Portable low-energy ray detection device and preparation method thereof

Abstract

The invention discloses a portable low-energy ray detection device and a preparation method thereof, and belongs to the technical field of radiation monitoring. The device aims at solving the problems that a traditional X or gamma ray detector is large in size, high in cost, complex in operation and insufficient in low-energy ray detection sensitivity. According to the technical scheme, an optical fiber probe module is composed of an optical fiber core, a cylindrical aluminum foil mold and a composite scintillator layer, a Cs3Cu2I5: Mn < 2 + > 15% scintillator material and UV glue mixture is injected into an annular cavity of the mold and cured to absorb low-energy X or gamma rays and emit fluorescence, and the cylindrical aluminum foil mold serves as a reflecting layer; the optical fiber probe module is packaged through a 3D printing optical fiber cap, and the output end is coupled with the photocell to realize photoelectric conversion; the alarm circuit control module adopts a triode control circuit to drive a light emitting diode to emit light. The device is small in size, low in cost and suitable for real-time monitoring and alarming of low-energy rays in environments such as medical radiation departments and the like, and personnel safety is guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of radiation monitoring technology, and more particularly to a portable low-energy ray detection device and a preparation method thereof. Background Art

[0002] With the development of nuclear energy and nuclear technology, nuclear reactions have been widely applied in various fields, including industry, medicine, and scientific research. Nuclear reactions release energy in the form of radiation, and various types of nuclear radiation are present in various nuclear radiation fields. X-rays and gamma rays, due to their high energy and strong penetrating power, are widely used in medical diagnosis, radiotherapy, industrial flaw detection, safety testing, aerospace navigation, and material analysis in scientific research. However, while X-rays benefit humanity, their high energy and strong penetrating power can damage chromosomes in human cells and, in severe cases, even cause cell cancer, posing a health risk to nearby personnel. Therefore, X-ray and gamma ray detection is essential.

[0003] Early designs of X-ray / gamma-ray detectors had low resolution and were relatively complex to operate. Some instruments had separate detectors and signal processing equipment, requiring the appropriate probe to be installed before each use, tailored to the type and intensity of the radiation being detected. This also involved adjusting various parameters. With the rapid development of nuclear technology, nuclear electronics, and microelectronics, X-ray / gamma-ray detectors have gradually become smaller and more multifunctional. The accuracy of existing X-ray / gamma-ray detectors continues to improve, and their types are becoming more diverse. Some detectors now offer real-time monitoring, data transmission, and image display capabilities.

[0004] Currently, most X-ray / gamma-ray detectors used in industry, scientific research, and medicine primarily employ three types of detectors for detecting X-rays. The first type is the ionization chamber, which uses radiation to generate ion pairs within the chamber. An applied voltage is then applied to collect the ion pairs, generating a current or voltage pulse. The radiation intensity is then indirectly measured by analyzing the current or voltage pulse. For example, in 2005, Ren Yichang of Harbin Engineering University designed a high-performance, high-pressure argon ionization chamber as a detector for detecting ambient gamma rays. In 2015, Babak Sharifi et al., researchers at the Iranian Institute of Advanced Technology, developed and calibrated a new toroidal ionization chamber for X-ray beam monitoring and dose measurement in medical diagnostic equipment. In 2020, German researchers Benedikt Kopp et al. used a 61-parallel-plate ionization chamber to detect ion radiation for direct clinical assessment of tissue water equivalent thickness (WET). The second type is the semiconductor detector, which uses radiation to generate electron-hole pairs within the detector. The electric field then collects the charge to form pulses, which are then used to detect radiation intensity and dose. For example, BF Phlips et al. developed a thick intrinsic silicon detector for hard X-ray and gamma-ray detection. In order to withstand the high voltage required for the depletion of 2mm thick silicon, the detector uses a 50 concentric guard ring structure, and the detector structure is relatively complex. DAHRasolonjatovo et al. developed a new X / gamma-ray detector based on CdZnTe semiconductor detectors. Compared with silicon semiconductor detectors, the detection efficiency of CZT detectors in the energy range of 59.5-1836keV is five times higher on average. The third is the scintillation detector, which uses the scintillator to release scintillation light when irradiated by X / gamma rays, and converts the optical signal into an electrical signal through a photoelectric conversion device, amplifies and analyzes the electrical signal, and then indirectly measures the radiation intensity and dose. For example, Liu Lingjian et al. developed a scintillator detector gamma spectrometer in 2016. The scintillator material used was LaBr3:10%Ce 3+ The photoelectric conversion device is a silicon phototransistor (SiPM). Zou Benfei et al. also developed a lanthanum bromide scintillator detector in 2016. This detector uses a chlorine- and cerium-doped lanthanum bromide scintillator (LBC) to detect X-rays and gamma rays. A photomultiplier tube (PMT) converts the optical signal into an electrical signal and amplifies it. The detector is encapsulated in an aluminum alloy housing. In addition to the three types of detectors mentioned above, thermoluminescence (TLU) and photoluminescence (PSL) detectors are also used for X-ray and gamma-ray detection.

[0005] The above-mentioned X / γ-ray detectors each have their own advantages and disadvantages. For example, the X / γ-ray detector using an ionization chamber as a probe has the advantages of a relatively wide measurement range and high probe stability, but its detection efficiency for low-energy rays is relatively low, and the detector is large in size, which is not conducive to the portable design of the X / γ-ray detector. The X / γ-ray detector using a semiconductor detector as a probe has the advantages of high energy resolution and a relatively simple structure, but the epitaxial growth technology of semiconductor crystals such as high-purity germanium is demanding, difficult, and expensive, and is only used in some scientific research institutions and large comprehensive hospitals. In recent years, many scholars have reported that LaAlO3:Eu 3+ 、LaBr3:Ce 3+ Rare earth-doped halide scintillators, such as Gd2O2S:Tb, offer advantages such as high light yield, short decay time, and high energy resolution, making scintillator detectors a renewed research hotspot. While rare earth-doped halides exhibit excellent scintillation properties and are being widely used in certain fields, the scarcity and high production costs of rare earth resources, the severe ecological damage caused by mining, and the radioactivity of some rare earth elements present safety risks in portable X-ray / gamma-ray detectors. Summary of the Invention

[0006] The present invention provides a portable low-energy ray detection device and a preparation method thereof. Through the integrated design of an optical fiber probe, a photocell and an alarm circuit control module, miniaturized, low-cost and highly sensitive low-energy ray detection is achieved, solving the problems of traditional X-ray or gamma-ray detectors being large in size, high in cost, complex in operation and insufficient in sensitivity to low-energy ray detection.

[0007] In order to achieve these objectives and other advantages of the present invention, in a first aspect, the present invention provides a portable low-energy radiation detection device, comprising: A fiber optic probe module comprising: Optical fiber core; A cylindrical aluminum foil mold having a hollow structure, wherein the optical fiber core is inserted into the cylindrical aluminum foil mold, and an annular cavity is formed between the optical fiber core and the cylindrical aluminum foil mold; Composite scintillator layer, Cs3Cu2I5:Mn 2+ A mixture of 15% scintillator material and UV glue is injected into the annular cavity and cured to form the composite scintillator layer, which is used to absorb low-energy X-rays or gamma rays and emit fluorescence outward. The cylindrical aluminum foil mold serves as a reflective layer to reflect the stimulated fluorescence. A 3D printed fiber cap, wherein the fiber probe module is fixedly disposed inside the 3D printed fiber cap to form a complete fiber probe; a photocell, whose photosensitive surface is coupled to the output end of the optical fiber probe and converts the fluorescence signal into an electrical signal; The alarm circuit control module includes a transistor control circuit and a light-emitting diode connected to the transistor control circuit. The photocell is connected to the transistor control circuit. When the transistor control circuit is in a saturated conduction state, the light-emitting diode emits light.

