X-ray image intensifier and X-ray camera

Abstract

The utility model discloses an X-ray image intensifier, which belongs to the technical field of X-ray imaging and is sequentially provided with an incidence window, a scintillator, a photoelectric cathode, an anti-ion feedback film, a micro-channel plate and a fluorescent screen along the incidence direction of X-rays. The incident window, the scintillator and the photoelectric cathode are tightly attached; the photoelectric cathode, the anti-ion feedback film, the micro-channel plate and the fluorescent screen are arranged at intervals; a plurality of one-way channels which form included angles with the horizontal plane in the axial direction are distributed on the micro-channel plate dot matrix; the photoelectric cathode, the anti-ion feedback film, the micro-channel plate and the fluorescent screen are arranged at intervals, so that the influence of ion feedback on the photoelectric cathode and the micro-channel plate can be effectively reduced, and the effects of reducing noise and improving the sensitivity and signal quality of the detector are achieved; meanwhile, the one-way channels in the micro-channel plate are obliquely arranged, so that the collision probability of electrons can be increased to strengthen the electron multiplication effect, ion feedback can be further reduced, the multiplication stability is improved, and noise and background current are reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of X-ray imaging, and in particular relates to an X-ray image intensifier and an X-ray camera. Background Art

[0002] X-ray cameras are imaging devices that can detect X-rays. Currently, X-ray cameras are widely used in medical diagnosis, industrial non-destructive testing, safety monitoring, and scientific research. However, current X-ray cameras generally suffer from poor sensitivity, high noise, low detection efficiency, and susceptibility to external environmental influences, resulting in poor device stability. Utility Model Content

[0003] The technical problem to be solved by the present invention is: how to provide an X-ray image intensifier and an X-ray camera that can solve the above problems.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] An X-ray image intensifier is provided with an incident window, a scintillator, a photocathode, an anti-ion feedback membrane, a microchannel plate and a fluorescent screen in sequence along the incident direction of the X-ray;

[0006] The incident window, scintillator and photocathode are tightly fitted;

[0007] The photocathode, anti-ion feedback membrane, microchannel plate and fluorescent screen are arranged at intervals;

[0008] The microchannel plate is distributed with a plurality of unidirectional channels whose axes form an angle with the horizontal plane.

[0009] Furthermore, the pore size of the one-way channel is 2 μm to 12 μm.

[0010] Furthermore, along the incident direction of the X-ray, the distance between the one-way channel and the horizontal plane gradually decreases.

[0011] Furthermore, one end of the one-way channel close to the incident end of the microchannel plate is funnel-shaped.

[0012] Furthermore, the thickness of the microchannel plate is 0.5 mm to 1 mm.

[0013] Furthermore, the aspect ratio of the one-way channel is 40:1 to 60:1.

[0014] Furthermore, the angle between the one-way channel and the horizontal plane is 5° to 15°.

[0015] Furthermore, electrodes are provided at both the incident end and the exit end of the microchannel plate.

[0016] Furthermore, the electrode provided at the incident end of the microchannel plate and the electrode provided at the exit end of the microchannel plate respectively extend toward the interior of the one-way channel;

[0017] The length of the electrode extending into the one-way channel is 2 to 3 times the aperture of the one-way channel.

[0018] The utility model also provides an X-ray camera, comprising a housing, an optical fiber light cone, a scientific camera and the above-mentioned X-ray image intensifier;

[0019] The shell is a cylindrical structure with openings at both ends;

[0020] One end of the shell is connected to the incident end of the scientific camera;

[0021] The optical fiber light cone and the X-ray image intensifier are both arranged in the housing;

[0022] The input window is connected to the other end of the housing, and the input window, the housing and the scientific camera form a sealed space;

[0023] The fluorescent screen and the incident end of the scientific camera are connected through an optical fiber light cone.

