CN102033239B - X-ray energy measuring system for accelerator - Google Patents

Abstract

The invention discloses an X-ray energy measuring system for an accelerator, comprising an X-ray dosage detection device, a collection device and a discriminator, wherein the X-ray dosage detection device comprises a plurality of detectors which are arranged at intervals in parallel, wherein signals of adjacent detectors are isolated so as to prevent signal crosstalk between each detector; a collection device; and a comparison device which includes a storage unit for storing a standard absorption curve of a standard energy accelerator on the X-ray dosage detection device, wherein the X-ray detection device is exposed through a series of standard energy accelerators so as to obtain a series of standard absorption curves corresponding to the energy stages of the series of standard energy accelerators; and a computation unit for executing comparison of the absorption curves with the standard absorption curves so as to determine the energy the accelerator to be detected.

Description

Accelerator X-ray energy measurement system

technical field

The invention relates to the field of energy and energy spectrum characteristic measurement of an accelerator X-ray source. More specifically, the present invention relates to a system for measuring the energy of accelerator X-rays. The invention adopts the principle of the transmission method, and uses the multi-layer detector group one-time exposure method to obtain the absorption curve of the accelerator dose in the group of detectors, supplemented by search and comparison of the standard energy accelerator dose absorption curve, and quickly and correctly determine the accelerator energy.

Background technique

Accelerator X-ray source is accelerated electrons to high energy by microwave acceleration tube or electrostatic acceleration tube. When electrons bombard the target material, due to bremsstrahlung radiation, a large number of X-rays appear symmetrically with the direction of electron movement. Average energy, energy spectrum, angular distribution, dose, etc. are related to electron energy, intensity, and thickness of target material properties. Accelerator X-ray sources are widely used in medical diagnosis and treatment, industrial radiation processing, radiation imaging flaw detection and inspection and scientific research. Since the energy, energy spectrum, angular distribution, dose and other characteristics of the accelerator X-ray source are important basis for the calculation and design of radiation protection, radiation physical effects, and radiation imaging indicators, the correct determination of the accelerator output X-ray energy (converted energy), energy spectrum Very important.

The output photon density of the accelerator X-ray source is very high. It is not easy to determine the energy and energy spectrum of the accelerator X-ray source by measuring the energy of a single photon with a spectrometer. However, it is currently commonly used to deduce the accelerator energy and energy spectrum by measuring the relatively simple dose attenuation law. The methods mainly include: 1. Dose half-value range attenuation measurement method, compared with the standard energy accelerator dose half-value range attenuation table; 2. Measuring the transmission dose attenuation law, using the Monte Cal program to simulate calculation and mathematical iteration to restore the accelerator ray energy 3. Search method by measuring dose decay curve and standard curve in three-dimensional water tank. Some of the above methods have a large and cumbersome measurement workload, and some need to borrow a large number of mathematical tools for derivation, which is difficult to use in the field and in product production.

Accordingly, there is a need for an improved accelerator X-ray energy measurement system, which can quickly and accurately measure the energy and/or spectral characteristics of accelerator X-rays.

Contents of the invention

The purpose of the present invention is to solve at least one aspect of the above-mentioned problems and defects existing in determining accelerator energy or energy spectrum characteristics in the prior art, for example, the measurement workload is heavy and cumbersome, a large number of mathematical tools need to be borrowed for derivation, and it is not easy to measure quickly and conveniently.

Accordingly, one of the objectives of the present invention is to provide an accelerator X-ray energy measurement system, which can quickly and accurately measure the energy of accelerator X-rays.