[0008] Preferably, the transistor control circuit specifically includes: NPN transistor, whose emitter e2 is connected to the positive electrode of the light emitting diode, collector c2 is connected to the positive electrode of the power supply through the adjustable resistor R5, and the negative electrode of the light emitting diode is grounded; A PNP transistor, whose emitter e1 is connected to the positive electrode of the power supply through an adjustable resistor R2, and whose collector c1 is connected to both the base b2 of the NPN transistor and one end of the adjustable resistor R1, and the other end of the adjustable resistor R1 is grounded; Among them, the positive electrode of the photocell is connected to the base b1 of the PNP transistor, the negative electrode of the photocell is connected to one end of the adjustable resistor R3 used to protect the photocell, the other end of the adjustable resistor R3 is grounded, and the PNP transistor and the NPN transistor perform cascade amplification on the electrical signal output by the photocell; a control switch is also arranged between the positive electrode of the power supply and the adjustable resistor R2.

[0009] Preferably, the emitter current e2 of the NPN transistor is the current i of the light emitting diode. e2 , the expression is: + , Among them, i e1 is the emitter e1 current of the PNP transistor, i b1 is the base b1 current of the PNP transistor, V c1 is the collector c1 voltage of the PNP transistor, V1 is the power supply voltage, and the photosensitivity of the transistor control circuit is adjusted by adjusting the resistance value of the adjustable resistor R1.

[0010] Preferably, it also includes a 3D printed coupling mold, which is a solid rectangular structure, and a through cylindrical hole is set along the long axis of the rectangular structure, and the aperture of the cylindrical hole is adapted to the outer diameter of the 3D printed optical fiber cap; a groove is also provided at one end of the rectangular structure, and the size of the groove is adapted to the size of the photocell, and the groove is connected to the cylindrical hole, and the optical fiber probe is inserted into the cylindrical hole and fixed, and the output end of the optical fiber probe is facing the groove; the photocell is fixed in the groove, so that the photosensitive surface of the photocell fits the output end of the optical fiber probe.

[0011] Preferably, the Cs3Cu2I5:Mn 2+ In the mixture of 15% scintillator material and UV glue, Cs3Cu2I5:Mn 2+ The mass ratio of 15% scintillator material and UV glue is 0.7~1.3:1; the Cs3Cu2I5:Mn 2+ The preparation method of the mixture of 15% scintillator material and UV glue comprises the following steps: a. weighing Cs3Cu2I5:Mn 2+ 15% scintillator material powder is poured into UV glue; b. Use glass rod to stir thoroughly to make Cs3Cu2I5:Mn 2+ 15% scintillator material powder is evenly dispersed in UV glue; c. Use a 1ml syringe with a 27G ultra-fine dispensing needle to dissolve Cs3Cu2I5:Mn 2+ 15% scintillator material and UV glue mixture is injected into the annular cavity; d. Injection and curing are carried out in 3-4 stages, and after each injection, 220-260 nm UV light is irradiated for 30 s to ensure that Cs3Cu2I5:Mn 2+ The mixture of 15% scintillator material and UV glue is completely cured.

[0012] Preferably, the wall thickness of the 3D printed fiber optic cap is 1 mm, the inner diameter is 3.5 mm, the outer diameter is 4.5 mm, and the length is 18 mm; the material used for the 3D printed fiber optic cap is nylon PA12; the wall thickness of the cylindrical aluminum foil mold is 50 μm-0.1 mm, the length is 17.5 mm, and the inner diameter is 3 mm; the minimum energy measurement threshold of low-energy X-rays or gamma rays is 20 KeV; and the photocell is a 2DU3 silicon photocell.

[0013] Preferably, the composite scintillator layer contains Cs3Cu2I5:Mn 2+ The emission wavelength range of the 15% scintillator material is 400-650nm; the optical fiber core is a PMMA optical fiber core with a diameter of 1.985mm, and the applicable wavelength range of the optical fiber core is 400-700nm; the 3D printed optical fiber cap is hollow cylindrical, with one end being tapered and the other end being open.

[0014] Preferably, the resistance range of the adjustable resistor R1 is set to 300Ω to 20kΩ, so as to detect low-energy X-rays or gamma rays of different intensities; and the power source is a lithium battery.

[0015] Preferably, it further includes a packaging shell, in which the optical fiber probe, the photocell, the alarm circuit control module and the 3D printed coupling mold are all packaged, one end of the packaging shell is conical, the light-emitting diode passes through the shell wall of the packaging shell and is fixedly set on the packaging shell; the control switch passes through the shell wall of the packaging shell and is fixedly set on the packaging shell.

[0016] In a second aspect, the present invention further provides a method for preparing a portable low-energy ray detection device, comprising the following steps: S1. Obtain Cs3Cu2I5:Mn 2+ 15% scintillator material, and Cs3Cu2I5:Mn 2+ 15% is mixed with UV glue as scintillator material to form Cs3Cu2I5:Mn 2+ 15% scintillator material and UV glue mixture; S2, insert the optical fiber core into the cylindrical aluminum foil mold, and Cs3Cu2I5:Mn 2+ A mixture of 15% scintillator material and UV glue is injected into the annular cavity between the optical fiber core and the cylindrical aluminum foil mold. The injection and curing are performed in stages to obtain an optical fiber probe module. During the glue injection process, the optical fiber core must be located at the center of the cylindrical aluminum foil mold. S3. Use a light-curing 3D printer to obtain a 3D-printed fiber cap, inject UV glue into the inner side wall of the 3D-printed fiber cap, insert the fiber probe module into the 3D-printed fiber cap, and use UV glue to encapsulate it to obtain a plastic fiber probe; S4. Use a photocell as a photoelectric conversion device to convert the optical signal into an electrical signal; use a 3D printer to obtain a 3D printed coupling mold, fix the photocell in a groove at one end of the 3D printed coupling mold using UV glue, insert the other end into the output end of the optical fiber probe, and make the photosensitive surface of the photocell fit the output end of the optical fiber probe; S5. Make a PCB circuit board of the alarm circuit control module; S6. Use a 3D printer to obtain a packaging shell, and package the optical fiber probe, the photocell, the 3D printed coupling mold, and the PCB circuit board in the packaging shell.

[0017] The present invention has at least the following beneficial effects: First, the present invention achieves miniaturization and portability through the integrated design of a fiber optic probe, photocell, and alarm circuit control module. The combination of a composite scintillator layer and a cylindrical aluminum foil mold reflective layer improves detection sensitivity for low-energy radiation while reducing costs. The use of a 3D-printed fiber cap further simplifies the packaging process and enhances device reliability.

[0018] Second, the cascaded transistor control circuit design improves the amplification efficiency and stability of the electrical signal. The introduction of an adjustable resistor allows for more flexible sensitivity adjustment, adapting to the detection needs of low-energy radiation of varying intensities and enhancing the device's applicability. The clear current expression and adjustable resistor design simplify the circuit debugging process, making the LED drive current more stable and controllable, and improving the alarm circuit's response speed and accuracy. The wide range of adjustable resistor settings allows the device to flexibly detect low-energy radiation of varying intensities, adapting to a variety of application scenarios and enhancing its versatility.

[0019] Third, the design of the 3D-printed coupling mold achieves precise fixation and efficient coupling between the optical fiber probe and the photocell, reducing losses during signal transmission and improving detection efficiency and signal stability.

[0020] Fourth, optimized Cs3Cu2I5:Mn 2+ The 15% scintillator material and UV adhesive mix and the staged curing process ensure uniformity and performance stability of the composite scintillator layer, improving the detection efficiency and lifespan of the scintillator material. The precisely designed dimensions and material selection of the 3D-printed fiber cap and cylindrical aluminum foil mold enhance the device's portability and low-energy radiation detection efficiency, while reducing manufacturing costs. The matching design of the scintillator material and the fiber core for a specific wavelength range ensures efficient transmission of fluorescence signals and detection sensitivity, enhancing the device's overall performance.

[0021] Fifth, the integrated packaging shell design improves the portability and user-friendliness of the device, while protecting the internal modules from external environmental influences and extending the service life of the device.

[0022] Sixth, the optimized preparation method steps simplify the production process, improve the consistency and performance stability of the device, reduce manufacturing costs, and facilitate large-scale promotion and application.

