%, the other 1 is a color glass filter which is produced by Schottky and has the thickness of 1mm-2mm and the brand number of BG3, the surfaces of two sides are plated with antireflection films, and the average reflectance of each surface at the wavelength of 350nm-550nm is less than 0.5%.
8. The quasi-real-time gamma dose rate measuring device based on the pulsed light extraction technology according to claim 1, characterized in that: the photomultiplier is a gate-controlled photomultiplier applicable to single photon counting, and the amplification factor is not less than 2 multiplied by 10 6 The pulse rise time is not more than 2ns, the dark count rate is not more than 10cps, the entrance window is borosilicate glass, the photocathode is double-alkali material, the minimum pulse width of the gate control signal is not more than 1 mus, the minimum repetition frequency is not less than 10kHz, and the rise time and the fall time are not more than 100ns.
9. The quasi-real-time gamma dose rate measuring device based on the pulsed light extraction technology according to claim 1, characterized in that: the input bandwidth of the timing control and signal processing unit is not less than 300MHz, and the input bandwidth has fixed pulse pair resolution which is not more than 20 ns.
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| US6087666A (en) * | 1998-02-18 | 2000-07-11 | The United States Of America As Represented By The Secretary Of The Navy | Optically stimulated luminescent fiber optic radiation dosimeter |
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| FR2826733B1 (en) * | 2001-07-02 | 2003-09-05 | Commissariat Energie Atomique | RADIATION SENSOR, WITH ENERGY COMPENSATION AND LARGE ANGULAR OPENING, FOR REMOTE DOSIMETRY, AND DOSIMETRY DEVICE USING THE SENSOR |
| WO2004106972A2 (en) * | 2003-05-23 | 2004-12-09 | The Board Of Regents For Oklahoma State University | Optically stimulated luminescence radiation dosimetry method to determine dose rates during radiotherapy procedures |
| CA2811190A1 (en) * | 2010-09-15 | 2012-03-22 | Landauer, Inc. | Portable dosimeter |
| NZ588050A (en) * | 2010-09-17 | 2013-03-28 | Ind Res Ltd | Recording dose information about ionizing radiation absored and stored in a dosimeter |
| GB2515964B (en) * | 2012-06-22 | 2016-03-02 | Landauer Inc | Method and apparatus for fast determination of unknown radiation dose |
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| CN207318732U (en) * | 2017-05-10 | 2018-05-04 | 中山大学 | One kind is based on LiMgPO4:The light of Tm, Tb release the measuring system of light fibre-optical dosimeter |
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