According to one aspect of the present invention, it provides a system for measuring the energy of accelerator X-rays, including: an X-ray dose detection device, which includes a plurality of detectors arranged in parallel and separated from each other, and the X-ray emitted from the accelerator to be detected X-rays are directed to multiple detectors to detect the dose of X-rays absorbed in each detector, and signal isolation is performed between adjacent detectors to prevent signal crosstalk between detectors; the collection device uses For collecting data corresponding to the dose of X-rays absorbed in each detector, and obtaining an absorption curve of X-rays absorbed dose on the X-ray dose detection device; and a comparison device for comparing the absorption curve with the standard energy The reference absorption curve of the accelerator on the X-ray dose detection device is compared to determine the energy of the accelerator to be detected, wherein the comparison device includes: a storage unit for storing standard energy in the X-ray dose of the accelerator a reference absorption curve on a detection device, wherein a series of reference absorption curves corresponding to energy levels of a series of standard energy accelerators are obtained by exposing a series of standard energy accelerators to said X-ray dose detection device; and a calculation unit , for performing comparison of the absorption curve with the reference absorption curve to determine the energy of the accelerator to be detected.

Preferably, the system for measuring the energy of accelerator X-rays also includes: a collimator, the X-rays emitted from the accelerator to be detected are collimated through the collimator, and then the collimated X-rays are guided to X-rays Multiple detectors on a dose detection device.

In a specific implementation manner, the collection device includes: a plurality of conversion elements, each of which is coupled to a corresponding detector, for converting the X-ray absorbed dose in each detector into an electrical signal; Each amplifier is coupled with a corresponding conversion element for linearly amplifying the electrical signal.

Specifically, the detector may be one of a solid scintillation detector, a gas detector, a semiconductor detector and a thermoluminescent sheet.

Preferably, the system for measuring the energy of accelerator X-rays also includes: a correction device, based on the difference in the parameter characteristics of each detector and amplifier, the original absorbed dose of the obtained X-rays on the X-ray dose detection device The absorption curve is corrected to obtain the absorption curve of the X-ray absorbed dose on the X-ray dose detection device.

Preferably, the system for measuring the energy of accelerator X-rays also includes: a collimator, used to collimate the X-rays emitted from the accelerator to be detected; Shielded from low-energy X-rays.

Specifically, the detector may be a solid scintillation detector, a gas detector, a semiconductor detector or a thermoluminescent film; and the conversion element may be a photosensitive element or a charge receiver.

Specifically, the storage unit may be a non-volatile memory, ROM, RAM or flash memory; the calculation unit may be a microcomputer or a microprocessor.

Compared with the existing technology, the present invention has the characteristics of high integration, simple operation, small scale of equipment, one-time exposure and fast determination of accelerator energy, etc., and is suitable for performance consistency inspection and calibration during mass production of accelerators and on-site accelerator energy calibration . In addition, the invention has wide adaptability, low production cost, convenient operation and use, and can be used for energy measurement and verification of accelerators for various purposes.

Description of drawings

FIG. 1 is a schematic diagram of a system for measuring energy of accelerator X-rays according to a specific embodiment of the present invention.

Fig. 2 is a schematic diagram of the composition and installation structure of an X-ray dose detection device according to a specific embodiment of the present invention, wherein Fig. 2A is a composition and structure diagram of an X-ray dose detection device in the form of a solid scintillation detector, and Fig. 2B is a diagram showing the installation structure between the solid-state scintillation detector, the collimator and the shield in FIG. 2A.

Fig. 3 is a flowchart of a method for measuring accelerator X-ray energy according to a specific embodiment of the present invention.

Detailed ways

The technical solutions of the present invention will be further specifically described below through the embodiments and in conjunction with the accompanying drawings. In the specification, the same or similar reference numerals designate the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the general inventive concept of the present invention, but should not be construed as a limitation of the present invention.

Referring to FIG. 1 , it shows a schematic diagram of a system for measuring the energy of accelerator X-rays according to a specific embodiment of the present invention. For reference, a system 100 for measuring the energy of X-rays of an accelerator 10 according to a specific embodiment of the present invention includes: an X-ray dose detection device 20, which includes a plurality of detectors 21 arranged in parallel and separated from each other , the X-rays emitted from the accelerator 10 to be detected are guided on a plurality of detectors 21 to detect the dose of X-rays absorbed in each detector 21; The data of the dose of X-ray, and obtain the absorption curve of the dose of X-ray absorbed on the X-ray dose detecting device 20; The reference absorption curve on the detection device 20 is compared to determine the energy of the accelerator 10 to be detected.