[0023] Other advantages, objectives and features of the present invention will be reflected in part from the following description and will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic cross-sectional view of the optical fiber probe in the portable low-energy ray detection device of the present invention; Figure 2 This is a schematic diagram of the structure of the 3D printed optical fiber cap in the portable low-energy ray detection device of the present invention; Figure 3 This is a schematic structural diagram of a 3D printed coupling mold in the portable low-energy ray detection device of the present invention; Figure 4This is a schematic structural diagram of the packaging shell of the portable low-energy ray detection device of the present invention; Figure 5 Schematic diagram of the relationship between the various components of the portable low-energy ray detection device of the present invention; Figure 6 Energy distribution diagram of low-energy X-rays or gamma rays to verify the feasibility of the fiber optic probe structure design; Figure 7 A test model for low-energy X-ray or gamma-ray penetration performance to verify the feasibility of the fiber optic probe structure design; Figure 8 In order to verify the feasibility of the optical fiber probe structure design, Cs3Cu2I5:Mn 2+ Simulation calculation diagram of 15% scintillator material absorption efficiency; Figure 9 In order to verify the feasibility of the optical fiber probe structure design, Cs3Cu2I5:Mn 2+ Schematic diagram of the results of 15% scintillator material absorbing low-energy rays; Figure 10 To verify the feasibility of the fiber optic probe structure design, the XRD pattern of 15% Mn doped powder; Figure 11 In order to verify the feasibility of the optical fiber probe structure design, Cs3Cu2I5:Mn 2+ Radioluminescence spectrum of 15% sample; Figure 12 In order to verify the feasibility of the optical fiber probe structure design, Cs3Cu2I5:Mn 2+ PL and PLE spectra of 15% sample; Figure 13 In order to verify the feasibility of the fiber optic probe structure design, Cs3Cu2I5:Mn 2+ 15% RL stability diagram; Figure 14 This is a circuit connection diagram of the alarm circuit control module of the present invention. DETAILED DESCRIPTION

[0025] The present invention will be described in further detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0026] It should be understood that terms such as “having”, “including” and “comprising” used herein do not preclude the existence or addition of one or more other elements or combinations thereof.

[0027] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the reagents and materials are commercially available unless otherwise specified. In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "set" should be understood in a broad sense, for example, they can be fixedly connected or set, or detachably connected or set, or integrally connected or set. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The orientations or positional relationships indicated by the terms "transverse", "longitudinal", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0028] like Figure 1-Figure 5 As shown, a portable low-energy ray detection device provided by an embodiment of the present invention includes: an optical fiber probe module, which includes: an optical fiber core; a cylindrical aluminum foil mold, which is a hollow structure, the optical fiber core is inserted into the cylindrical aluminum foil mold, and an annular cavity is formed between the optical fiber core and the cylindrical aluminum foil mold; a composite scintillator layer, the composite scintillator layer is Cs3Cu2I5:Mn 2+ A mixture of 15% scintillator material and UV glue is injected into the annular cavity and cured to form the composite scintillator layer, which is used to absorb low-energy X-rays or gamma rays and emit fluorescence outward, and the cylindrical aluminum foil mold serves as a reflective layer to reflect the stimulated fluorescence; a 3D printed fiber optic cap, a 3D printed fiber optic cap, and the fiber optic probe module is fixedly arranged inside the 3D printed fiber optic cap to form a complete fiber optic probe; a photocell, whose photosensitive surface is coupled with the output end of the fiber optic probe module and converts the fluorescence signal into an electrical signal; an alarm circuit control module, which includes a transistor control circuit and a light emitting diode connected to the transistor control circuit, the photocell is connected to the transistor control circuit, and when the transistor control circuit is in a saturated conduction state, the light emitting diode emits light.

[0029] Specifically, the wall thickness of the 3D printed fiber cap is 1 mm, the inner diameter is 3.5 mm, the outer diameter is 4.5 mm, and the length is 18 mm; the material used for the 3D printed fiber cap is nylon PA12; the wall thickness of the cylindrical aluminum foil mold is 50 μm-0.1 mm, the length is 17.5 mm, and the inner diameter is 3 mm; the minimum energy measurement threshold of low-energy X-rays or gamma rays is 20 KeV; the photocell is a 2DU3 silicon photocell. The Cs3Cu2I5:Mn 2+ The emission wavelength range of the 15% scintillator material is 400-650nm; the optical fiber core is a PMMA optical fiber core with a diameter of 1.985mm, and the applicable wavelength range of the optical fiber core is 400-700nm; the 3D printed optical fiber cap is hollow cylindrical, with one end being tapered and the other end being open.

[0030] In the above embodiment, the fiber optic probe module includes an optical fiber core, a cylindrical aluminum foil mold, and a composite scintillator layer. The 3D printed fiber cap is used to encapsulate the optical fiber probe module. In the specific configuration, for example, the optical fiber core can be made of PMMA, preferably with a diameter of 1.985 mm and an applicable wavelength range of 400-700 nm; the wall thickness of the cylindrical aluminum foil mold can be selected to be 50 μm, 0.08 mm, or 0.1 mm, with an inner diameter of 3 mm and a length of 17.5 mm; the composite scintillator layer is made of Cs3Cu2I5:Mn 2+ 15% scintillator material is mixed with UV glue and injected into the annular cavity and cured to form an emission wavelength range of 400-650nm; the 3D printed optical fiber cap can be made of nylon PA12 material, with a wall thickness of preferably 1mm, an inner diameter of preferably 3.5mm, an outer diameter of preferably 4.5mm, and a length of preferably 18mm.

[0031] After the optical fiber core is inserted into the cylindrical aluminum foil mold, an annular cavity is formed between the two. 2+After a 15% scintillator material and UV adhesive mixture is injected into the annular cavity and cured to form the composite scintillator layer, the cylindrical aluminum foil mold is not removed. Instead, it serves as a reflective layer, reflecting the stimulated fluorescence back into the optical fiber core, thereby improving fluorescence coupling efficiency. The 3D-printed fiber cap is a hollow cylinder with a tapered end and an open end. The fiber optic probe module is secured within it. The tapered end of the 3D-printed fiber cap protects the optical fiber core, while the open end is used for coupling with the photocell. The 3D-printed fiber cap is made of nylon PA12, which also enhances the waterproofness and mechanical stability of the optical fiber probe. Low-energy X-rays or gamma rays enter the composite scintillator layer, where they are absorbed and stimulate fluorescence. This fluorescence is reflected by the cylindrical aluminum foil mold and transmitted from the optical fiber core to the output end. Therefore, the optical fiber probe can effectively detect low-energy radiation and convert it into fluorescence. The cylindrical aluminum foil mold's reflective layer improves fluorescence collection efficiency, while the 3D-printed fiber cap provides stable mechanical protection and optical alignment.

[0032] The photocell can be a 2DU3 silicon photocell, with its photosensitizing surface directly coupled to the output end of the fiber optic probe. The photocell's response wavelength range covers 400-700 nm, matching the emission wavelength of the composite scintillator layer. The photocell converts the received fluorescence signal into an electrical signal, outputting a current or voltage signal to the subsequent circuitry. The photocell's mounting position closely matches the open end of the 3D-printed fiber cap, ensuring optical alignment and minimizing signal loss. The photocell operates as follows: the fluorescence signal is transmitted through the fiber core to the photosensitive surface of the photocell, which generates a corresponding electrical signal based on the light intensity. The magnitude of the electrical signal is proportional to the intensity of the incident radiation, enabling quantitative detection of radiation intensity. The photocell's output can directly drive the subsequent alarm circuit control module. This design achieves efficient conversion of optical to electrical signals. The choice of photocell ensures a wavelength match with the scintillator emission, improving detection sensitivity. The compact mounting of the photocell reduces signal attenuation, facilitating integration into portable devices.

[0033] The alarm circuit control module includes a transistor control circuit and a light-emitting diode. The transistor control circuit is connected to the output end of the photocell. When the electrical signal output by the photocell reaches the set threshold, the transistor control circuit enters a saturated conduction state and drives the light-emitting diode to emit light. The conduction threshold of the light-emitting diode can be set to an electrical signal value corresponding to 20KeV. The assembly position of the alarm circuit control module is located after the photocell. The transistor control circuit and the light-emitting diode can be installed on a circuit board and connected to the photocell via wires. The working process is: when the electrical signal output by the photocell exceeds the conduction threshold, the transistor control circuit is turned on and the light-emitting diode lights up, indicating that low-energy rays are detected. If the electrical signal is lower than the conduction threshold, the transistor control circuit is cut off and the light-emitting diode remains off.