[0024] The beneficial effects of the present invention are as follows: the X-ray image intensifier provided by the present invention can effectively reduce the influence of ion feedback on the photocathode and the microchannel plate by arranging the photocathode, the anti-ion feedback membrane, the microchannel plate and the fluorescent screen at intervals, thereby reducing noise and improving the sensitivity and signal quality of the detector; at the same time, the unidirectional channel in the microchannel plate is arranged at an angle, which can not only increase the collision probability of electrons to enhance the electron multiplication effect, but also further reduce ion feedback, improve the multiplication stability, and reduce noise and background current. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the working principle of an X-ray camera according to a specific embodiment of the present invention;

[0026] Figure 2 This is a schematic structural diagram of a microchannel plate according to a specific embodiment of the present invention;

[0027] Figure 3 A schematic diagram of the structure of a one-way channel according to a specific embodiment of the present invention and a diagram showing its working principle;

[0028] Figure 4 This is a schematic structural diagram of an X-ray camera according to a specific embodiment of the present invention;

[0029] Description of labels:

[0030] 1. Entrance window;

[0031] 2. Scintillator;

[0032] 3. Photocathode;

[0033] 4. Anti-ion feedback membrane;

[0034] 5. Microchannel plate; 51. One-way channel;

[0035] 6. Fluorescent screen;

[0036] 7. Shell;

[0037] 8. Fiber optic light cone;

[0038] 9. Scientific camera;

[0039] 10. X-ray;

[0040] 11. Ultraviolet light;

[0041] 12. Optoelectronics;

[0042] 13. Visible light. DETAILED DESCRIPTION

[0043] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following description is given in conjunction with the embodiments and the accompanying drawings.

[0044] The key concept of the present invention is that the photocathode, anti-ion feedback membrane, microchannel plate and fluorescent screen are spaced apart to effectively reduce the impact of ion feedback on the photocathode and microchannel plate, thereby reducing noise and improving the sensitivity and signal quality of the detector; and the unidirectional channel in the microchannel plate is tilted to increase the collision probability of electrons to enhance the electron multiplication effect, further reduce ion feedback, improve multiplication stability, and reduce noise and background current.

[0045] Please refer to Figures 1 to 4 The X-ray image intensifier provided by the present invention is provided with an incident window 1, a scintillator 2, a photocathode 3, an anti-ion feedback membrane 4, a microchannel plate 5 and a fluorescent screen 6 in sequence along the incident direction of the X-ray;

[0046] The incident window 1, the scintillator 2 and the photocathode 3 are tightly fitted;

[0047] The photocathode 3, the anti-ion feedback membrane 4, the microchannel plate 5 and the fluorescent screen 6 are arranged at intervals;

[0048] The microchannel plate 5 has a plurality of one-way channels 51 distributed in a dot matrix, the axes of which form an angle with the horizontal plane.

[0049] Specifically, the distance between the anti-ion feedback membrane 4 and the photocathode 3 is 1 mm to 5 mm, preferably 3 mm; the distance between the anti-ion feedback membrane 4 and the microchannel plate 5 is 5 mm to 10 mm, preferably 7 mm; the fluorescent screen 6 includes a conversion layer and a reflective substrate; the conversion layer is spin-coated on the incident end of the reflective substrate; the conversion layer is made of any commercially available material that can convert the multiplied photoelectrons into visible photons, such as CsPbBr3NCs; the reflective substrate is made of aluminum; the material of the photocathode 3 can be any commercially available material with high luminous efficiency and The perovskite material CsPbX3 (X = Cl, Br, I) has the characteristics of fast decay time, tunable emission wavelength, high sensitivity and strong X-ray attenuation; the scintillator 2 is made of any commercially available material that can convert X-rays into ultraviolet light, such as YAlO3:Ce (YAP:Ce); the optimal emission spectrum of the scintillator 2 is between 200nm and 400nm; the thickness of the scintillator 2 is 30nm to 400nm, preferably 150nm; the incident surface and side surface of the scintillator 2 are coated with a layer of evaporated reflective film, which is any commercially available material that can convert X-rays into ultraviolet light. The reflective film is made of a commercially available metal aluminum film, silver film, or gold film with high reflectivity, and the thickness of the reflective film is 50 nm to 250 nm, preferably 150 nm; the microchannel plate 5 is a single-layer, double-layer, or multi-layer structure of a focused output type; the material of the microchannel plate 5 can be lead silicate glass, a semiconductor microchannel plate 5, a silicon microchannel plate 5, or an anodized aluminum microchannel plate 5; both ends of the microchannel plate 5 are plated with nickel-chromium metal electrodes, and the outer ring is a circle of a solid edge plated with nickel-chromium metal film but without a channel; the anti-ion feedback membrane 4 is any commercially available material that can reduce the optical halo phenomenon The optical fiber is made of a material such as Al2O3; the thickness of the fluorescent screen 6 is 20nm~500nm, preferably 400nm; the distance between the photocathode 3 and the microchannel plate 5 is 100μm~500μm, preferably 300μm; the distance between the microchannel plate 5 and the fluorescent screen 6 is 100μm~500μm, preferably 300μm; the material of the input window can be aluminum or beryllium, and the thickness of the input window is 0.2mm~0.6mm. Preferably, the thickness of the input window is 0.3mm, so that the input window can block stray light.