Referring to FIG. 2A , it shows a structural diagram of an X-ray dose detection device in the form of a solid scintillation detector. A plurality of detectors 21 are arranged side by side and substantially parallel to each other to form a detector group, wherein two adjacent detectors 21 are arranged to perform signal isolation, such as optical isolation, to prevent each detector 21 from crosstalk between signals. The detector can be in various forms, for example, it can be one of a solid scintillation detector, a gas detector, a semiconductor detector and a thermoluminescent sheet. Referring to Fig. 1, when the X-ray from the accelerator 10 to be detected is directed to the plurality of detectors 21 from the right to the left in Fig. The X-rays pass through some or all of the multiple detectors 21 in sequence, and are absorbed by each detector 21 with a corresponding dose. When X-rays from the accelerator 10 are injected into solid scintillation detectors 21, for example, the energy of X-rays is converted into light energy. isolation. Similarly, when using other types of detectors, such as gas detectors, when the X-rays from the accelerator 10 are incident on the gas detector 21, the energy of the X-rays is converted into electrical energy, in order to prevent each detector 21 To generate signal crosstalk, it is necessary to electrically isolate each detector 21 . Although, in the above-described embodiment, the X-rays from the accelerator 10 to be inspected are directed onto the plurality of detectors 21 in a direction substantially perpendicular to the stacking direction of the plurality of detectors 21, the present invention is not limited thereto, and the X-rays may be Incident to the plurality of detectors 21 at any suitable angle.

In the above embodiments, the standard energy accelerator is an existing or pre-provided energy accelerator that has been calibrated and used as a standard. After the X-ray dose detection device 20 is provided, a series of reference absorption curves corresponding to the energy levels of standard energy accelerators can be obtained by exposing a series of standard energy accelerators to the X-ray dose detection device 20 respectively. Referring to FIG. 2A, the collection device 30 includes: a plurality of conversion elements 31, each of which is coupled to a corresponding detector 21, for converting the dose absorbed by the X-rays in each detector 21 into an electrical signal; Each amplifier 32 is coupled to a corresponding conversion element 31 for linearly amplifying the electrical signal. The form of the conversion element 31 is determined according to the form of the detector. For example, when the detector is a solid-state scintillation detector or a thermoluminescent film, the conversion element is a photosensitive element, such as a silicon photodiode or a charge receiver.

When the X-rays from the accelerator 10 enter, for example, the solid-state scintillation detector 21, the energy of the X-rays is converted into light energy. Each conversion element 31 coupled with a corresponding one of the detectors 21 , such as a silicon photosensitive diode, is used to convert the dose absorbed by the X-rays in each detector 21 into an electrical signal. In a preferred implementation, each amplifier 32 is coupled to a corresponding conversion element 31 for linearly amplifying the electrical signal to obtain an amplified electrical signal that is easy to process.

Referring to FIG. 2B , it shows an installation structure diagram between the solid-state scintillation detector, the collimator 11 and the shielding body 12 in FIG. 2A . Similar to how the detector device in FIG. 1 is assembled into the cavity in the shielding body 12 along the direction of the arrow in the figure, in FIG. 2, the detector 20 in FIG. 2A is rotated 90 degrees to the right as shown in FIG. into the cavity in the shielding body 12, as shown in Figure 2B. In order to eliminate the interference of scattered X-rays, a collimator 11 is arranged at the front end of the system for measuring the energy of accelerator X-rays according to the present invention, and the X-rays sent from the accelerator 10 to be detected are collimated through the collimator 11, Then the collimated X-rays are directed to a plurality of detectors 21 on the X-ray dose detection device 20 . Specifically, through the collimation operation, the central positions of the plurality of detectors 21 of the X-ray dose detecting device 20 can be aligned with the beam center of the accelerator 10 .