[0034] This alarm circuit control module implements a real-time alarm function for radiation detection. It features a simple and reliable circuit structure, low power consumption, and is suitable for use in portable devices. The intuitive LED prompts allow users to quickly determine the detection results.

[0035] In one embodiment, Figure 14 As shown, the triode control circuit specifically includes: NPN transistor, whose emitter e2 is connected to the positive electrode of the light emitting diode, collector c2 is connected to the positive electrode of the power supply through the adjustable resistor R5, and the negative electrode of the light emitting diode is grounded; A PNP transistor, whose emitter e1 is connected to the positive electrode of the power supply through an adjustable resistor R2, and whose collector c1 is connected to both the base b2 of the NPN transistor and one end of the adjustable resistor R1, and the other end of the adjustable resistor R1 is grounded; Among them, the positive electrode of the photocell is connected to the base b1 of the PNP transistor, the negative electrode of the photocell is connected to one end of the adjustable resistor R3 used to protect the photocell, the other end of the adjustable resistor R3 is grounded, and the PNP transistor and the NPN transistor perform cascade amplification on the electrical signal output by the photocell; a control switch is also arranged between the positive electrode of the power supply and the adjustable resistor R2.

[0036] Specifically, the emitter current e2 of the NPN transistor is the current i of the light emitting diode. e2 , the expression is: + , Among them, i e1 is the emitter e1 current of the PNP transistor, i b1 is the base b1 current of the PNP transistor, V c1 is the collector c1 voltage of the PNP transistor, V1 is the power supply voltage, and the photosensitivity of the transistor control circuit is adjusted by adjusting the resistance value of the adjustable resistor R1.

[0037] Furthermore, the resistance range of the adjustable resistor R1 is set to 300Ω to 20kΩ to detect low-energy X-rays or gamma rays of different intensities; and the power source is a lithium battery.

[0038] In the above embodiment, the transistor control circuit includes a PNP transistor, an NPN transistor, an adjustable resistor R1, an adjustable resistor R2, an adjustable resistor R3, an adjustable resistor R5, a light emitting diode, a photocell and a control switch. For example, the PNP transistor can be a 2N3906 type PNP transistor, and the NPN transistor can be an S8050 type NPN transistor; the photocell is a 2DU3 type photocell, and its output current is proportional to the incident light intensity; the light emitting diode is an F3 type light emitting diode, and the power supply can be a 14500 type lithium battery with a diameter of 14mm, a height of 50mm, a battery voltage of 3.7V, and a nominal capacity of 1600mAh. The control switch can be a push button switch. According to the circuit diagram of the connection relationship between the transistor control circuit, the light emitting diode and the adjustable resistor, when the transistor control circuit is in the on state, the emitter e2 current of the NPN transistor, that is, the current i of the light emitting diode, is obtained. e2 The expression of + (1) Since the PNP transistor is in saturation conduction state, V c1 、i e1 、i b1 The value does not change significantly with the resistance of the adjustable resistor R1. It can be regarded as a constant value within a certain range of the resistance of the adjustable resistor R1. From formula (1), it can be concluded that i e2 As the resistance of adjustable resistor R1 increases, that is, the greater the resistance of adjustable resistor R1, under the same conditions, the lower the light intensity required by the circuit to cause the light-emitting diode to emit light. This means that by adjusting the resistance of R1, the photosensitivity of the circuit can be controlled, facilitating the subsequent quantitative control of the sensitivity of the detection device based on the type of radiation source. For example, in a specific setting, the resistance of adjustable resistor R1 is 1kΩ, the resistance of adjustable resistor R2 is 100Ω, the resistance of adjustable resistor R3 is 3kΩ, and the resistance of adjustable resistor R5 is 47Ω. H1 is an expandable power connector that can be connected to an external power supply.

[0039] The alarm circuit control module operates as follows: the photocell detects a fluorescent signal and outputs an electrical signal. A PNP transistor performs primary amplification, and an NPN transistor further amplifies the signal and drives the light-emitting diode. Adjusting the value of adjustable resistor R1 changes the circuit's trigger threshold, adapting it to the needs of detecting different radiation intensities.

[0040] The triode control circuit uses a cascade amplification design to improve signal detection sensitivity. The introduction of an adjustable resistor allows the circuit to flexibly adapt to input signals of varying strengths. The on / off status of the LED directly reflects the X-ray detection results, allowing users to quickly make judgments.

[0041] The transistor control circuit is assembled after the photocell output. All components can be soldered onto a small PCB and connected via wires. For example, the PCB is 1.4859 cm wide and 3.6195 cm long, making it suitable for portable designs. The photocell output is connected to the base of the PNP transistor, b1, via a control switch, ensuring controllable signal on and off. Adjustable resistors R1, R2, R3, and R5 are standard adjustable resistors for easy field adjustment. The LED can be mounted in a prominent position on the package for easy observation.

[0042] Functional testing of the transistor control circuit can be performed by simulating the output signal of a photocell. For example, a variable resistor or signal generator can be used to simulate electrical signals of varying intensities and observe the response of the light-emitting diode (LED). Experimental subjects can include low-energy X-ray or gamma-ray sources of varying intensities. By comparing the circuit output with the actual radiation intensity, the circuit's reliability and sensitivity can be verified. This transistor control circuit can stably amplify the weak signal output by the photocell and provide a visual alarm indication through the LED. The adjustable resistor design allows the circuit to adapt to different application scenarios, enhancing the versatility and practicality of the detection equipment.

[0043] In one specific embodiment, it also includes a 3D printed coupling mold, which is a solid rectangular structure, and a through cylindrical hole is set along the long axis of the rectangular structure, and the aperture of the cylindrical hole is adapted to the outer diameter of the 3D printed optical fiber cap; a groove is also provided at one end of the rectangular structure, and the size of the groove is adapted to the size of the photocell, and the groove is connected to the cylindrical hole, the optical fiber probe is inserted into the cylindrical hole and fixed, and the output end of the optical fiber probe is facing the groove; the photocell is fixed in the groove, so that the photosensitive surface of the photocell is in contact with the output end of the optical fiber probe.

[0044] In the above embodiment, the 3D printed coupling mold is 3D printed using Photon Mono and is a solid rectangular structure with a through cylindrical hole in the long axis direction. An assembly gap of 0.1mm-0.3mm can be retained between the cylindrical hole and the outer diameter of the 3D printed fiber optic cap to facilitate insertion and fixation. The aperture of the cylindrical hole can be set to 4.6-4.9mm, which matches the outer diameter of the 3D printed fiber optic cap. Since the size of the 2DU3 type silicon photovoltaic cell after packaging is 8×6×2mm, the size of the groove at one end of the rectangular structure can be designed to be 10mm×8mm×3mm to accommodate and fix the photovoltaic cell. The 3D printed coupling mold material can be selected from common 3D printing materials such as nylon PA12, ABS or PLA.

[0045] The 3D-printed coupling mold secures the 3D-printed fiber cap via a cylindrical hole and the photocell via a groove. During assembly, the 3D-printed fiber cap is inserted into the cylindrical hole and secured with UV adhesive, ensuring the output end of the fiber probe faces the groove. Once the photocell is inserted into the groove, its photosensitive surface aligns tightly with the output end of the fiber probe. The rectangular structure of the 3D-printed coupling mold provides mechanical protection for the internal components and facilitates assembly into the detection device's housing.

[0046] This design achieves precise alignment between the fiber optic probe and the photocell, ensuring efficient transmission of optical signals. The integrated structure of the 3D-printed coupling mold simplifies the assembly process and improves device reliability.

[0047] During operation, the fluorescence signal output by the fiber optic probe is directly incident on the photosensitive surface of the photocell through the output end. The precise structure of the 3D-printed coupling mold ensures that the parallelism and spacing between the two optical end faces are controlled within the optimal range. This coupling method reduces light signal loss during transmission and improves detection sensitivity. The standardized design of the 3D-printed coupling mold facilitates mass production and maintenance and replacement.

[0048] During testing, a standard light source is used to illuminate the fiber probe, and the photocell output current is measured to verify coupling efficiency. Signal strength under different assembly pressures can be compared to determine the optimal installation method. Ambient light interference testing can be performed by adding a light shield to the exterior of the 3D-printed coupling mold. Long-term stability testing simulates actual operating conditions and observes signal drift.