[0050] As can be seen from the above description, the beneficial effects of the present invention are: providing an X-ray image intensifier, compared with the existing X-ray image intensifier, the photocathode 3, the anti-ion feedback membrane 4, the microchannel plate 5 and the fluorescent screen 6 are arranged at intervals, which can ensure that the ions generated by the secondary collision of electrons can effectively diffuse to avoid excessive interference with the photoelectric signal; at the same time, it can effectively reduce the influence of ion feedback, and ensure that the device has good signal transmission efficiency; and the inclined one-way channel 51 can not only increase the path length and difficulty of ion backflow, so that most of the ions can be absorbed or diffused before reaching the photocathode 3, thereby reducing damage to the photocathode 3; it can also make the process of each electron collision and secondary electron emission more uniform and controllable, ensure the consistency of the output electron number and the stability of the amplified signal, and help to improve the sensitivity and signal gain of the device; and further avoid the problem of background current or noise caused by external noise electrons or irrelevant electrons passing through the microchannel plate 5.

[0051] Furthermore, the pore size of the one-way channel 51 is 2 μm to 12 μm.

[0052] Furthermore, along the incident direction of the X-ray, the distance between the one-way channel 51 and the horizontal plane gradually decreases.

[0053] Furthermore, one end of the one-way channel 51 close to the incident end of the microchannel plate 5 is funnel-shaped.

[0054] Furthermore, the thickness of the microchannel plate 5 is 0.5 mm to 1 mm.

[0055] Furthermore, the aspect ratio of the one-way channel 51 is 40:1 to 60:1.

[0056] Furthermore, the angle between the one-way channel 51 and the horizontal plane is 5° to 15°.

[0057] Specifically, the pore size of the one-way channel 51 of the present invention is 4μm to 10μm, preferably 6μm; the thickness of the microchannel plate 5 is 0.6mm to 0.9mm, preferably 0.7mm; the aspect ratio of the one-way channel 51 is 45:1 to 55:1, preferably 50:1; the angle between the one-way channel 51 and the horizontal plane is 8° to 12°, preferably 10°; the opening rate of the funnel-shaped end of the one-way channel 51 is 90%;.

[0058] As can be seen from the above description, the design has made specific modifications to the structural parameter settings of the microchannel plate 5 and the layout of the one-way channel 51. By tilting the one-way channel 51 and setting its incident end to be funnel-shaped, it can not only increase the amount of electrons accepted and the collision probability, thereby ensuring the electron multiplication effect; but also reduce the situation of ion feedback, that is, when electrons collide with the one-way channel 51 and are secondary-emitted, corresponding ions will be generated. These ions will be reversely accelerated back to the surface of the photocathode 3 under the action of the electric field, causing the photocathode 3 to age or increase signal noise. The tilted one-way channel 51 can increase the path length and difficulty of ion reflux, so that most of the ions are absorbed or diffused before reaching the photocathode 3, thereby reducing damage to the photocathode 3. The tilted one-way channel 51 can also help electrons move along a certain path, avoid excessive randomness, and make each electron collision and secondary electron emission process more uniform and controllable, thereby ensuring the consistency of the output electron number and the stability of the amplified signal, which helps to improve the sensitivity and signal gain of the device.

