Scintillator array and scintillation detector

Abstract

The embodiment of the present invention provides a scintillator array and a scintillation detector, the scintillator array comprising: a plurality of scintillators, the scintillators comprising scintillator crystals for absorbing high-energy rays and exciting scintillation light and a reflective layer for reflecting scintillation light, a portion of the outer surface of the scintillator crystals being covered by the reflective layer, at least a portion of the area of ​​the outer surface of the scintillator crystals not covered by the reflective layer forming a light-emitting surface; a plurality of scintillators are linearly arranged to form a scintillator array, and the light-emitting surfaces of two adjacent scintillators are located on opposite sides of the scintillator array. The scintillator array of the embodiment of the present invention reduces the possibility that the photoelectric detector receives light emitted from a light-emitting surface that is not configured corresponding to it, and reduces optical crosstalk; by increasing the distance between the photoelectric detectors, the possibility of interference between the electrical signals generated by the photoelectric detectors is reduced, thereby reducing the noise signal of the photoelectric sensor and improving the detection accuracy.

Description

Technical Field

[0001] The present invention relates to the field of radiation detection technology, and in particular to a scintillator array and a scintillation detector. Background Art

[0002] Scintillation detectors are one of the commonly used detectors for high-energy ray detection. Scintillation detectors usually use scintillators that can effectively block and absorb electromagnetic radiation and produce luminescence with electromagnetic radiation as detection materials.

[0003] When high-energy rays such as X-rays are incident on the scintillator, the photoelectric effect, Compton scattering effect and electron pair effect occur with the scintillator according to the energy of the rays, the effective atomic coefficient of the crystal and the density, and the energy is deposited in the scintillator and the excited scintillator produces scintillation light. The scintillation light in the visible light region or ultraviolet light region is converted and multiplied by a photoelectric detector such as a PMT (Photomultiplier Tube) connected to the scintillator to form a pulse electrical signal. After being collected, amplified and digitally processed by the circuit, it can be converted into radiation image data for reading and display processing by the imaging system.

[0004] Scintillation detectors have the characteristics of high detection efficiency and short resolution time, and are widely used in the research of nuclear medicine, safety inspection, high energy physics and cosmic ray detection. Summary of the invention

[0005] In view of this, embodiments of the present application are intended to provide a scintillator array and a scintillation detector capable of reducing interference to a photodetector.

[0006] To achieve the above purpose, the technical solution of the embodiment of the present application is implemented as follows:

[0007] An embodiment of the present invention provides a scintillator array, the scintillator array comprising:

[0008] A plurality of scintillators, each of which comprises a scintillator crystal for absorbing high-energy rays and exciting scintillation light and a reflective layer for reflecting the scintillation light, a portion of the outer surface of the scintillator crystal is covered by the reflective layer, and at least a portion of the outer surface of the scintillator crystal not covered by the reflective layer forms a light emitting surface;

[0009] A plurality of the scintillators are linearly arranged to form the scintillator array, and the light emitting surfaces of two adjacent scintillators are located at different sides of the scintillator array.

[0010] In some embodiments, the reflective layer is capable of transmitting high-energy rays, so that a partial area of ​​the reflective layer serves as a light incident surface of the scintillator.

[0011] In some embodiments, the flashing light is emitted only from the light emitting surface under the effect of the light reflecting layer.

[0012] In some embodiments, a portion of the outer surface of the scintillator is incident on the light incident surface of the scintillator as high-energy rays, and in a plane projection perpendicular to the incident direction of the high-energy rays, the projection of the light exit surface is outside the projection of the light incident surface.

[0013] In some embodiments, the light emitting surfaces of two scintillators separated by one scintillator are located on the same side of the scintillator array.

[0014] In some embodiments, a plurality of the scintillators are sequentially adhered along a first direction to form the scintillator array, the high-energy rays are incident on the scintillators along a second direction, and each of the light-emitting surfaces is located on opposite sides of the scintillator array along a third direction, wherein the first direction, the second direction and the third direction are orthogonal to each other.