[0049] Testing has shown that the 3D-printed coupling mold can maintain stable optical alignment and operate reliably under conditions of vibration and temperature fluctuations. Its modular design facilitates integration with other components, making it suitable for the manufacture of portable detection equipment.

[0050] In one embodiment, the Cs3Cu2I5:Mn 2+ In the mixture of 15% scintillator material and UV glue, Cs3Cu2I5:Mn 2+ The mass ratio of 15% scintillator material and UV glue is 0.7-1.3:1; the Cs3Cu2I5:Mn 2+ The preparation method of the mixture of 15% scintillator material and UV glue comprises the following steps: a. weighing Cs3Cu2I5:Mn 2+ 15% scintillator material powder is poured into UV glue; b. Use glass rod to stir thoroughly to make Cs3Cu2I5:Mn 2+ 15% scintillator material powder is evenly dispersed in UV glue; c. Use a 1ml syringe with a 27G ultra-fine dispensing needle to dissolve Cs3Cu2I5:Mn 2+15% scintillator material and UV glue mixture is injected into the annular cavity; d. Injection and curing are carried out in 3-4 stages, and after each injection, 220-260 nm UV light is irradiated for 30 s to ensure that Cs3Cu2I5:Mn 2+ The mixture of 15% scintillator material and UV glue is completely cured.

[0051] In the above embodiment, Cs3Cu2I5:Mn 2+ The mass ratio of 15% scintillator material to UV glue can be selected as 0.7:1, 1:1 or 1.3:1. 2+ The radioluminescence properties of 15% scintillator materials are easily affected by water molecules. Therefore, the solvent used for the scintillator material should be water-free, low-viscosity, and easy to cure. Henkel Loctite AA3311 is a preferred UV adhesive. Henkel Loctite AA3311 offers advantages such as a single component and low viscosity, and it cures quickly under sufficiently intense UV light (220-260 nm). A glass beaker or plastic centrifuge tube can be used as the mixing container.

[0052] During preparation, weigh the Cs3Cu2I5:Mn 2+ Slowly add 15% scintillator material powder to the UV adhesive and stir at 200-300 rpm for 10-15 minutes using a glass rod or paddle. Heat to 40-50°C during stirring to reduce viscosity. After mixing thoroughly, let stand for 5 minutes to defoam, resulting in a flowable, homogeneous mixture. This mixture maintains a working temperature of 30-60 minutes at 25°C, facilitating subsequent adhesive injection.

[0053] This ratio ensures that Cs3Cu2I5:Mn 2+ 15% scintillator material is evenly distributed in the solidified matrix while maintaining appropriate fluidity. UV glue as a carrier ensures mechanical strength without affecting the optical properties of the scintillator.

[0054] The syringe can be a 1ml glass syringe with a 27G dispensing needle. The injection of the annular cavity is completed in 3-4 stages. The UV curing lamp can be an LED point light source or a surface light source. Immediately after each injection, the UV light is irradiated, the irradiation distance is maintained at 5-10cm, and the irradiation time is 30-60 seconds. This process achieves uniform filling and complete curing of the composite scintillator layer. The staged operation avoids the generation of bubbles and ensures the Cs3Cu2I5:Mn 2+ The 15% scintillator material fits tightly into the cylindrical aluminum foil mold. The UV curing method is highly efficient and does not affect the luminous properties of the scintillator.

[0055] The composite scintillator layer produced by this preparation method exhibits excellent optical properties and mechanical stability. Precisely controlled formulation and process ensure consistency and reliability of the detection device, making it suitable for mass production. The cured scintillator layer securely bonds to the optical fiber core, ensuring long-term stable operation.

[0056] In one specific embodiment, it also includes a packaging shell, in which the optical fiber probe, the photocell, the alarm circuit control module and the 3D printed coupling mold are all packaged. One end of the packaging shell is conical, and the light-emitting diode passes through the shell wall of the packaging shell and is fixedly set on the packaging shell; the control switch passes through the shell wall of the packaging shell and is fixedly set on the packaging shell.

[0057] In the above embodiment, the package shell is printed using a Photon Mono light-curing 3D printer. For example, the package shell can be made of ABS or polycarbonate material, with a wall thickness of 1.2-2.0 mm and an overall length of 60-90 mm. The cone angle of the tapered end can be set to 30-45 degrees to facilitate detection operations. Positioning slots and fixing columns can be provided inside the package shell for precise installation of various functional modules. The mounting hole diameter of the light-emitting diode and control switch can be designed to be 3-5 mm to match the standard component size. The package shell can be designed as a split structure and fixed by screws or clips.

[0058] During assembly, the fiber optic probe, photocell, alarm circuit control module, and 3D-printed coupling mold are installed in sequence. The LED and control switch are inserted through the reserved holes in the package housing and then secured and sealed with epoxy resin. Internal wiring is neatly arranged in cable ducts to avoid interference. Finally, the housing is closed and tightened to ensure a secure overall structure. A wear-resistant rubber sleeve can be added to the tapered end to protect the fiber optic probe.

[0059] The package design provides reliable mechanical protection and electromagnetic shielding for the internal components. The modular assembly method simplifies the production process and facilitates quick disassembly and assembly for maintenance. The conical structure of the package shell optimizes operability during detection.

[0060] Another embodiment of the present invention further provides a method for preparing a portable low-energy ray detection device, comprising the following steps: S1. Obtain Cs3Cu2I5:Mn 2+ 15% scintillator material, and Cs3Cu2I5:Mn 2+ 15% is mixed with UV glue as scintillator material to form Cs3Cu2I5:Mn 2+ 15% scintillator material and UV glue mixture; S2, insert the optical fiber core into the cylindrical aluminum foil mold, and Cs3Cu2I5:Mn2+ A mixture of 15% scintillator material and UV glue is injected into the annular cavity between the optical fiber core and the cylindrical aluminum foil mold. The injection and curing are performed in stages to obtain an optical fiber probe module. During the glue injection process, the optical fiber core must be located at the center of the cylindrical aluminum foil mold. S3. Use a light-curing 3D printer to obtain a 3D-printed fiber cap, inject UV glue into the inner side wall of the 3D-printed fiber cap, insert the fiber probe module into the 3D-printed fiber cap, and use UV glue to encapsulate it to obtain a plastic fiber probe; S4. Use a photocell as a photoelectric conversion device to convert the optical signal into an electrical signal; use a 3D printer to obtain a 3D printed coupling mold, fix the photocell in a groove at one end of the 3D printed coupling mold using UV glue, insert the other end into the output end of the plastic optical fiber probe, and make the photosensitive surface of the photocell fit the output end of the optical fiber probe module; S5. Make a PCB circuit board of the alarm circuit control module; S6. Use a 3D printer to obtain a packaging shell, and package the optical fiber probe, the photocell, the 3D printed coupling mold, and the PCB circuit board in the packaging shell.

[0061] In the above embodiment, through the integrated design of the optical fiber probe, photocell and alarm circuit control module, miniaturized, low-cost and high-sensitivity low-energy ray detection is achieved, which solves the problems of traditional X-ray or gamma-ray detectors being large in size, high in cost, complex in operation and insufficient in sensitivity to low-energy ray detection. The feasibility of the portable low-energy ray detection device is specifically verified below.

[0062] First, in order to verify the feasibility of the fiber optic probe structure design, this embodiment uses simulation software to simulate the penetration performance of low-energy X-rays or gamma rays. The Monte Carlo method is the most effective and commonly used tool to study particle transport problems, and is widely used in the transport problems of particles such as neutrons, photons, and electrons. MCNP (Monte Carlo N-ParticleTransport code) is a set of Monte Carlo simulation calculation programs for calculating particle transport processes. This embodiment uses the Monte Carlo simulation software MCNP6 to record the number of photons and energy distribution of 0.05-0.5MeV low-energy X-rays or gamma rays after penetrating a 1mm thick 3D printed fiber cap and a 0.1mm thick cylindrical aluminum foil mold reflective layer through an F1 counting card. The energy distribution of low-energy X-rays or gamma rays is as follows: Figure 6 As shown in Figure 2, low-energy rays of 0.05-0.3 MeV account for the majority. The simulation calculation model is as follows Figure 7As shown, the low-energy ray point source is 2 cm away from the central axis of the fiber optic probe module, the particle number is set to 500,000, the 3D printed fiber optic cap is made of PA12, and the cylindrical aluminum foil mold reflective layer both adopt a cylindrical structure with a length of 1.5 cm. A recording surface is set inside the cylindrical aluminum foil mold reflective layer, and the recording surface is filled with lead to prevent the recording surface from repeatedly recording transmitted photons.

