Water ionization-based radiation dose measurement method, and radiation dosimeter

Abstract

A water ionization-based radiation dose measurement method, comprising the following operations: using a light guide fluid to construct a measurement region; radiating a radiation beam to the measurement region, such that the light guide fluid is ionized to generate an ionization product; transmitting an optical signal to the measurement region, wherein in the measurement region, at least part of the optical signal is absorbed by the ionization product, and the unabsorbed optical signal is emitted from the measurement region; acquiring the optical signal emitted from the measurement region to form a light intensity; on the basis of a mapping relationship between light intensities and radiation doses, converting a two-dimensional image of light intensity distribution into a two-dimensional image of dose distribution; and using the two-dimensional image of dose distribution to perform three-dimensional image reconstruction, so as to obtain an image representing the situation of distribution of the radiation doses absorbed by the measurement region, the light guide fluid being pure water or an aqueous solution. The measurement method exhibits radiation resistance and high spatial resolution, and can efficiently and reliably monitor multi-dimensional dynamic distribution of radiation doses in measurement regions.

Description

Radiation dose testing method based on water ionization and radiation dose meter TECHNICAL FIELD

[0001] The present application belongs to the technical field of radiation dose measurement, and particularly relates to a radiation dose testing method based on water ionization and a radiation dose meter. BACKGROUND

[0002] Radiotherapy is one of the three major means of treating tumors, and its purpose is to kill tumor cells as much as possible and effectively protect surrounding normal tissues and important organs. In order to achieve this purpose, modern radiotherapy technology is developing towards more refined and customized treatment plans, and more accurate and complex treatment implementation. This trend is particularly evident in new technologies such as intensity-modulated radiotherapy (IMRT), stereotactic ablative radiotherapy (SABR), proton and heavy ion therapy, microbeam radiotherapy, and FLASH radiotherapy. These radiotherapy technologies produce complex dose distributions that match the patient's anatomy and tumor shape, posing challenges for dose measurement. For example, the ultra-high dose rate irradiation produced in FLASH radiotherapy, proton and heavy ion therapy requires radiation-resistant dosimeters, and the small field irradiation in microbeam radiotherapy and stereotactic ablative radiotherapy requires high spatial resolution. In particular, all radiotherapy methods require accurate measurement of the three-dimensional distribution of the dose.

[0003] Currently, conventional dose measurement methods such as two-dimensional and three-dimensional detector arrays, electronic portal imaging devices (EPID) can only provide sparse three-dimensional data, and the only 3D gel dosimeter on the market has a long processing time and is a disposable consumable, limiting its widespread use in clinical settings. The three-dimensional dose detection methods based on Cerenkov radiation light and fluorescence being developed have not yet been commercialized due to their own defects such as energy threshold, ionization quenching, afterglow effect, and irradiation damage.

[0004] The prior art CN113260878A provides a radiation dose meter based on a resonant cavity and an optical fiber, which detects the dose by detecting the absorption of hydrated electrons in a water solution to an external optical signal. However, this device can only measure the dose at a certain point, and is more suitable for real-time monitoring of the radiation dose in the human body during radiotherapy, and cannot provide the three-dimensional spatial distribution of the dose.

[0005] In summary, the development of modern radiotherapy technology and its safe use require an accurate, practical and economical 3D dose measurement method with high spatial resolution and radiation resistance. SUMMARY

[0006] In order to realize efficient and reliable multi-dimensional detection of radiation dose, the application provides a radiation dose testing method based on water ionization and a radiation dosimeter.

[0007] According to a first aspect of the application, a three-dimensional radiation dose detection method based on water ionization is provided, comprising the following operations: constructing a detection area by using a light-guiding fluid, radiating a radiation beam to the detection area so that the light-guiding fluid is ionized to generate ionization products, making an optical signal incident on the detection area, at least a part of the optical signal being absorbed by the ionization products in the detection area, the optical signal not absorbed being emitted from the detection area, collecting the optical signal emitted from the detection area to form a light intensity distribution two-dimensional image, converting the light intensity distribution two-dimensional image into a dose distribution two-dimensional image based on a mapping relationship between light intensity and radiation dose, and reconstructing a three-dimensional image by using the dose distribution two-dimensional image, so that the three-dimensional image obtained thereby represents a three-dimensional distribution of the radiation dose absorbed by the detection area; wherein the light-guiding fluid is pure water or an aqueous solution.

