CN-121995425-A - Scintillation detection system

CN121995425ACN 121995425 ACN121995425 ACN 121995425ACN-121995425-A

Abstract

The invention relates to a scintillation detection system, which belongs to the technical field of X-ray signal detection and solves the technical problems of weak anti-interference capability and low signal to noise ratio of X-ray detection. The incidence channel, the transmission channel, the reflection channel and the light collection channel are connected with each other to form a vacuum chamber. The scintillator center is located at the 4 channel central axis convergence point. The scintillator surface is perpendicular to the central axis of the light collection channel. The incident end of the optical fiber light transmission beam is connected with the light collecting channel, the emergent end of the optical fiber light transmission beam is connected with the photoelectric detector, and the photoelectric detector is positioned in the electromagnetic shielding box. The scintillator emits light to reach the surface of the incident end of the optical fiber light transmission beam, and the light intensity is uniformly distributed. The invention is used for low-intensity X-ray detection under strong background interference.

Inventors

MA GE
ZHANG ERMENG
XIA JINGTAO
CUI YE
TANG BO
HEI DONGWEI
YAN RUI
SHENG LIANG
LUO JIANHUI
LIU YONGTANG
WEI FULI
CHEN JUN

Assignees

西北核技术研究所

Dates

Publication Date: 20260508
Application Date: 20260113

Claims (10)

1. The scintillation detection system is characterized by comprising a plurality of detection unit strings, wherein each detection unit comprises an incident channel (1), a transmission channel (2), a reflection channel (3), a light collection channel (4), a scintillator (5), a scintillator bracket (6), an optical fiber light transmission beam (7), a photoelectric detector (8) and an electromagnetic shielding box (9); The light collecting device comprises an incidence channel (1), a transmission channel (2), a reflection channel (3) and a light collecting channel (4), wherein the incidence channel (1), the transmission channel (2), the reflection channel (3) and the light collecting channel (4) are connected with each other, the 4 channels form a vacuum chamber, the central axes of the 4 channels are coplanar, the central axes of the transmission channel (2) and the incidence channel (1) are coincident, the inner diameters of the transmission channel (2) and the incidence channel are identical, the reflection channel (3) is perpendicular to the incidence channel (1), the transmission channel (2), and the light collecting channel (4) and the transmission channel (2) form an angle of 45 degrees; The front end of the incidence channel (1) is connected with the tail end of a transmission channel (2) of the ray source or the front-stage detection unit through a flange (10); The tail end of the transmission channel (2) is connected with the front end of the incident channel (1) of the rear detection unit or the blind plate (11) through a flange (10); The scintillator (5) and the scintillator bracket (6) are positioned in the vacuum chamber, and the center of the scintillator (5) is positioned on the central axis convergence points of the 4 channels, and the surface of the scintillator (5) is vertical to the central axis of the light collecting channel (4) and is used for converting the radiation entering the incident channel (1) into visible light; The scintillator bracket (6) is fixedly connected to a flange (10) at the tail end of the transmission channel (2) and is used for fixing the scintillator (5); The blind plate (11) at the tail end of the transmission channel (2) is used for absorbing visible light transmitted by the scintillator (5); The blind plate (11) at the tail end of the reflection channel (3) is connected with the tail end of the reflection channel (3) through a flange (10) and is used for absorbing visible light reflected by the scintillator (5); the incident end of the optical fiber light transmission beam (7) is connected with the light collection channel (4), and the emergent end of the optical fiber light transmission beam is connected with the photoelectric detector (8) and is used for collecting visible light emitted by the scintillator (5) and transmitting the visible light into the photoelectric detector (8), and the photoelectric detector (8) is used for converting the visible light output by the optical fiber light transmission beam (7) into an electric signal and outputting the electric signal; the scintillator (5) emits light to reach the surface of the incident end of the optical fiber light transmission beam (7), and the light intensity is uniformly distributed; the photoelectric detector (8) is located in an electromagnetic shielding box (9), and the electromagnetic shielding box (9) is used for electromagnetic shielding of the photoelectric detector (8).
2. The scintillation detection system according to claim 1, wherein the incidence channel (1) and the transmission channel (2) are horizontally arranged, the reflection channel (3) is vertically arranged, the vacuum chamber is cylindrical in the horizontal direction, and the inner wall of the vacuum chamber is sandblasted.
3. The scintillation detection system according to claim 1, wherein the flange (10) is a vacuum-tight flange and the blind plate (11) is entirely blackened.
4. The scintillation detection system according to claim 1, wherein the incident end of the optical fiber light transmission beam (7) is connected to the end of the light collection channel (4) through a flange (10), and the connection between the light collection channel (4) and the optical fiber light transmission beam (7) is vacuum sealed by using ultraviolet quartz glass.
5. The scintillation detection system according to claim 1, wherein the scintillator (5) is an ultra-thin scintillator, the X-ray transmittance is less than 1E-4 by a coating process, and more than 99% of visible light in the radiation stream incident on the scintillator (5) enters the transmission channel (2) and the reflection channel (3).
6. The scintillation detection system according to claim 1, wherein the scintillator mount (6) comprises a cylinder wall (61), a compression ring (62); The cylinder wall (61) is of a cylindrical hollow structure, the front end face forms a 45-degree angle with the central axis of the transmission channel 2, and the tail end of the cylinder wall is fixedly connected with the flange (10) at the tail end of the transmission channel 2; blackening and thinning the blind plate (11) at the tail end of the transmission channel 2; the scintillator (5) is positioned between the cylinder wall (61) and the compression ring (62), the front end of the cylinder wall (61) is connected with the bottom surface of the scintillator (5), and the compression ring (62) is connected with the surface of the scintillator (5).
7. The scintillation detection system according to claim 1, characterized in that the optical fiber light-transmitting beam (7) is a beam-splitting structure; The optical fiber light transmission beam (7) is split at the emergent end; the optical fiber light transmission beam (7) is polymerized by adopting radiation-resistant quartz optical fibers, and the optical fibers are uniformly distributed in a beam splitting way.
8. The scintillation detection system according to claim 1, characterized in that the photodetector (8) is a high gain photomultiplier tube.
9. The scintillation detection system according to claim 1, wherein the electromagnetic shielding box (9) is a double-layer insulated metal box body, the electromagnetic shielding level is better than 70dB in full-welding process treatment, and a cable interface is arranged and is densely filled with metal cotton.
10. The scintillation detection system of claim 1 wherein the detection units are 2, or more than 2.