[0059] Furthermore, electrodes are provided at both the incident end and the exit end of the microchannel plate 5 .

[0060] Furthermore, the electrode provided at the incident end of the microchannel plate 5 and the electrode provided at the exit end of the microchannel plate 5 extend toward the interior of the one-way channel 51 respectively;

[0061] The length of the electrode extending into the one-way channel 51 is 2 to 3 times the aperture of the one-way channel 51 .

[0062] Specifically, the cathode voltage Vc between the photocathode 3 and the input end of the microchannel plate 5, the voltage Vm between the input end and the output end of the microchannel plate 5, and the anode voltage Va between the output end of the microchannel plate 5 and the fluorescent screen 6 in the X-ray image intensifier are: 150-250V, 800-1200V, and 5000-6000V, respectively. The preferred values ​​of voltage Vc, voltage Vm, and voltage Va are 200V, 1000V, and 5500V, respectively.

[0063] As can be seen from the above description, the electrodes arranged at both ends of the microchannel plate 5 can form an electric field after being energized, thereby providing structural support for driving electrons to accelerate and multiply in the unidirectional channel 51; and further determining the depth of the electrode can not only determine the initial acceleration process of the electrons in the channel, but also avoid the situation where the electron acceleration is insufficient due to the electrode depth being too shallow, resulting in reduced multiplication efficiency; or the electron multiplication process is affected due to the electrode depth being too deep, thereby increasing noise and signal interference; at the same time, controlling the depth of the electrode to 2 to 3 times the channel aperture also helps to form a uniform and stable electric field, so that the electrons can be quickly accelerated and effectively emit secondary electrons when entering the channel, thereby optimizing the electron multiplication effect and improving the output quality of the signal.

[0064] The utility model also provides an X-ray camera, comprising a housing 7, an optical fiber light cone 8, a scientific camera 9 and the above-mentioned X-ray image intensifier;

[0065] The housing 7 is a cylindrical structure with openings at both ends;

[0066] One end of the housing 7 is connected to the incident end of the scientific camera 9;

[0067] The optical fiber light cone 8 and the X-ray image intensifier are both arranged in the housing 7;

[0068] The input window 1 is connected to the other end of the housing 7, and the input window, the housing 7 and the scientific camera 9 form a sealed space;

[0069] The incident end of the fluorescent screen 6 and the scientific camera 9 are connected via an optical fiber light cone 8 .

[0070] Furthermore, the fluorescent screen 6 is tightly fitted to the large end of the optical fiber cone 8;

[0071] The small end of the optical fiber light cone 8 is coupled to the incident end of the scientific camera 9 through a coupling adhesive.

[0072] Specifically, the housing 7 is welded in a high vacuum seal using indium sealing technology; an electrically insulating coating is applied to the outer surface of the housing 7, and the insulating material may be glass, plastic, or ceramic, and electrodes are sprayed on the outer surface of the housing 7. The photocathode 3, the microchannel plate 5, and the output phosphor screen 6 are all provided with electrical connection terminals, and the other end of the electrical connection terminal passes through the housing for connection to an external power supply; the scientific camera 9 is a scientific-grade CMOS (sCMOS) camera, which is used to convert the obtained visible light into a digital information image, and its optimal quantum efficiency is comparable to that of CsPbBr3 The optical fiber light cone 8 is matched with the optimal emission wavelength of NCs; a plurality of single filaments are arranged in the optical fiber light cone 8; the large end and the small end of the optical fiber light cone 8 are both circular; the size of the large end of the optical fiber light cone 8 matches the size of the output fluorescent screen 6; the height of the optical fiber light cone 8 is equal to the diameter of its large end, and the diameter of the single filament at the large end is 3μm to 12μm, preferably 8μm; the small end of the optical fiber light cone 8 and the incident end of the scientific camera 9 are coupled by a rapid curing method, and the optical curing glue used during coupling is UV photosensitive glue, which can be rapidly cured under the irradiation of ultraviolet light (300nm to 380nm), and the refractive index of the optical curing glue is 1.4 to 1.6, preferably 1.56; the thickness of the coupling layer formed after the adhesive is cured is less than 5μm, preferably 2μm.