[0015] In some embodiments, the scintillator is a rectangular parallelepiped, the first surface of the scintillator serves as the light incident surface for high-energy rays to enter the scintillator, the second surface adjacent to the first surface is the light emitting surface, the first surface and the second surface both intersect with the third surface, and the reflective layer covering the third surface is in contact with the adjacent scintillator.

[0016] An embodiment of the present invention provides a scintillation detector, comprising a photodetector, a light-transmitting layer capable of transmitting the scintillation light, and the scintillator array described in any of the above embodiments, wherein the light-transmitting layer is coupled between the photodetector and the light-emitting surface.

[0017] In some embodiments, the photodetector is structured such that the light emitting surface is located within the range of a light sensing surface of the photodetector for receiving the scintillation light.

[0018] In some embodiments, the photodetector is structured such that a photosensitive surface of the photodetector for receiving the scintillation light is located outside the irradiation range of high-energy rays.

[0019] The scintillators in the scintillator array of the embodiment of the present invention reflect the scintillation light through the reflective layer, and reflect the light to the light-emitting surface, so that the photodetector can better receive the light emitted from the light-emitting surface; the adjacent scintillators are arranged in a close proximity, so that the scintillator array structure is compact; the light-emitting surfaces of two adjacent scintillators are arranged on opposite sides of the scintillator array, which reduces the possibility that the photodetector receives light emitted from a light-emitting surface that is not configured corresponding to it, thereby reducing optical crosstalk; by increasing the distance between the photodetectors, the possibility that the electrical signals generated by the photodetectors interfere with each other is reduced, thereby reducing the noise signal of the photoelectric sensor and improving the detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic diagram of a scintillator in one embodiment of the present invention;

[0021] Figure 2 is a schematic diagram of a scintillator array in one embodiment of the present invention, wherein the dashed arrows indicate high-energy rays;

[0022] Figure 3 is a schematic diagram of a scintillator detector according to an embodiment of the present invention, wherein the dashed arrows indicate high-energy rays;

[0023] Figure 4 for Figure 3 Another perspective diagram of the scintillator detector in the middle, where the dashed arrows have the same meaning as Figure 3 ;

[0024] Figure 5 for Figure 4 Schematic diagram of the cross-section at position A in the middle.

[0025] Description of Reference Numerals

[0026] Scintillator array 10; scintillator 11; first surface 11a; second surface 11b; third surface 11c; scintillator crystal 111; light emitting surface 111a; light reflecting layer 112; light incident surface 112a; photodetector 20; light transmitting layer 30; photosensitive surface 20a DETAILED DESCRIPTION

[0027] It should be noted that, in the absence of conflict, the embodiments and technical features in the embodiments of the present application can be combined with each other, and the detailed description in the specific implementation method should be understood as an explanation of the purpose of the present application and should not be regarded as an improper limitation on the present application.

[0028] In the description of this application, the directions or positional relationships of “first direction”, “second direction”, “third direction”, “front”, “back”, “left”, “right”, “top” and “bottom” are based on the attached Figure 2 Regarding the orientation or positional relationship shown, it should be understood that these orientation terms are only for the convenience of describing the present application and simplifying the description, and 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 should not be understood as a limitation on the present application.

[0029] In the related art, the light-emitting surfaces of each scintillator in the scintillator array are located on the same side, and the spacing between the photodetectors arranged on the adjacent light-emitting surfaces is small. Due to the divergence of light, the light can escape and scatter from the area between the scintillator and the correspondingly configured photodetector. Therefore, the scintillation light emitted by the scintillator is easily received by the photodetector corresponding to the adjacent scintillator, thereby forming optical crosstalk between the photodetectors. In addition, the charge generated by the photodetector after collecting the scintillation light is easily collected by the adjacent photodetector, thereby forming electrical crosstalk between the photodetectors.