Description

Scintillation detection system Technical Field The invention belongs to the technical field of X-ray signal detection, and particularly relates to a scintillation detection system. Background The working principle of the scintillation detection system is that a scintillator is adopted as a conversion medium, the deposition energy in the particles after the particles enter the scintillator is converted into visible light to be emitted outwards, and the luminous intensity of the scintillator is measured through a photoelectric detector, so that the radiation intensity is measured. Because scintillators can respond to almost all types of incident particles by producing visible light, scintillation detection systems are widely used in various particle detection and radiation flux parameter diagnostics. In the field of X-ray detection, scintillators have a strong response capability to X-rays, and thus have been one of the mainstream X-ray detection means from the beginning. Also, because scintillators can produce visible light for almost all types of incident particles, scintillation detection systems often require a variety of particle screening techniques to be incorporated when measuring a particular particle in a mixed radiation stream. For X-rays, it is difficult to identify and separate their signals by particle screening methods. In addition, for some large-scale X-ray generating devices, the presence of high-intensity visible light in the output radiation stream can cause a strong disturbance to the photodetectors in the scintillation detection system, and therefore, it has been difficult to measure the X-rays in the mixed radiation stream using the scintillation detection system. Jiang Shilun, ning Jiamin, xu Rongkun, etc. disclose a scintillation detection system structural design, see Z-pinch X-ray radiation power scintillation detection system [ J ], atomic energy science technology 2006,40 (1): 96-99, a scintillator arrangement method with 45 degrees angle to the X-ray incidence direction and a detector arrangement method with a sensitive surface parallel to the scintillator plane are adopted to measure Z-pinch pulse X-rays, and a background detector is arranged at the end of the X-ray transmission direction to directly measure X-ray signals transmitted through the scintillator. The structure can effectively reduce the influence of visible light. Zhang Saiqun, huang Xianbin, li Jing, etc. disclose scintillation power meters [ J ], intense laser and particle beams, 2010,22 (4): 880-882, discussing two scintillation detection system structural designs, each employing a scintillator arrangement with a 45 degree angle to the X-ray incidence direction, and setting detectors aimed at the radiation incidence face and radiation transmission face of the scintillator, respectively, at a 90 degree angle to the radiation transmission direction for measuring the X-ray radiation power. However, the structural design mainly aims at the situations of relatively simple composition of radiation beams such as synchronous radiation and the like and natural small radiation interference, the influence of other radiation components in the mixed radiation flow on measurement is not fully considered in the measurement process, and the structural design has larger limitation in the measurement application of the mixed field X-ray intensity. Zhang Mei, peng Bodong, cheng Liang, etc. disclose a scintillator-optical fiber combined radiation detector gamma relative sensitivity study [ J ], nuclear technology 2009,22 (11): 867-871, which studies the performance of the scintillator-optical fiber combined detector, such as relative sensitivity, but does not develop a background interference separation and treatment method study and structural design. Disclosure of Invention In order to overcome the defects of weak anti-interference capability and low signal to noise ratio of X-ray detection, the invention provides a scintillation detection system. The technical scheme adopted for solving the technical problems is as follows: A scintillation detection system consists of a plurality of detection unit strings, wherein each detection unit comprises an incident channel, a transmission channel, a reflection channel, a light collection channel, a scintillator bracket, an optical fiber light transmission beam, a photoelectric detector and an electromagnetic shielding box. The incidence channel, the transmission channel, the reflection channel and the light collection channel are connected with each other, 4 channels of the incidence channel, the transmission channel, the reflection channel and the light collection channel form a vacuum chamber, and central axes of the 4 channels are coplanar. The central axis of the transmission channel is coincident with the central axis of the incidence channel, the inner diameter of the transmission channel is the same, the reflection channel is perpendicular to the incidence channel and the transmissi