Detection device

Abstract

The invention relates to a detection device which comprises a shell and a cover body, the shell defines an inner cavity, one end of the shell is provided with an opening communicated with the inner cavity, and the cover body is connected with the shell and covers the opening; a first through hole is formed in one surface, far away from the cover body, of the shell, a main detector is arranged in the inner cavity, the main detector is fixed with the shell, a second through hole is formed in the main detector, the second through hole is aligned with the first through hole, and a light sensing surface of the main detector faces the cover body. The detection device provided by the invention can realize effective separation of the incident X-ray and the back scattering X-ray in a short distance, and can realize convenient optical path adjustment and accurate measurement of the back scattering X-ray.

Description

Technical Field

[0001] This invention relates to the field of optical equipment technology, and more specifically to a detection device. Background Technology

[0002] X-rays, as electromagnetic radiation with extremely short wavelengths, are widely used in materials science, physics, and industrial inspection because they can penetrate matter and interact with atoms. Among these applications, the interaction between X-rays and crystals is a crucial method for studying the microstructure of matter. Bragg diffraction is the core principle of this process—when X-rays irradiate a crystal, the regularly arranged atoms within the crystal scatter the X-rays. If the optical path difference of the scattered light satisfies a specific condition (i.e., the Bragg condition: 2dsinθ=nλ, where d is the interplanar spacing, θ is the incident angle, λ is the X-ray wavelength, and n is an integer), the scattered light will form reinforced interference, exhibiting a clear diffraction signal. In Bragg diffraction, when the incident angle θ is close to 90°, the angle between the incident X-ray and the crystal surface is extremely small. At this point, the propagation direction of the diffracted light is almost opposite to that of the incident light (similar to "returning along the same path"). This special diffraction phenomenon is called X-ray backscattering. Backscattering has irreplaceable value in some fields due to its combination of "wide angle acceptance" (i.e., allowing diffraction to still occur even with large angular deviations) and high energy resolution. For example, in scenarios such as free electron laser (XFEL) resonator design, high-resolution X-ray spectrometer development, and precision measurement, backscattering is a key technology for achieving high-precision wavelength selection and X-ray reflection.

[0003] Because the incident and diffracted light propagate in almost overlapping (collinear) directions, the detector has difficulty effectively separating them, making the measurement signal susceptible to interference from the incident light. Therefore, measuring the backscattered signal is a technical challenge. Figure 1 As shown, existing technologies typically introduce deflection crystals in the optical path to change the beam direction in order to separate the incident light and the diffracted light. The X-rays emitted by the light source 10 are first diffracted by the deflection crystal 20 and then irradiate the backscattering crystal 30. The reflected X-rays are then transmitted through the deflection crystal 20 and irradiate the detector 40.

[0004] However, existing technologies require repeated calibration of the diffraction angles of each crystal and have "detection blind spots" (when the angle deviation is too small, the diffracted light will be reflected by the deflecting crystal 20 again instead of being transmitted); in addition, the deflecting crystal 20 requires an extremely thin crystal (thick crystals will severely attenuate X-rays), and the backscattered diffraction intensity cannot be directly obtained, so the diffraction efficiency cannot be accurately measured.

[0005] The detection device of the present invention can effectively separate incident X-rays and backscattered X-rays within a short distance, and can also achieve convenient optical path adjustment and accurate measurement of backscattered X-rays. Summary of the Invention

[0006] The purpose of this invention is to provide a detection device that can effectively isolate the interference of incident light, achieve higher measurement accuracy, and facilitate convenient optical path adjustment.

[0007] To achieve the above objectives, the present invention provides a detection device, comprising a housing and a cover, wherein the housing defines an inner cavity, one end of the housing has an opening communicating with the inner cavity, and the cover is connected to the housing and covers the opening; a first through hole is provided on the side of the housing away from the cover, a main detector is provided in the inner cavity, the main detector is fixed to the housing, a second through hole is provided on the main detector, the second through hole is aligned with the first through hole, and the photosensitive surface of the main detector faces the cover.

[0008] Optionally, the second through-hole is located at the center of the main detector.

[0009] Optionally, the first through hole is frustum-shaped and its diameter gradually decreases as it approaches the cover.

[0010] Optionally, the second through hole is circular and its diameter is equal to the minimum diameter of the first through hole.

[0011] Optionally, it also includes a light-blocking paper, which is fixed to the cover and covers the opening, and the light-blocking paper is used to block visible light.

[0012] Optionally, the opening end of the housing is provided with a groove, and the cover is provided with a protrusion, the protrusion matching the groove to make the cover and the housing sealed together.

[0013] Optionally, the protrusion defines a mounting cavity, and the light-shielding paper is fixed inside the mounting cavity.

[0014] Optionally, it further includes a first auxiliary detector and a second auxiliary detector, both of which are located in the inner cavity and fixed to the housing. The first auxiliary detector is adjacent to the main detector in a first direction, and the second auxiliary detector is adjacent to the main detector in a second direction. The first direction and the second direction are perpendicular to each other, and the photosensitive surfaces of the first auxiliary detector and the second auxiliary detector both face the cover.