[0063] Table 1 shows the probability of recording photons on the recording surface using the above model, with no energy cutoff (photons with energies below the energy cutoff are not counted) and with energy cutoffs of 0.05 MeV, 0.1 MeV, 0.15 MeV, 0.2 MeV, 0.25 MeV, and 0.3 MeV. The probability of photon collection on the recording surface is greater than 1 when no energy cutoff is set and when the energy cutoff is set at 0.05 MeV. This is because the lead within the recording surface does not fully absorb the higher-energy photons of the low-energy radiation, resulting in a small amount of photon overcounting. As can be seen in Table 1, the energy transmission ratios for each interval are essentially the same as those for the low-energy point source. MCNP simulations ultimately concluded that the 1 mm thick 3D-printed fiber cap and the 0.1 mm thick cylindrical aluminum foil mold reflective layer have minimal and negligible effects on the transmission of low-energy X-rays or gamma rays.

[0064] Table 1 MCNP6 simulation results Energy cutoff point (MeV) 0 0.05 0.1 0.15 0.2 0.25 0.3 Probability P 1.06185 1.05994 0.69606 0.49639 0.29747 0.19807 0.09912 Scintillators are described below. Scintillators are optoelectronic materials that absorb energy from high-energy particles such as X-rays, gamma rays, alpha rays, and beta rays and emit ultraviolet (UV) or visible light (VIS). They are widely used in environmental monitoring, medical X-ray or gamma ray detection and protection, and high-energy physics experiments. Scintillator materials can be divided into organic and inorganic scintillators. Organic scintillators have higher fluorescence efficiency but are generally smaller in size. Inorganic scintillators can be categorized into different forms, such as scintillator crystals, scintillator ceramics, phosphors, and scintillator films, depending on the application conditions and fields. The scintillation process of inorganic scintillators is primarily divided into three stages: conversion, migration, and luminescence. The portable low-energy radiation detection device designed in this embodiment is primarily used to detect low-energy X-rays or gamma rays in medical environments. The low-energy radiation energy distribution ranges primarily from 0.05 to 0.3 MeV, with the photoelectric effect playing a dominant role. The ideal properties of scintillators vary depending on the application environment. When used to detect low-energy X-rays or gamma rays in medical radiation departments, where low-energy X-rays or gamma rays may be present, the performance requirements for the scintillator include light output efficiency, decay time, emission wavelength, and chemical stability.

[0065] The portable low-energy ray detection device designed in this embodiment uses a new metal halide scintillator material Cs3Cu2I5:Mn 2+15%, purchased from Professor Li Xiaoming's research group at Nanjing University of Science and Technology. Cs3Cu2I5:Mn 2+ After 15% scintillator material was washed and purified by n-butanol, the air stability was greatly improved. 2+ 15% scintillator material powder did not deliquesce or agglomerate after being placed in air environment for 2 months. 2+ The 15% scintillator material has good irradiation stability and can maintain more than 95% of the initial radioluminescence intensity (RL) after receiving a total radiation dose of 2500Gy at 25°C. 2+ The emission wavelength range of the 15% scintillator material (400-650nm) matches the application wavelength range of the optical fiber core (400-700nm), which can effectively reduce the transmission loss of fluorescence in the optical fiber.

[0066] In the acquisition of Cs3Cu2I5:Mn 2+ After 15% of the scintillator material sample was collected, a series of characterization tests were conducted on its optical properties and radioluminescence properties. First, the MCNP6 program was used to simulate and calculate its absorption efficiency of low-energy X-rays or gamma rays. The energy distribution of the low-energy X-ray or gamma ray source is as follows: Figure 6 As shown, the simulation calculation graph is as follows Figure 8 As shown. By changing the energy cutoff point, the simulation calculation results are as follows: when the energy cutoff point is set to 0.05MeV, the probability of the recording surface remembering a photon is 0.532152; when the energy cutoff point is set to 0.1MeV, the probability of the recording surface remembering a photon is 0.480854; when the energy cutoff point is set to 0.2MeV, the probability of the recording surface remembering a photon is 0.257376; when the energy cutoff point is set to 0.3MeV, the probability of the recording surface remembering a photon is 0.090901. The probability of the recording surface remembering photons in each energy interval is plotted and compared with the probability of photons in each energy interval of low-energy X-ray or gamma-ray sources. The results are shown as follows Figure 9 shown.

[0067] According to the simulation results, it can be concluded that: Cs3Cu2I5:Mn 2+ The absorption efficiency of 15% scintillator for low energy X-rays or gamma rays (0.05-0.5MeV) is about 45%, among which the absorption efficiency for low energy X-rays or gamma rays with energy distribution of 0.05-0.1MeV is the highest, reaching about 82%, and the absorption efficiency for low energy X-rays or gamma rays with energy distribution of 0.3-0.5MeV is the lowest, only about 9%. 2+ The 15% scintillator has a higher absorption efficiency for low-energy X-rays or gamma rays below 0.2 MeV, and a lower absorption efficiency for X-rays or gamma rays above 0.3 MeV.

[0068] The Cs3Cu2I5:Mn 2+ After the absorption efficiency of the scintillator material for low-energy X-rays or gamma rays was determined by 15%, a series of tests were conducted on the optical properties of the material. First, the X-ray diffraction spectrum of the sample was measured using a powder X-ray diffractometer produced by Bruker, Germany. The operating voltage was 30KV, the current was 20mA, the scanning angle was 5° / min, the scanning step was 0.02 degrees, and the scanning range was 20-60°. The measured XRD pattern was compared with the standard card of the Cs3Cu2I5 crystal structure obtained from the crystallography OpenDatabase, and the graph was obtained as shown below. Figure 10 As shown. Figure 10 It can be seen that the tested diffraction curve is in good agreement with the standard card PDF#45-0077 curve, indicating that the synthesized new metal halide scintillator, namely Cs3Cu2I5:Mn 2+ 15% of the scintillator material has a pure phase.

[0069] Secondly, Cs3Cu2I5:Mn 2+ A 15% scintillator material sample was placed in a fixed steel container and placed in an integrating sphere 1 cm away from an X-ray source to test its radioluminescence performance. The X-ray source was generated by a commercial Amptek mini-x tube, operating at 60 kV and 50 μA. The data were recorded using a fiber optic spectrometer QE65PRO. The experimental data were plotted using Origin software. The results are shown in the figure below. Figure 11 In order to compare the Cs3Cu2I5:Mn 2+ The radioluminescence performance of 15% scintillator material samples was tested under the same test conditions as the radioluminescence (RL) spectrum of CsI(Tl) scintillator. Figure 11 As can be seen in the image, the 15% Mn-doped Cs3Cu2I5 scintillator exhibits ultra-high radioluminescence intensity, with the strongest emission wavelength at 564nm. Compared to CsI(Tl) scintillator, this sample has a narrower radioluminescence spectrum peak, which helps improve the detector's energy resolution. The sample is estimated to have an ultra-high light yield of approximately 67,000 ph. / MeV at 564nm, far exceeding that of traditional metal halide scintillators such as NaI(Tl) and CsI(Tl).