Preferably, in order to further protect the external environment and shield the scattered low-energy X-rays from around the detection device, a shielding body 12 is provided outside the X-ray dose detection device 20 and the collimator 11 . In a specific embodiment, the shielding body 12 is made of a material with radiation protection function, such as heavy metal material lead, etc., and it is further provided with a cavity 13, and the X-ray dose detection device 20 is set to the cavity 13 of the shielding body 12 middle. Referring to FIG. 2B , the X-rays are collimated by the collimator 11 and then incident on each detector 21 of the X-ray dose detection device 20 . Each conversion element 31 coupled with a corresponding one of the detectors 21 , such as a silicon photosensitive diode, is used to convert the dose absorbed by the X-rays in each detector 21 into an electrical signal. The amplifier 32 coupled to the corresponding one of the conversion elements 31 linearly amplifies the electrical signal to obtain an electrical signal corresponding to the dose of X-rays absorbed in each detector 21 .

Based on the electrical signal data of each detector 21 corresponding to the dose absorbed by each detector 21 , the original absorption curve of the X-ray absorbed dose on the X-ray dose detection device can be obtained. The above-mentioned original absorption curve is obtained by connecting the data of electrical signals corresponding to the X-ray absorption dose in each detector 21 of each detector 21 into a curve. Further, in a preferred but non-limiting embodiment, the original absorption curve can also be completed by mathematical interpolation or Monte Cal simulation calculation.

Referring to Fig. 1, in a preferred embodiment, due to the existence of individual differences of each detector and subsequent amplifier parameters, in order to eliminate the influence of the individual differences of detector 21 and amplifier 32 parameters on the measurement results, it is necessary to The data obtained by the device 20, that is, the original absorption curve is corrected. As shown in Figure 1, the system for measuring the energy of accelerator X-rays also includes a correction device 50, based on the difference in the parameter characteristics of each detector and amplifier, the X-rays absorbed on the X-ray dose detection device obtained The original absorption curve of the dose is corrected to obtain the absorption curve of the dose absorbed by the X-ray dose detecting device. However, this embodiment is not limiting, and the individual differences of each detector may not be corrected, as long as the accelerator to be tested and the standard energy accelerator are exposed to the same X-ray dose detection device 20 .

In a preferred embodiment, referring to FIG. 1 , the system 100 for measuring the energy of accelerator X-rays further includes a comparison device 40, which includes: a calculation unit 41 for performing a comparison between the absorption curve and the reference absorption curve , to determine the energy of the accelerator to be detected. By comparing the measured absorption curve with the reference absorption curve, the energy and energy spectrum characteristics of the measured accelerator can be determined quickly and correctly. Preferably, the comparison device 40 further includes a storage unit 42 for pre-storing a reference absorption curve of a standard energy accelerator on the X-ray dose detection device. Specifically, the system is equipped with a series of reference absorption curves obtained by exposing the detector device 20 with a series of standard energy accelerators. Those skilled in the art should understand that by improving the accuracy of a series of reference absorption curves obtained by exposing the detector device 20 to the above-mentioned series of standard energy accelerators, the accuracy of determining the energy of the detected accelerator can be improved. For example, the energy sequences of the series of standard energy accelerators used are 0.5Mev, 1Mev, 1.5Mev, 2Mev..., and the difference is 0.5Mev; if the energy sequences of the series of standard energy accelerators used are 0.1Mev, 0.2Mev, 0.3Mev, 0.4Mev, 0.5Mev..., the step difference is 0.1Mev, then correspondingly, the accuracy of the reference absorption curve of the standard energy accelerator on the X-ray dose detection device is increased by 5 times , then the accuracy of the accelerator energy obtained by comparing the measured absorption curve with the reference absorption curve is also increased by 5 times.

Preferably, the reference absorption curves of standard energy accelerators for each energy segment with respect to the above-mentioned detector device 20 can be completed by means of mathematical interpolation or Monte Carlo simulation calculation.

In the specific embodiment shown in FIG. 1 , the storage unit 42 may be a non-volatile memory, ROM, RAM or flash memory, and the calculation unit 41 may be a microcomputer or a microprocessor.