[0030] Therefore, in the related art, an isolation groove or a guard ring is set between adjacent scintillators to reduce the aforementioned optical crosstalk and electrical crosstalk. However, since the spacing between two adjacent photodetectors is very small, the process of making an isolation groove with an effective depth is complicated, and it is easy to affect the performance of the photodetector or even damage the photodetector. Setting a guard ring requires an ion implantation process, but due to the energy of the ion implantation equipment, the insufficient ion implantation depth leads to poor suppression of electrical crosstalk.

[0031] The embodiment of the present invention provides a scintillator array 10, referring to Figure 1 and Figure 2 , the scintillator array 10 comprises:

[0032] A plurality of scintillators 11, the scintillators 11 include scintillator crystals 111 for absorbing high-energy rays and exciting scintillation light and a reflective layer 112 for reflecting the scintillation light, a portion of the outer surface of the scintillator crystals 111 is covered by the reflective layer 112, and at least a portion of the outer surface of the scintillator crystals 111 not covered by the reflective layer 112 forms a light emitting surface 111a.

[0033] A portion of the scintillation light emitted by the scintillation crystal 111 when stimulated by high-energy rays can be emitted directly through the light-emitting surface 111a, and another portion is reflected once or multiple times by the reflective layer coated on the outer surface of the scintillation crystal 111 and then emitted from the light-emitting surface 111a. The photodetector 20 can receive the light emitted from the light-emitting surface 111a and further convert the optical signal into a pulse electrical signal.

[0034] It is understandable that in the process of converting high-energy rays into scintillation light, the energy of the scintillation light is less than that of the high-energy rays due to the conversion efficiency of the scintillation crystal 111, which is not conducive to the photodetector 20 sensing the scintillation light with lower energy. By setting the reflection of the reflective layer 112, more scintillation light is deflected and emitted toward the light-emitting surface 111a, so that the photodetector 20 can receive more light signals, thereby improving the sensitivity of the photodetector 20.

[0035] A plurality of scintillators 11 are linearly arranged to form a scintillator array 10 , and light emitting surfaces 111 a of two adjacent scintillators 11 are located at different sides of the scintillator array 10 .

[0036] The scintillators 11 fit together, thereby reducing the size of the scintillator array 10 , making the structure more compact, arranging more scintillators 11 in a unit volume, and reducing blind areas.

[0037] The light-emitting surfaces 111a of two adjacent scintillators 11 are located on opposite sides of the scintillator array 10, which reduces the possibility that the photodetector 20 corresponding to the scintillator 11 receives the light emitted by the light-emitting surface 111a of the adjacent scintillator 11, thereby reducing optical crosstalk; in addition, the distance between the photodetectors 20 respectively corresponding to the two adjacent scintillators 11 is increased, thereby reducing the electrical crosstalk between the two photodetectors 20.

[0038] The scintillator 11 in the scintillator array 10 of the embodiment of the present invention reflects the scintillation light through the reflective layer 112, and reflects the light to the light-emitting surface 111a, so that the photodetector 20 can better receive the light emitted from the light-emitting surface 111a; the adjacent scintillators 11 are arranged in a close proximity, so that the scintillator array 10 has a compact structure; the light-emitting surfaces 111a of two adjacent scintillators 11 are arranged on the opposite sides of the scintillator array 10, which reduces the possibility that the photodetector 20 receives light emitted from the light-emitting surface 111a that is not configured corresponding to it, thereby reducing optical crosstalk; by increasing the distance between the photodetectors 20, the possibility that the electrical signals generated by the photodetectors 20 interfere with each other is reduced, the noise signal of the photoelectric sensor is reduced, and the detection accuracy is improved.

[0039] The specific type of high-energy rays is not limited, such as X-rays.

[0040] The specific material of the scintillator crystal 111 is not limited, for example: bismuth germanate, lutetium silicate, lutetium yttrium silicate, lutetium gadolinium silicate, gadolinium silicate, yttrium silicate, barium fluoride, sodium iodide, cesium iodide, lead tungstate, yttrium aluminate, lanthanum bromide, lanthanum chloride, lutetium aluminum perovskite, lutetium aluminate and lutetium iodide, etc.