[0070] Finally, the fluorescence spectrum and chemical stability of the sample are tested. Fluorescence spectra can be divided into excitation (ex) and emission (em) spectra, which are widely used in the characterization of the optical properties of luminescent materials. When the excitation wavelength is constant, the spectrum measured by changing the emission wavelength is the emission spectrum, which reflects the change in the fluorescence intensity of the material under different emission wavelengths, and the optimal excitation wavelength of the sample can be determined through this spectrum; when the emission wavelength is constant, the spectrum measured by changing the excitation wavelength is the excitation spectrum, which describes the change in the fluorescence intensity of the material under different excitation wavelengths, and the optimal emission wavelength of the sample can be determined through this spectrum. In this embodiment, a Varian Cary Eclipse fluorescence spectrometer is used to measure the excitation spectrum (PLE) and fluorescence spectrum (PL) of the sample. The excitation wavelengths (ex) used in testing the emission spectrum are 316nm, 379nm, and 482nm, respectively, and the test range is 300-700nm; the emission wavelength used in testing the excitation spectrum is 564nm (em=564nm). The test results are as follows Figure 12 As shown: from Figure 12 As can be seen, the excitation spectrum detected at 564 nm displays three bands, primarily consisting of a strong intrinsic absorption band with a luminescence center at 316 nm, and weaker absorption bands at 379 nm and 482 nm. Under 316 nm excitation, the PL spectrum consists of two luminescence centers located at ~440 nm and ~560 nm, respectively. However, when the 15% Mn-doped powder is excited at 379 nm and 482 nm, the PL spectrum exhibits only a luminescence center at ~560 nm, and its luminescence intensity is significantly lower than that obtained with 316 nm excitation. Therefore, it can be concluded that this sample emits bright yellow light when irradiated with low-energy X-rays, gamma rays, or ultraviolet light. This makes it suitable not only for detecting low-energy X-rays and gamma rays that may be present in radiation-departmental areas such as X-ray and CT scan rooms, but also for detecting UV leaks in hospitals to ensure personnel safety.

[0071] In order to further verify the Cs3Cu2I5:Mn 2+ The feasibility of 15% scintillator materials was studied. 2+ The air stability and irradiation stability of 15% scintillator material. Without any protective measures, the material was placed in the air for 60 days and the color was still light yellow and there was no agglomeration, indicating that the Cs3Cu2I5:Mn 2+ The 15% scintillator material has a high air stability. Secondly, we tested the X-ray excitation spectrum of the sample after 60 days of storage under ambient conditions and compared it with the X-ray excitation spectrum of the initial sample. The results are as follows Figure 13 As shown. Figure 13It can be seen that after 60 days of storage under ambient conditions, the Cs3Cu2I5:Mn 2+ The luminescence intensity of the 15% scintillator material showed a significant attenuation, and at a wavelength of 650nm, its maximum luminescence intensity was about 81% of the initial maximum luminescence intensity. 2+ 15% scintillator material was placed in a 70℃ drying oven and dried for two hours. The maximum luminous intensity was measured to be about 92% of the initial maximum luminous intensity. 2+ 15% scintillator material has high irradiation stability. When making fiber optic probes in the future, the Cs3Cu2I5:Mn 2+ 15% of the scintillator material is placed in a drying oven and dried for a period of time to reduce the influence of moisture on the radioluminescence performance of the material.

[0072] After encapsulating the fiber optic probe module with a 3D-printed fiber cap, the probe's waterproofness and stability were tested. After being submerged in water for 5 minutes, no moisture entered the probe. Afterward, it was dropped from a height of 1 meter, and the structure remained intact. These tests demonstrate that the fiber optic probe exhibits excellent waterproofness and mechanical stability.

[0073] Second, regarding the simulation design and testing of the alarm circuit control module.

[0074] This embodiment uses Multisim software to design the alarm circuit control module of the detection device. Multisim is a circuit simulation software developed by National Instruments (NI) in the United States. It is widely used in education, electrical engineering, electronic engineering and other fields. It provides an intuitive graphical interface.

[0075] The alarm circuit control module consists of a 14500 lithium battery, an S8050 NPN transistor, a 2N3906 PNP transistor, a 2DU3 photocell, an F3 light-emitting diode, and several adjustable resistors. Since Multisim software is developed by National Instruments, the main database only contains transistors. Since the 2N2904 PNP transistor and the 2N3906 PNP transistor have equivalent performance, the 2N2904 transistor was used instead of the 2N3906 transistor for simulation testing. Similarly, the 2N2222 transistor was used instead of the S8050 transistor for simulation testing. Since the 2DU3 photocell is not included in the main database, the characteristics of the photocell are that it can function as an electronic device when unlit; when illuminated, it can function as either a voltage source or a current source. In the absence of light, a multimeter measured the internal resistance of the 2DU3 silicon photocell to be as high as 100MΩ, making it virtually non-conductive. When placed indoors, the voltage was measured to be between 0.1-0.2V, with a current of approximately 0.05mA. Using a strong flashlight to illuminate the cell, the maximum voltage was measured to be approximately 0.55V, with a maximum current of approximately 0.6mA. To improve the sensitivity of the portable detection device designed in this embodiment to low-energy X-rays or gamma rays, a 0.1V voltage is generated by the photocell. A voltage source V1 is used in its place, and an adjustable current-limiting resistor R3 is provided to protect the cell from damage due to excessive power.

[0076] Through simulation, it can be seen that the alarm circuit control module adopts PNP and NPN transistor cascade amplification control. The circuit structure is simple, which is convenient for adjusting the photosensitivity of the circuit. At the same time, it solves the problem of large leakage current of the transistor, and meets the performance requirements of the alarm circuit of the detection device.

[0077] Based on the simulation results obtained using Multisim software, a simulation circuit was built on a breadboard to perform performance testing while maintaining a certain ambient light level.

[0078] Under constant ambient lighting conditions, a flashlight is used as an external light source to illuminate the photocell's photosensitive surface, ensuring a constant divergence angle and radiating light vertically downward from the photocell's photosensitive surface. For a constant flashlight power, the intensity of the light received by the photocell's photosensitive surface is inversely proportional to the distance from the flashlight, and therefore inversely proportional to the radius of the illumination aperture. Test results show that when the adjustable resistor R1 is set to 300Ω, the LED reaches peak luminous intensity at an aperture radius of 3.25cm. Gradually increasing the value of the adjustable resistor R1 increases the aperture radius just at the point where the LED reaches peak luminous intensity, decreasing the required illumination intensity. When the adjustable resistor R1 is set to 20kΩ, the photocell reaches peak luminous intensity under ambient light without requiring an external light source. Actual testing confirms that the test results are generally consistent with those obtained from simulations.

[0079] 3. After coupling the optical fiber probe and the photocell using a 3D printed coupling mold, the detection device is tested before being encapsulated using a packaging shell.

[0080] First, the detection device's sensitivity to low-energy X-rays was tested. The X-ray source was a commercial Amptek mini-x tube. The fiber optic probe module was secured to the X-ray tube orifice using tape. The operating current was set to 60 μA, and the operating voltages were set to 50, 40, 30, and 20 kV. To minimize the influence of ambient light on the test results, the room lights were turned off and the device was left alone for a period of observation before testing. The test results showed that the LED brightness reached its maximum at a low-energy X-ray energy of 50 keV, but still did not reach peak intensity. At a low-energy X-ray energy of 40 keV, the LED emitted stable light, though its brightness was slightly reduced compared to that at 50 keV. At a low-energy X-ray energy of 30 keV, the LED emitted unstable light and a dim brightness. At a low-energy X-ray energy of 20 keV, the LED emitted almost no light. Therefore, it can be concluded that the detection device can detect low-energy X-rays above 20 keV, and that the LED brightness gradually increases with increasing low-energy X-ray energy.

[0081] Secondly, the detection sensitivity of the detection device for low-energy gamma rays was tested, where the low-energy gamma rays were generated by thorium oxide (ThO2) powder. Natural thorium is mainly composed of thorium-232 ( 232 Th), with a half-life of about 14 billion years. After a series of α and β decays, it turns into multiple radioactive daughters and eventually stabilizes to lead-208 ( 208During the decay process of thorium oxide (Pb), certain daughters (such as thallium-208, bismuth-212, and lead-212) emit gamma rays. The characteristic gamma-ray energy emitted by thorium oxide primarily consists of low-intensity (e.g., 238.6 KeV, 300.1 KeV, and 511.0 KeV), medium-intensity (583.2 KeV, 727.3 KeV, and 860.6 KeV), and high-intensity (1620.5 KeV and 2614.7 KeV). Although gamma-ray energy is much higher than that of low-energy X-rays, gamma-rays have greater penetrating power. The gamma photons released during the decay process are isotropic in three dimensions and cannot be focused. Furthermore, thorium oxide has a low decay activity. Therefore, the energy deposition of gamma rays in the fiber optic probe module is lower than that of low-energy X-rays. In this test, the fiber optic probe was placed on the side of the thorium oxide powder to detect gamma rays. The light-emitting diode emitted a faint red light, and the signal was extremely unstable. The test concluded that the detection device has the ability to detect low-energy X-rays, and the threshold value of the detection device for detecting low-energy X-ray energy can be adjusted by adjusting the resistance values of each resistor in the circuit. The detection device can detect low-energy gamma rays, but it has higher requirements on the performance of the fiber optic probe module and the circuit sensitivity.