[0015] Optionally, the main detector, the first auxiliary detector, and the second auxiliary detector are the same detector.

[0016] Optionally, the photosensitive surfaces of the main detector, the first auxiliary detector, and the second auxiliary detector are coplanar. Attached Figure Description

[0017] Figure 1This is a schematic diagram of the structure of a prior art backscatter imaging device;

[0018] Figure 2 This is a schematic diagram of the housing of the detection device according to an embodiment of the present invention;

[0019] Figure 3 This is a schematic diagram of the structure of the cover of the detection device according to an embodiment of the present invention;

[0020] Figure 4 This is a front view of the housing of the detection device according to an embodiment of the present invention;

[0021] Figure 5 This is a rear view of the housing of the detection device according to an embodiment of the present invention;

[0022] Figure 6 This is a schematic diagram of the backscatter imaging device using the detection device of an embodiment of the present invention. Detailed Implementation

[0023] The preferred embodiments of the present invention are given below with reference to the accompanying drawings and described in detail.

[0024] like Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, this embodiment of the invention provides a detection device, which includes a housing 100 and a cover 200. The housing 100 defines an inner cavity 110. One end of the housing 100 has an opening that communicates with the inner cavity 110. The cover 200 is connected to the housing 100 and covers the opening. A first through hole 120 is provided on the side of the housing 100 away from the cover 200. A main detector 310 is provided in the inner cavity 110. The main detector 310 is fixed to the housing 100. A second through hole 311 is provided on the main detector 310 (the second through hole 311 may be located at the center of the main detector 310). The second through hole 311 is aligned with the first through hole 120. The photosensitive surface of the main detector 310 faces the cover 200. Figure 6 As shown, in use, the detection device is located between the light source 400 and the backscattering crystal 500. The side of the housing 100 of the detection device away from the cover 200 faces the light source 400, while the cover 200 faces the backscattering crystal. X-rays emitted from the light source 400 pass sequentially through the first through-hole 120 and the second through-hole 311, then through the cover 200, and then irradiate the backscattering crystal 500, forming backscattered X-rays (i.e., diffracted light). The backscattered X-rays pass through the cover 200 and enter the inner cavity 110 of the housing 100, irradiating the photosensitive surface of the main detector 310. Although the opening design on the main detector 310 will create a certain detection dead angle, combined with the characteristics of the wide backscattering wobble curve, this dead angle is usually smaller than the width of the wobble curve and will not significantly affect the backscattering measurement results.

[0025] Since both the housing 100 and the main detector 310 have through holes, the detection device can be located between the light source 400 and the backscattering crystal 500. Incident X-rays can pass through the second through hole 311 of the main detector 310 without being received by it, while backscattered X-rays can be received by the main detector 310. The incident and backscattered X-rays do not interfere with each other, effectively separating them and significantly improving signal contrast, thereby enhancing measurement accuracy. When the distance between the main detector 310 and the backscattering crystal 500 exceeds 30 cm, the detection dead angle does not exceed 0.1°.

[0026] In some embodiments, the first through-hole 110 can be a frustum-shaped hole with its diameter being largest further away from the cover 200 and smallest closer to the cover 200. That is, the closer to the cover 200, the larger the diameter of the first through-hole 110. This through-hole with a gradually changing diameter can effectively collimate the incident X-rays and reduce beam divergence. The second through-hole 311 is circular and its diameter is the same as the minimum diameter of the first through-hole 110. For example, the maximum diameter of the first through-hole 110 is 2.4 mm, the minimum diameter is 2 mm, and the diameter of the second through-hole 311 is 2 mm.

[0027] In some embodiments, the detection device further includes a light-shielding paper (e.g., black paper, aluminum foil, or a combination of both), which covers the opening of the housing 100 and is used to block visible light to prevent interference with the detection signal. After the light-shielding paper covers the opening, the cover 200 can be fixed to the housing 100, with the light-shielding paper sandwiched between the cover 200 and the housing 100, thereby achieving fixation.

[0028] The opening end of the housing 100 may be provided with a groove 130, and the cover 200 is provided with a protrusion 210. The protrusion 210 matches the groove 130. By inserting the protrusion 210 into the groove 130, a tight fit can be achieved between the cover 200 and the housing 100. Then, the cover 200 and the housing 100 are fastened with screws to achieve a sealed connection between the cover 200 and the housing 100, preventing visible light from entering the inner cavity 110. The protrusion 210 may define a mounting cavity 220, in which the light-shielding paper may be located.