[0041] It can be understood that a light incident surface 112 a is provided on the scintillator 11 so that high-energy rays pass through the light incident surface 112 a and enter the scintillator crystal 111 .

[0042] It is understandable that the specific form of the light incident surface 112a is not limited.

[0043] For example, a portion of the outer surface of the scintillation crystal 111 not covered by the reflective layer 112 forms the light incident surface 112a. However, part of the scintillation light can be emitted from the non-light emitting surface 111a portion not covered by the reflective layer 112, thereby causing the loss of scintillation light.

[0044] For another example, the reflective layer 112 can transmit high-energy rays, so that a part of the reflective layer 112 serves as the light incident surface 112a of the scintillator 11. The outer surface of the scintillator crystal 111 except the light emitting surface 111a is covered by the reflective layer 112, thereby increasing the reflection area of ​​the reflective layer 112, thereby being able to reflect more scintillation light to the light emitting surface 111a, and reducing the loss of scintillation light.

[0045] The specific material for preparing the reflective layer 112 is not limited, such as aluminum.

[0046] The specific structural form of the reflective layer 112 is not limited. For example, a reflective coating is applied on the outer surface of the scintillation crystal 111 to form the reflective layer 112 ; or, for another example, a reflective film is attached to the outer surface of the scintillation crystal 111 to form the reflective layer 112 .

[0047] The specific process for preparing the reflective film is not limited, such as immersion plating, spray plating, vacuum evaporation and ion plating, etc. The specific process is selected according to actual needs.

[0048] The reflective layer 112 may be formed by a single layer of reflective film or a plurality of layers of reflective films, and the reflective film may be selected based on its thickness and reflection efficiency and in combination with actual needs.

[0049] In some embodiments, the scintillation light is emitted only from the light emitting surface 111a under the action of the reflective layer 112. The scintillation light is propagated along a preset route by adjusting the reflection angle of the reflective layer 112 to the scintillation light. Alternatively, the outer surface of the scintillation crystal 111 except the light emitting surface 111a is covered by the reflective layer 112. Thus, the scintillation light emitted by the scintillation crystal 111 is emitted from the light emitting surface 111a and transmitted to the photodetector 20, thereby increasing the intensity of the scintillation light received by the photodetector 20 and reducing noise.

[0050] It is understandable that there is only one light emitting surface 111 a so as to concentrate the scintillation light reflected by the reflective layer 112 and increase the intensity of the scintillation light received by the photodetector 20 .

[0051] It is understandable that the conversion efficiency of the scintillation crystal 111 in converting high-energy rays into scintillation light is limited, and therefore, part of the high-energy rays will irradiate the reflective layer 112 or be emitted from the light emitting surface 111 a .

[0052] In some embodiments, see Figure 2, a part of the outer surface of the scintillator 11 is incident on the light incident surface 112a of the scintillator 11 as high-energy rays, and in the plane projection perpendicular to the incident direction of the high-energy rays, the projection of the light exiting surface 111a is located outside the projection of the light incident surface 112a. This makes it impossible for the high-energy rays incident from the light incident surface 112a to directly pass through the scintillator crystal 111 and be emitted from the light exiting surface 111a, thereby preventing the photodetector 20 corresponding to the light exiting surface 111a from being directly irradiated by the high-energy rays, thereby reducing the probability of the photodetector 20 being damaged due to the irradiation of the high-energy rays and increasing the service life of the photodetector 20.

[0053] The specific orientation of the light-emitting surfaces 111a of two adjacent scintillators 11 is not limited, as long as the two meet the requirement of being on opposite sides. Figure 2 If the light emitting surface 111a of a scintillator 11 is located at the rear side, the light emitting surface 111a of another adjacent scintillator 11 may be located at the front side or the bottom side; if another adjacent scintillator 11 is located at both ends of the scintillator array 10, the light emitting surface 111a may be located at the left side or the right side.