[0082] The number of devices and processing scales described herein are intended to simplify the description of the present invention. Applications, modifications, and variations of the present invention will be readily apparent to those skilled in the art.

[0083] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A portable low-energy ray detection device, characterized in that: include: A fiber optic probe module comprising: Optical fiber core; A cylindrical aluminum foil mold having a hollow structure, wherein the optical fiber core is inserted into the cylindrical aluminum foil mold, and an annular cavity is formed between the optical fiber core and the cylindrical aluminum foil mold; Composite scintillator layer, Cs3Cu2I5:Mn 2+ A mixture of 15% scintillator material and UV glue is injected into the annular cavity and cured to form the composite scintillator layer, which is used to absorb low-energy X-rays or gamma rays and emit fluorescence outward. The cylindrical aluminum foil mold serves as a reflective layer to reflect the stimulated fluorescence. A 3D printed fiber cap, wherein the fiber probe module is fixedly disposed inside the 3D printed fiber cap to form a complete fiber probe; a photocell, whose photosensitive surface is coupled to the output end of the optical fiber probe and converts the fluorescence signal into an electrical signal; The alarm circuit control module includes a transistor control circuit and a light-emitting diode connected to the transistor control circuit. The photocell is connected to the transistor control circuit. When the transistor control circuit is in a saturated conduction state, the light-emitting diode emits light.

2. The portable low-energy ray detection device according to claim 1, characterized in that: The triode control circuit specifically includes: NPN transistor, whose emitter e2 is connected to the positive electrode of the light emitting diode, collector c2 is connected to the positive electrode of the power supply through the adjustable resistor R5, and the negative electrode of the light emitting diode is grounded; A PNP transistor, whose emitter e1 is connected to the positive electrode of the power supply through an adjustable resistor R2, and whose collector c1 is connected to both the base b2 of the NPN transistor and one end of the adjustable resistor R1, and the other end of the adjustable resistor R1 is grounded; Among them, the positive electrode of the photocell is connected to the base b1 of the PNP transistor, the negative electrode of the photocell is connected to one end of the adjustable resistor R3 used to protect the photocell, the other end of the adjustable resistor R3 is grounded, and the PNP transistor and the NPN transistor perform cascade amplification on the electrical signal output by the photocell; a control switch is also arranged between the positive electrode of the power supply and the adjustable resistor R2.

3. The portable low-energy ray detection device according to claim 2, characterized in that: The emitter e2 current of the NPN transistor is the current i of the light emitting diode e2 , the expression is: + , Among them, i e1 is the emitter e1 current of the PNP transistor, i b1 is the base b1 current of the PNP transistor, V c1 is the collector c1 voltage of the PNP transistor, V1 is the power supply voltage, and the photosensitivity of the transistor control circuit is adjusted by adjusting the resistance value of the adjustable resistor R1.

4. The portable low-energy ray detection device according to claim 2, characterized in that: It also includes a 3D printed coupling mold, which is a solid rectangular structure. A through cylindrical hole is set along the long axis of the rectangular structure, and the aperture of the cylindrical hole is adapted to the outer diameter of the 3D printed optical fiber cap; a groove is also set at one end of the rectangular structure, and the size of the groove is adapted to the size of the photocell. The groove is connected to the cylindrical hole, and the optical fiber probe is inserted into the cylindrical hole and fixed, and the output end of the optical fiber probe is facing the groove; the photocell is fixed in the groove, so that the photosensitive surface of the photocell is in contact with the output end of the optical fiber probe.

5. The portable low-energy ray detection device according to claim 1, characterized in that: The Cs3Cu2I5:Mn 2+ In the mixture of 15% scintillator material and UV glue, Cs3Cu2I5:Mn 2+ The mass ratio of 15% scintillator material and UV glue is 0.7~1.3:1; the Cs3Cu2I5:Mn 2+ The preparation method of the mixture of 15% scintillator material and UV glue comprises the following steps: a. weighing Cs3Cu2I5:Mn 2+ 15% scintillator material powder is poured into UV glue; b. Use glass rod to stir thoroughly to make Cs3Cu2I5:Mn 2+ 15% scintillator material powder is evenly dispersed in UV glue; c. Use a 1ml syringe with a 27G ultra-fine dispensing needle to dissolve Cs3Cu2I5:Mn 2+ 15% scintillator material and UV glue mixture is injected into the annular cavity; d. Injection and curing are carried out in 3-4 stages, and after each injection, 220-260 nm UV light is irradiated for 30 s to ensure that Cs3Cu2I5:Mn 2+ The mixture of 15% scintillator material and UV glue is completely cured.

6. The portable low-energy ray detection device according to claim 1, characterized in that: The 3D printed fiber optic cap has a wall thickness of 1 mm, an inner diameter of 3.5 mm, an outer diameter of 4.5 mm, and a length of 18 mm. The material used for the 3D printed fiber optic cap is nylon PA12. The cylindrical aluminum foil mold has a wall thickness of 50 μm-0.1 mm, a length of 17.5 mm, and an inner diameter of 3 mm. The minimum energy measurement threshold of low-energy X-rays or gamma rays is 20 KeV. The photocell is a 2DU3 silicon photocell.

7. The portable low-energy ray detection device according to claim 2, characterized in that: The Cs3Cu2I5:Mn 2+ The emission wavelength range of the 15% scintillator material is 400-650nm; the optical fiber core is a PMMA optical fiber core with a diameter of 1.985mm, and the applicable wavelength range of the optical fiber core is 400-700nm; the 3D printed optical fiber cap is hollow cylindrical, with one end being tapered and the other end being open.

8. The portable low-energy ray detection device according to claim 2, characterized in that: The resistance range of the adjustable resistor R1 is set to 300Ω to 20kΩ to detect low-energy X-rays or gamma rays of different intensities; the power source is a lithium battery.

9. The portable low-energy ray detection device according to claim 4, characterized in that: It also includes a packaging shell, in which the optical fiber probe, the photocell, the alarm circuit control module and the 3D printing coupling mold are all packaged. One end of the packaging shell is conical, and the light-emitting diode passes through the shell wall of the packaging shell and is fixedly set on the packaging shell; the control switch passes through the shell wall of the packaging shell and is fixedly set on the packaging shell.

10. The method for preparing the portable low-energy ray detection device according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Obtain Cs3Cu2I5:Mn 2+ 15% scintillator material, and Cs3Cu2I5:Mn 2+ 15% is mixed with UV glue as scintillator material to form Cs3Cu2I5:Mn 2+ 15% scintillator material and UV glue mixture; S2, insert the optical fiber core into the cylindrical aluminum foil mold, and Cs3Cu2I5:Mn 2+ A mixture of 15% scintillator material and UV glue is injected into the annular cavity between the optical fiber core and the cylindrical aluminum foil mold. The injection and curing are performed in stages to obtain an optical fiber probe module. During the glue injection process, the optical fiber core must be located at the center of the cylindrical aluminum foil mold. S3. Using a light-curing 3D printer to obtain a 3D-printed fiber cap, injecting UV glue into the inner side wall of the 3D-printed fiber cap, inserting the fiber probe module into the 3D-printed fiber cap, and encapsulating it with UV glue to obtain a fiber probe; S4. Use a photocell as a photoelectric conversion device to convert the optical signal into an electrical signal; use a 3D printer to obtain a 3D printed coupling mold, fix the photocell in a groove at one end of the 3D printed coupling mold using UV glue, insert the other end into the output end of the optical fiber probe, and make the photosensitive surface of the photocell fit the output end of the optical fiber probe; S5. Make a PCB circuit board of the alarm circuit control module; S6. Use a 3D printer to obtain a packaging shell, and package the optical fiber probe, the photocell, the 3D printed coupling mold, and the PCB circuit board in the packaging shell.

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