[0029] To achieve precise adjustment of the optical path, two auxiliary detectors, namely a first auxiliary detector 320 and a second auxiliary detector 330, can be set next to the main detector 310. Both the first auxiliary detector 320 and the second auxiliary detector 330 are fixed to the housing 100. The photosensitive surfaces of the main detector 310, the first auxiliary detector 320, and the second auxiliary detector 330 are coplanar (i.e., on the same optical axis plane), and both photosensitive surfaces face the cover 200. The first auxiliary detector 320 and the main detector 310 are sequentially arranged along a first direction and in contact with each other, while the second auxiliary detector 330 and the main detector 310 are sequentially arranged along a second direction and in contact with each other. The first and second directions are perpendicular to each other and both perpendicular to a third direction, which is perpendicular to the photosensitive surface of the main detector 310. The first and second directions are two directions on the photosensitive surface. For example, the first direction is the X-axis, the second direction is the Y-axis, and the third direction is the Z-axis.

[0030] The main detector 310, the first auxiliary detector 320 and the second auxiliary detector 330 can use the same detector; for example, a PIN photodiode with the same specifications and a photosensitive surface area of ​​10mm×10mm.

[0031] The optical path adjustment method during use is as follows:

[0032] First, set the diffraction angle of the backscattering crystal 500 to θ (slightly less than 90 degrees). The value of θ can be calculated using the following formula:

[0033] ,

[0034] Where d is the distance from the center of the first auxiliary detector 320 to the center of the second through-hole 311, and L is the distance between the main detector 310 and the backscattering crystal 500. Then, the light source 400 emits X-rays with energy corresponding to the diffraction angle θ (the energy of the X-rays can be obtained using Bragg's formula). After diffraction by the backscattering crystal 500, the X-rays form backscattered X-rays, which can then irradiate the first auxiliary detector 320. The energy of the X-rays emitted by the light source 400 is then gradually increased while the backscattering crystal 500 is rotated to change the diffraction angle, causing the backscattered X-ray spot to move along the X-direction towards the main detector 310 until the main detector 310 receives the signal and the signal on the first auxiliary detector 320 disappears. Simultaneously, observe the second auxiliary detector 330. If it receives a signal, it indicates that the backscattering crystal 500 is tilted in the Y direction. The backscattering crystal 500 can then be rotated around the X-axis until the signal on the second auxiliary detector 330 disappears. At this point, the backscattering crystal 500 is nearly perpendicular to the incident X-ray in the Y-square, and the backscattered X-ray can accurately illuminate the main detector 310, thus completing the fine adjustment of the optical path. By using the first auxiliary detector 320 and the second auxiliary detector 330, the problem of optical path alignment caused by the invisibility of X-rays is solved, thereby enabling convenient and fine adjustment of the optical path.

[0035] The detection device of this invention can effectively separate incident X-rays and backscattered X-rays within a short distance, and can also achieve convenient optical path adjustment and accurate measurement of backscattered X-rays.

[0036] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the invention. Various variations can be made to the above embodiments of the present invention. That is, all simple and equivalent changes and modifications made based on the claims and description of this invention fall within the protection scope of the claims of this patent. All aspects not described in detail in this invention are conventional technical content.

Claims

1. A detection device, characterized in that, The application relates to a camera, which comprises a shell and a cover, the shell defines an inner cavity, one end of the shell is provided with an opening communicating with the inner cavity, the cover is connected with the shell and covers the opening; a first through hole is arranged on a side of the shell far from the cover, a main detector is arranged in the inner cavity, the main detector is fixed with the shell, a second through hole is arranged on the main detector, the second through hole is aligned with the first through hole, and a photosensitive surface of the main detector faces the cover.

2. The probe device of claim 1, wherein, The second through hole is located at the center of the main detector.

3. The probe device of claim 1, wherein, The first through hole is a circular truncated cone, and the diameter gradually decreases as it approaches the cover.

4. The probe device of claim 3, wherein, The second through hole is circular, and the diameter is equal to the minimum diameter of the first through hole.

5. The probe device of claim 1, wherein, The camera further comprises a light-shielding paper, which is fixed on the cover and covers the opening, and is used for shielding visible light.

6. The probe device of claim 5, wherein, The opening end of the shell is provided with a groove, the cover is provided with a protrusion, the protrusion and the groove are matched with each other, so that the cover and the shell are sealingly connected.

7. The probe device of claim 6, wherein, The protrusion defines a mounting cavity, and the light-shielding paper is fixed in the mounting cavity.

8. The probe device of claim 1, wherein, The camera further comprises a first auxiliary detector and a second auxiliary detector, the first auxiliary detector and the second auxiliary detector are located in the inner cavity and fixed with the shell, the first auxiliary detector is adjacent to the main detector in a first direction, the second auxiliary detector is adjacent to the main detector in a second direction, the first direction and the second direction are perpendicular to each other, and the photosensitive surfaces of the first auxiliary detector and the second auxiliary detector both face the cover.

9. The probe device of claim 8, wherein, The main detector, the first auxiliary detector and the second auxiliary detector are the same detector.

10. The probe device of claim 8, wherein, The photosensitive surfaces of the main detector, the first auxiliary detector and the second auxiliary detector are coplanar.

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