[0054] It can be understood that, in the scintillator array 10 , the light emitting surfaces 111 a of the scintillators 11 are arranged according to a certain rule, so as to reduce the workload of preparing the scintillator array 10 .

[0055] In some embodiments, see Figure 2 The light emitting surfaces 111 a of two scintillators 11 separated by one scintillator 11 are located on the same side of the scintillator array 10 .

[0056] For example, see Figure 2 , the light emitting surface 111a of the first scintillator 11 from left to right along the first direction is located on the rear side, the light emitting surface 111a of the next scintillator after each scintillator 11 is also located on the rear side, and the light emitting surfaces 111a of the interval scintillators 11 are all located on the front side or the bottom side.

[0057] The two scintillators 11 with the light emitting surfaces 111a on the same side are separated by a distance of one scintillator 11, which reduces the possibility of optical and electrical crosstalk between the two. At the same time, the photodetectors 20 corresponding to the light emitting surfaces 111a on the same side are installed uniformly, thereby improving production efficiency and facilitating large-scale production.

[0058] In some embodiments, see Figure 2, a plurality of scintillators 11 are sequentially attached along the first direction to form a scintillator array 10, high-energy rays are incident on the scintillators 11 along the second direction, and each light-emitting surface 111a is located on two opposite sides of the scintillator array 10 along the third direction, wherein the first direction, the second direction and the third direction are orthogonal to each other. The possibility of high-energy rays incident on the scintillator 11 along the second direction and then being emitted from the light-emitting surface 111a is reduced, and the influence of high-energy rays on the photodetector 20 is weakened; each scintillator 11 in the scintillator array 10 is convenient for exciting scintillation light of different energies according to the different strengths of the received high-energy rays, thereby achieving the function of determining the position of the source of high-energy rays, and reducing the probability of shielding between two adjacent scintillators 11.

[0059] In some embodiments, see Figure 1 The scintillator crystal 111 and the scintillator 11 are both rectangular parallelepipeds, and the light-emitting surface 111a is at least a portion of an outer surface of the scintillator crystal 111. By setting it as a rectangular parallelepiped, on the one hand, it is convenient to process the scintillator crystal 111, which is conducive to improving production efficiency; on the other hand, it reduces the empty space between the scintillators 11 in the scintillator array 10, thereby improving space utilization.

[0060] In some embodiments where the scintillator 11 is a rectangular parallelepiped, see Figure 1 and Figure 2 The first surface 11a of the scintillator 11 is a light-entering surface 112a of the scintillator 11 as high-energy rays, and the second surface 11b adjacent to the first surface 11a is a light-emitting surface 111a. The first surface 11a and the second surface 11b are intersected with the third surface 11c, and the reflective layer 112 coated on the third surface 11c is attached to the adjacent scintillator 11. Thus, the light-entering surface 112a and the light-emitting surface 111a are perpendicular to each other, reducing the possibility of high-energy rays entering the scintillator 11 along the second direction and emitting from the light-emitting surface 111a. The reflective layer 112 is located between the scintillator crystals 111 of two adjacent scintillators 11, reducing the probability of mutual interference between the scintillation lights emitted by the two scintillator crystals 111.

[0061] It can be understood that in some embodiments where the scintillator 11 is a rectangular parallelepiped, the number of the third faces 11 c is two.

[0062] An embodiment of the present invention provides a scintillation detector, referring to Figures 3 to 5 The scintillation detector includes a photodetector 20, a light-transmitting layer 30 capable of transmitting scintillation light, and the scintillator array 10 described in any of the above embodiments, and the light-transmitting layer 30 is coupled between the photodetector 20 and the light-emitting surface 111a. The relative position between the photodetector 20 and the light-emitting surface 111a is kept stable, so that the photodetector 20 can receive the scintillation light emitted from the light-emitting surface 111a.

[0063] The specific material of the light-transmitting layer 30 is not limited, such as silicone oil, organic glass and organic plastic, etc., as long as the scintillation light emitted from the light-emitting surface 111 a can penetrate the light-transmitting layer 30 and be received by the photodetector 20 .