[0073] As can be seen from the above description, the design has made specific modifications to the component structure of the X-ray camera of the utility model. Through the high-light flux fiber optic light cone 8, the high-sensitivity scientific camera 9 is combined with the improved high-gain X-ray image intensifier, which can provide structural support for achieving ultra-high-sensitivity X-ray imaging detection.

[0074] The X-ray image intensifier of the utility model can assist X-ray imaging detection work.

[0075] Please refer to Figures 1 to 4 , the first embodiment of the present utility model is:

[0076] An X-ray image intensifier is provided with an incident window 1, a scintillator 2, a photocathode 3, an anti-ion feedback membrane 4, a microchannel plate 5 and a fluorescent screen 6 in sequence along the incident direction of the X-rays; the incident window 1, the scintillator 2 and the photocathode 3 are tightly fitted; the photocathode 3, the anti-ion feedback membrane 4, the microchannel plate 5 and the fluorescent screen 6 are arranged at intervals; the microchannel plate 5 is dot-arrayed with a plurality of unidirectional channels 51 whose axes form an angle with the horizontal plane.

[0077] The pore size of the one-way channel 51 is 2 μm to 12 μm.

[0078] Along the incident direction of the X-ray, the distance between the one-way channel 51 and the horizontal plane gradually decreases.

[0079] One end of the one-way channel 51 close to the incident end of the microchannel plate 5 is funnel-shaped.

[0080] The thickness of the microchannel plate 5 is 0.5 mm to 1 mm.

[0081] The aspect ratio of the one-way channel 51 is 40:1 to 60:1.

[0082] The angle between the one-way channel 51 and the horizontal plane is 5° to 15°.

[0083] Electrodes are provided at both the incident end and the exit end of the microchannel plate 5 .

[0084] The electrode arranged at the incident end of the microchannel plate 5 and the electrode arranged at the exit end of the microchannel plate 5 extend into the inside of the one-way channel 51 respectively; the length of the electrode extending into the one-way channel 51 is 2 to 3 times the aperture of the one-way channel 51.

[0085] The second embodiment of the present invention is:

[0086] The present invention also provides an X-ray camera, comprising a housing 7, an optical fiber light cone 8, a scientific camera 9, and the X-ray image intensifier of the first embodiment; the housing 7 is a cylindrical structure with openings at both ends; one end of the housing 7 is connected to the incident end of the scientific camera 9; the optical fiber light cone 8 and the X-ray image intensifier are both arranged in the housing 7; the incident window 1 is connected to the other end of the housing 7, and the input window, the housing 7, and the scientific camera 9 form a sealed space; the fluorescent screen 6 and the incident end of the scientific camera 9 are connected via the optical fiber light cone 8.

[0087] The fluorescent screen 6 is tightly fitted to the large end of the optical fiber light cone 8 ; the small end of the optical fiber light cone 8 is coupled to the incident end of the scientific camera 9 via a coupling adhesive.

[0088] The working principle of the present invention is as follows: first, X-rays are emitted by the corresponding X-ray source and transmitted through the imaging object to form an X-ray beam with structural information of the imaging object. The X-ray beam passes through the input window and excites the scintillator 2 to emit an ultraviolet light signal with structural information; then, the ultraviolet light signal is converted into a photoelectron image through the photocathode 3, and the photoelectron image is emitted into the microchannel plate 5 through the anti-ion feedback membrane 4, and is enhanced by the microchannel plate 5 to form an electron multiplication image; then, the enhanced electronic image signal is converted into a visible light image through the fluorescent screen 6; then, the obtained visible light image is transmitted to the incident end of the scientific camera 9 through the optical fiber light cone 8 for photoelectric conversion processing to obtain a digital image of the imaging object; finally, it is transmitted to a related digital computer for display.