[0008] The detection principle of the above-mentioned radiation dose detection method is that the light-guiding fluid is ionized by the radiation beam, and the ionization products generated thereby absorb the optical signal, so that the light intensity of the optical signal changes before and after entering the detection area. Based on the fact that different regions in the detection area have different dose distribution conditions, the optical signal emitted from the detection area will form a light intensity distribution two-dimensional image with different light intensity levels, and the light intensity distribution two-dimensional image can reflect the deposition of the radiation dose in the detection area. Based on the above-mentioned detection principle, the application further controls the optical path length in the detection area, so that the light intensity distribution two-dimensional image has excellent imaging quality, and the radiation dose distribution conditions in a wide dose range can be collected in the form of a light intensity distribution two-dimensional image. The three-dimensional model obtained by three-dimensional reconstruction based on the two-dimensional image can accurately reflect the three-dimensional distribution of the radiation dose, thereby realizing real-time and highly reliable three-dimensional radiation dose detection. In addition, the raw material of water or an aqueous solution is easy to obtain, and the cost is relatively low and easy to replace. Using water or an aqueous solution as the light-guiding fluid can reduce the detection cost, and the physicochemical indicators of the light-guiding fluid can be flexibly adjusted according to actual conditions, so that different testing requirements can be well met. In addition, the dose can be detected by using an optical method, which can realize high time and spatial resolution. In summary, the radiation dose detection method based on water ionization provided by the application has excellent time resolution and spatial resolution, and can efficiently and reliably monitor the multi-dimensional dynamic distribution of the radiation dose in the detection area.

[0009] Preferably, the optical path length in the detection area is 3 cm to 2 m.

[0010] Preferably, the ionized products include at least one of hydrogen ions, hydroxide ions, hydrated hydrogen ions, hydrated hydroxide ions, ionized water molecules, excited electrons, hydrated electrons, hydrogen radicals, hydroxyl radicals, excited water molecules, hydrogen gas, and hydrogen peroxide.

[0011] Preferably, the ionized products include hydrated electrons. Based on the three-dimensional radiation dose detection method proposed in the present solution, the lifetime of the hydrated electrons can be regulated within the range of 0.5 μs - 660 μs in the application process, which can flexibly adapt to different detection requirements. In order to balance the detection efficiency and the reliability of the detection results, preferably, in the application process of the three-dimensional radiation dose detection method, the lifetime of the hydrated electrons belongs to the range of 1 μs - 100 μs.

[0012] Preferably, the wavelength range of the light signal belongs to 100 nm~2 μm.

[0013] Preferably, the wavelength range of the light signal belongs to 400 nm~1000 nm. Further controlling the wavelength of the light signal within the above range, the absorption amount of the hydrated electrons to the first light signal presents a linear relationship with the radiation dose in a relatively wide dose range and dose rate range (dose dynamic range 0.5 mGy~500 Gy, dose rate dynamic range 0.1 cGy / s~1×10 10 Gy / s), so that the optical intensity two-dimensional image with obvious light and dark partitions can be obtained in the detection area due to the different distribution amounts of the radiation dose in different local parts, the resolution of the optical intensity two-dimensional image is improved, and the imaging quality of the optical intensity two-dimensional image is better improved.

[0014] Preferably, the wavelength range of the light signal belongs to 600 nm~800 nm.

[0015] Preferably, the pH of the light-guiding fluid is 5~12. According to the actual situation, if it is necessary to regulate the pH of the light-guiding fluid, one or a combination of the following materials can be selected: acidic materials such as hydrochloric acid (HCl), nitric acid (HNO3), sulfuric acid (H2SO4), etc.; basic materials such as sodium hydroxide (NaOH), potassium hydroxide (KOH), ammonia (NH3·H2O), etc.; buffer solutions such as acetic acid / sodium acetate buffer solution, phosphate buffer solution, bicarbonate buffer solution, etc.; other pH regulators such as boric acid, ethylenediaminetetraacetic acid (EDTA).

[0016] Preferably, the pH of the light-guiding fluid is 6~8.5. Within the above pH range, the hydrated electrons have higher stability, so that the imaging quality of the optical intensity two-dimensional image is improved.

[0017] Preferably, the light-guiding fluid contains sodium sulfite.

[0018] Preferably, the light signal is a parallel beam, a quasi-parallel beam, or a conical beam, which can better realize 3D reconstruction of the spatial distribution of the dose.

[0019] Preferably, the light intensity distribution two-dimensional images are collected from different positions respectively, and the time difference between the triggering of the beam pulse and the collection of the light intensity distribution two-dimensional image in any one collection process is 10 ns to 1001 ms.

[0020] Preferably, the time difference between the triggering of the beam pulse and the collection of the light intensity distribution two-dimensional image in any one collection process is 500 μs to 1001 ms.

[0021] According to a second aspect of the present application, a radiation dose testing method based on water ionization is provided, comprising the following operations: constructing a detection area by using a light guide fluid, the light guide fluid comprising at least one of pure water and a water solution; incidenting a light signal to the detection area to collect the light intensity of the light signal to obtain a background signal; radiating a radiation beam to the detection area to cause ionization of the light guide fluid to generate ionization products, and again incidenting the light signal to the detection area to collect the light intensity of the light signal to obtain a radiation signal; taking the variation of the background signal and the radiation signal value as an ionization absorption signal, and calculating the radiation dose absorbed by the detection area based on the mapping relationship between the ionization absorption signal and the radiation dose.