A method for measuring accelerator X-ray energy according to a specific embodiment of the present invention will be described below with reference to FIGS. 1-3 . Referring to Fig. 3, the method for measuring accelerator X-ray energy according to a specific embodiment of the present invention includes the steps of: providing an X-ray dose detection device 20, which includes a plurality of detectors 21 (S1) parallel to each other and isolated from each other; The detected X-rays sent by the accelerator 10 are guided to a plurality of detectors 21 of the X-ray dose detection device 20 (S2); the dose of the X-rays absorbed in each detector 21 is collected, and the X-rays are obtained in the X-ray dose The absorption curve (S3) of the absorbed dose on the detection device 20; and comparing the absorption curve with the reference absorption curve of a standard energy accelerator on the X-ray dose detection device 20 to determine the intensity of the accelerator 10 to be detected. Energy (S5).

As previously mentioned, in step S1, the detector 21 may include one of a solid scintillation detector, a gas detector, a semiconductor detector and a thermoluminescent film, and each detector 21 collects X-rays independently in each detector absorbed dose. In step S2, the X-rays emitted from the accelerator 10 to be detected are directed to the plurality of detectors 21 of the X-ray dose detection device 20, such as to make the central position of the plurality of detectors 21 of the X-ray dose detection device 20 Align with the beam center of the accelerator 10. In a preferred embodiment, the X-rays emitted from the accelerator to be detected can be collimated, and then the collimated X-rays can be directed to multiple detectors of the X-ray dose detecting device.

In the collection step S3, as mentioned above, each conversion element 31 coupled to a corresponding one of the detectors 21, such as a silicon photodiode, is used to convert the dose of X-ray absorbed in each detector 21 into an electrical signal. Preferably, the electrical signal is linearly amplified by the corresponding amplifier 32, so as to obtain an amplified electrical signal that is convenient for processing. Based on the electrical signal data of each detector 21 corresponding to the X-ray absorbed dose in each detector 21 , the original absorption curve of the X-ray absorbed dose on the X-ray dose detection device can be obtained.

Due to the existence of individual differences in the parameters of each detector and subsequent amplifiers, in one embodiment, in order to eliminate the influence of individual differences in the parameters of the detector 21 and the amplifier 32 on the measurement results, it is necessary to analyze the data obtained from the detector device 20 , that is, to correct the original absorption curve. In step S4, in one embodiment, on the contact of obtaining the original absorption curve of the X-ray absorbed dose on the X-ray dose detection device 20, based on the difference in the parameter characteristics of each detector 21, the X-ray The original absorption curve of the X-ray absorbed dose on the X-ray dose detection device is corrected to obtain the absorption curve of the X-ray absorbed dose on the X-ray dose detection device. In another embodiment, when the amplifier 32 is used to amplify the electrical signal obtained by the conversion element 31, based on the difference in the parameter characteristics of each amplifier 32, the absorption of X-rays on the X-ray dose detection device 20 obtained The original absorption curve of the dose is corrected to obtain the absorption curve of the dose absorbed by the X-ray dose detection device 20 .

It should be noted that the correction step is mainly to correct the data deviation caused by individual differences in parameters of each detector and subsequent amplifiers, which is not necessary. In addition, although the calibration steps in the foregoing embodiments of the present invention are performed by the calibration device 50, this cannot be construed as a limitation of the present invention, for example, manual calibration can also be performed by an operator.

In the comparing step S5, the absorption curve is compared with a reference absorption curve of a standard energy accelerator on the X-ray dose detection device 20 to determine the energy of the accelerator 10 to be detected. In a specific embodiment, the reference absorption curve of a standard energy accelerator on the X-ray dose detection device 20 is provided in advance, and is sent to the calculation unit 41; The absorption curve of the dose absorbed on the detection device is input into said computing unit 41 in order to perform a comparison of said absorption curve with a reference absorption curve. As mentioned above, in a specific embodiment, the reference absorption curve of the standard energy accelerator on the X-ray dose detection device can be pre-stored in the storage unit 42, for example, it can be a non-volatile memory, ROM, RAM or flash memory . A calculation unit 41, such as a microcomputer or a microprocessor, is used to compare the absorption curve with a reference absorption curve to determine the energy of the accelerator to be detected. By comparing the measured absorption curve with the reference absorption curve, the energy and energy spectrum characteristics of the measured accelerator can be determined quickly and correctly.