[0089] In summary, the X-ray image intensifier provided by the present invention arranges the photocathode, the anti-ion feedback membrane, the microchannel plate and the fluorescent screen at intervals, which can effectively reduce the influence of ion feedback on the photocathode and the microchannel plate, so as to reduce noise and improve the sensitivity and signal quality of the detector; and further makes specific modifications to the structural parameter setting of the microchannel plate and the layout of the one-way channel. By setting the one-way channel at an angle and setting its incident end to a funnel shape, it can not only increase the amount of electrons received and the probability of collision, thereby ensuring the electron multiplication effect; but also reduce the situation of ion feedback, that is, the electrons will produce secondary emission during the process of colliding with the one-way channel. Corresponding ions are generated, and these ions will be accelerated back to the surface of the photocathode under the action of the electric field, causing aging of the photocathode or increasing signal noise. The inclined unidirectional channel can increase the path length and difficulty of ion return, so that most ions are absorbed or diffused before reaching the photocathode, thereby reducing damage to the photocathode; and the inclined unidirectional channel can also help electrons move along a certain path, avoiding excessive randomness, making each electron collision and secondary electron emission process more uniform and controllable, thereby ensuring the consistency of the output electron number and the stability of the amplified signal, which helps to improve the sensitivity and signal gain of the device.

[0090] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent transformations made using the contents of the description and drawings of the present invention, or directly or indirectly applied in the relevant technical field, are also included in the patent protection scope of the present invention.

Claims

1. An X-ray image intensifier, comprising an incident window, a scintillator, a photocathode, an anti-ion feedback membrane, a microchannel plate, and a fluorescent screen, in sequence along the incident direction of the X-ray, characterized in that: The incident window, scintillator and photocathode are tightly fitted; The photocathode, anti-ion feedback membrane, microchannel plate and fluorescent screen are arranged at intervals; The microchannel plate is distributed with a plurality of unidirectional channels whose axes form an angle with the horizontal plane.

2. The X-ray image intensifier according to claim 1, characterized in that The pore size of the one-way channel is 2 μm to 12 μm.

3. The X-ray image intensifier according to claim 1, characterized in that Along the incident direction of the X-ray, the distance between the one-way channel and the horizontal plane gradually decreases.

4. The X-ray image intensifier according to claim 3, characterized in that One end of the one-way channel close to the incident end of the microchannel plate is funnel-shaped.

5. The X-ray image intensifier according to claim 1, characterized in that The thickness of the microchannel plate is 0.5 mm to 1 mm.

6. The X-ray image intensifier according to claim 1, characterized in that The aspect ratio of the one-way channel is 40:1 to 60:

1.

7. The X-ray image intensifier according to claim 2, characterized in that: The angle between the one-way channel and the horizontal plane is 5° to 15°.

8. The X-ray image intensifier according to claim 1, characterized in that Electrodes are provided at both the incident end and the exit end of the microchannel plate.

9. The X-ray image intensifier according to claim 8, characterized in that: The electrode disposed at the incident end of the microchannel plate and the electrode disposed at the exit end of the microchannel plate extend toward the interior of the one-way channel respectively; The length of the electrode extending into the one-way channel is 2 to 3 times the aperture of the one-way channel.

10. An X-ray camera, characterized in that: It comprises a housing, an optical fiber light cone, a scientific camera and the X-ray image intensifier according to any one of claims 1 to 9; The shell is a cylindrical structure with openings at both ends; One end of the shell is connected to the incident end of the scientific camera; The optical fiber light cone and the X-ray image intensifier are both arranged in the housing; The input window is connected to the other end of the housing, and the input window, the housing and the scientific camera form a sealed space; The fluorescent screen and the incident end of the scientific camera are connected through an optical fiber light cone.

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