[0064] It can be understood that the light emitting surfaces 111a of two adjacent scintillators 11 are located on opposite sides of the scintillator array 10, making it difficult for the scintillation light penetrating the light-transmitting layer 30 to enter the adjacent light-transmitting layer 30 and be received by another photodetector 20, thereby reducing the optical crosstalk between the photodetectors 20.

[0065] It can be understood that the structure of the photoelectric sensor can better receive the flashing light emitted from the light emitting surface 111 a.

[0066] For example, see Figure 5 The structure of the photodetector 20 is as follows: the light emitting surface 111a is located within the range of the photosensitive surface 20a of the photodetector 20 for receiving the scintillation light. The photosensitive surface 20a completely covers the light emitting surface 111a, so that the photodetector 20 receives the scintillation light to the maximum extent, thereby improving the sensitivity of the photodetector 20.

[0067] In some embodiments, see Figure 4 and Figure 5 The structure of the photodetector 20 is as follows: the photosensitive surface 20a of the photodetector 20 for receiving scintillation light is located outside the irradiation range of the high-energy rays. This reduces the probability of the high-energy rays directly irradiating the photodetector 20 after passing through the scintillation crystal 111, thereby increasing the service life of the photodetector 20.

[0068] The photodetector 20 may be of any type, such as a photomultiplier tube, a multi-pixel photon counter, a silicon photodiode, an avalanche diode, an electron multiplying inductively coupled device, and the like.

[0069] The various embodiments / implementations provided in this application can be combined with each other without causing any contradiction.

[0070] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A scintillation detector, characterized in that: The scintillation detector comprises: A scintillator array, the scintillator array comprising a plurality of scintillators, the scintillators comprising scintillator crystals for absorbing high-energy rays and exciting scintillation light and a reflective layer for reflecting the scintillation light, a portion of the outer surface of the scintillator crystals being covered by the reflective layer, at least a portion of the outer surface of the scintillator crystals not covered by the reflective layer forming a light-emitting surface, the scintillator crystals and the scintillators being both rectangular parallelepipeds, a first surface of the scintillator serving as a light-incident surface for high-energy rays to enter the scintillator, a second surface adjacent to the first surface being the light-emitting surface, the first surface and the second surface being perpendicular to the third surface, and the reflective layer covering the third surface being in contact with the adjacent scintillator; A plurality of the scintillators are sequentially attached along a first direction to form the scintillator array, the high-energy rays are incident into the scintillators along a second direction, and the light-emitting surfaces are located on two opposite sides of the scintillator array along a third direction, wherein the first direction, the second direction and the third direction are orthogonal to each other; A photodetector, wherein the structure of the photodetector is as follows: the light emitting surface is located within the range of the photosensitive surface of the photodetector for receiving the scintillation light, and in a projection plane perpendicular to the third direction, the projection of the photodetector is located within the projection range of the scintillator; A light-transmitting layer capable of transmitting the scintillation light, wherein the light-transmitting layer is coupled between the photodetector and the light-emitting surface.

2. The scintillation detector according to claim 1, characterized in that The reflective layer can transmit high-energy rays, so that a partial area of ​​the reflective layer serves as a light incident surface of the scintillator.

3. The scintillation detector according to claim 1, characterized in that The flashing light is emitted only from the light emitting surface under the effect of the light reflecting layer.

4. The scintillation detector according to claim 1, characterized in that A portion of the outer surface of the scintillator is incident on the light incident surface of the scintillator as high-energy rays, and in a plane projection perpendicular to the incident direction of the high-energy rays, the projection of the light exiting surface is outside the projection of the light incident surface.

5. The scintillation detector according to claim 1, characterized in that The light emitting surfaces of two scintillators separated by one scintillator are located on the same side of the scintillator array.

6. The scintillation detector according to claim 1, characterized in that The photodetector is constructed as follows: a photosensitive surface of the photodetector for receiving the scintillation light is located outside the irradiation range of the high-energy rays.

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