In addition, although the comparison step in the foregoing embodiments of the present invention is performed by the comparison device 40, specifically, the comparison device 40 includes: a calculation unit 41, which is used to compare the absorption curve with a reference absorption curve to determine The energy of the accelerator to be detected. Preferably, the comparison device 40 further includes a storage unit 42 for pre-storing a reference absorption curve of a standard energy accelerator on the X-ray dose detection device. However, this cannot be construed as a limitation to the present invention. For example, the above-mentioned storage unit 42 can also be replaced by a reference absorption curve in physical form, and the above-mentioned comparison operation can also be completed by the operator.

In addition, according to the above-mentioned technical scheme, all schemes that integrate multiple detectors, measure the accelerator dose absorption curve with one-time or multiple exposures, and determine the energy of the accelerator by comparing with a series of reference curves belong to the scope of the present invention. protected range.

In addition, according to the above-mentioned technical scheme, different detector types are used to form a detector group, the accelerator dose absorption curve is obtained through one-time or multiple exposures, and the energy of the accelerator is determined by comparing with a series of reference curves. protection scope of the present invention.

While certain embodiments of the present general inventive concept have been shown and described, it will be understood by those of ordinary skill in the art that changes may be made to these embodiments without departing from the principles and spirit of the present general inventive concept. The scope is defined by the claims and their equivalents.

Claims (6)

1. system of be used for measuring the energy of accelerator X ray comprises:

The x-ray dose sniffer, it comprises a plurality of detectors that are parallel to each other and isolate setting, the X ray that sends from accelerator to be detected is directed on a plurality of detectors perpendicular to the stack direction of a plurality of detectors substantially, X ray pass successively in a plurality of detectors partly or entirely, to survey the dosage of the X ray that absorbs in each detector, wherein carry out signal between the adjacent detector and isolate, to prevent producing signal cross-talk between each detector;

Gathering-device, for the data of the dosage of collecting the X ray that absorbs corresponding to each detector, and the absorption curve of acquisition X ray absorbed dose on described x-ray dose sniffer; And

Comparison means is used for that the benchmark absorption curve on described x-ray dose sniffer compares with described absorption curve and standard energy accelerator, and with the energy of definite described accelerator to be detected, wherein said comparison means comprises:

Storage unit, be used for the benchmark absorption curve of storage standards energy accelerator on described x-ray dose sniffer, wherein by series of standards energy accelerator is exposed to described x-ray dose sniffer, obtain a series of benchmark absorption curves corresponding with the energy rank of series of standards energy accelerator; With

Computing unit be used for to carry out that described absorption curve and described benchmark absorption curve are compared, with the energy of definite described accelerator to be detected;

Wherein carry out electricity between the adjacent detector and isolate, to prevent that producing electric signal between each detector crosstalks.

2. the system for the energy of measuring the accelerator X ray according to claim 1 also comprises:

Collimating apparatus is used for the X ray that sends from accelerator to be detected is collimated; And

Shield is used for shielding from the scattering low energy X ray around the sniffer.

3. the system for the energy of measuring the accelerator X ray according to claim 1 and 2, wherein said gathering-device comprises:

A plurality of conversion elements, each conversion element and corresponding detector coupling are used for converting X ray to electric signal at each detector absorbed dose; And

A plurality of amplifiers, each amplifier and corresponding conversion element coupling are used for electric signal is carried out linearity amplification.

4. the system for the energy of measuring the accelerator X ray according to claim 3, wherein:

Described detector is gas detector.

5. the system for the energy of measuring the accelerator X ray according to claim 4 also comprises:

Means for correcting, difference based on the parameter characteristic of each detector and amplifier, original absorption curve to X ray absorbed dose on described x-ray dose sniffer of obtaining is proofreaied and correct, to obtain the absorption curve of X ray absorbed dose on described x-ray dose sniffer.

6. the system for the energy of measuring the accelerator X ray according to claim 1, wherein:

Described storage unit is nonvolatile memory or RAM;

Described computing unit is microcomputer or microprocessor.

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