[0022] Preferably, the above-mentioned radiation dose testing method based on water ionization comprises the following operations: determining a first detection area, incidenting a light signal to the first detection area to collect the light intensity of the light signal to obtain a first background signal; radiating a first radiation beam to the first detection area to cause ionization of the light guide fluid to generate ionization products, and again incidenting the light signal to the first detection area to collect the light intensity of the light signal to obtain a first radiation signal; taking the variation of the first background signal and the first radiation signal as a first ionization absorption signal; determining a second detection area, the second detection area being not completely coincident with the first detection area, incidenting a light signal to the second detection area to collect the light intensity of the light signal to obtain a second background signal; radiating a second radiation beam to the second detection area to cause ionization of the light guide fluid to generate ionization products, the second radiation beam having the same dose as the first radiation beam, and again incidenting the light signal to the second detection area to collect the light intensity of the light signal to obtain a second radiation signal; taking the variation of the second background signal and the second radiation signal as a second ionization absorption signal; deducting the second ionization absorption signal from the first ionization absorption signal to obtain a light intensity variation distribution signal, and calculating the radiation dose absorbed by the area between the first detection area and the second detection area based on the mapping relationship between the light intensity variation distribution signal and the radiation dose.

[0023] Preferably, the ionized products include at least one of hydrogen ions, hydroxide ions, hydrated hydrogen ions, hydrated hydroxide ions, ionized water molecules, excited secondary electrons, hydrated electrons, hydrogen radicals, hydroxyl radicals, excited state water molecules, hydrogen gas, and hydrogen peroxide.

[0024] Preferably, the wavelength of the incident light is 400 nm to 1600 nm.

[0025] Preferably, the incident light is near-infrared light. The use of near-infrared light can make the wavelength range completely distinguishable from the wavelength of Cerenkov light, so that the wavelength range of the incident light can be selectively collected during detection, effectively avoiding the interference of Cerenkov light on the detection result.

[0026] Preferably, the ionized products are hydrated electrons. Hydrated electrons can effectively absorb near-infrared light, so that when the incident light is near-infrared light and the ionized products are hydrated electrons, the change in light intensity of the incident light before and after the ionized products are generated can reliably reflect the radiation dose in the detection area.

[0027] Preferably, the pH of the light-guiding fluid is 6 to 8.5.

[0028] Preferably, the light-guiding fluid includes at least one of water and a sodium sulfite aqueous solution. The sodium sulfite aqueous solution has a radiation resistance effect.

[0029] Preferably, the concentration of sodium sulfite in the sodium sulfite aqueous solution is 0.5 mmol / L to 30 mmol / L. When the concentration of sodium sulfite in the sodium sulfite aqueous solution reaches the above range, the lifetime of the ionized products can be effectively prolonged, thereby improving the reliability of the optical signal detection.

[0030] According to a third aspect of the present application, a radiation dosimeter is provided, which includes: a water tank, the water tank being provided with an inner cavity for accommodating a light-guiding fluid, the light-guiding fluid being pure water or an aqueous solution, a detection area being constructed by the light-guiding fluid, and the optical path length in the detection area being 3 cm to 2 m; a light source, the light source being configured to emit an optical signal to the detection area, at least a part of the optical signal being configured to be absorbed by ionized products, and the unabsorbed optical signal being emitted from the detection area; and an image acquisition module, the image acquisition module being configured to acquire a two-dimensional image of the light intensity distribution formed by the optical signal emitted from the detection area. The dosimeter can acquire the two-dimensional image of the light intensity distribution when applied.

[0031] The above-mentioned radiation dosimeter has the following advantages:

[0032] (1) high spatial resolution, the spatial resolution can reach the micron level; high temporal resolution, the temporal resolution can reach the microsecond level; the distribution of the radiation dose can be dynamically monitored in real time during the operation;

[0033] (2) good accuracy and precision, wherein the accuracy can be within 3% and the precision can be within 1%;

[0034] (3) high physical stability of the device, and the device is less affected by temperature, humidity, pressure and radiation.

[0035] Preferably, the inner cavity of the water tank comprises an incident light side and an exit light side, and the distance between the incident light side and the exit light side is 3 cm to 40 cm.

[0036] Preferably, the material of the water tank is at least one of quartz glass, crystal glass, acrylic, polystyrene, polyethylene, polycarbonate or PET plastic (polyethylene terephthalate).

[0037] Preferably, the material of the water tank is at least one of quartz glass, crystal glass or acrylic.

[0038] Preferably, the material of the water tank is quartz glass.

[0039] Preferably, the thickness of the tank wall of the water tank is 5 mm to 3 cm.

[0040] Preferably, the thickness of the tank wall of the water tank is 5 mm.

[0041] Preferably, the radiation dosimeter further comprises an image processing module, which is configured to perform three-dimensional image reconstruction based on the two-dimensional image of light intensity distribution. When the radiation dosimeter itself also comprises an image processing module with three-dimensional image reconstruction function, it can quickly perform three-dimensional image reconstruction after the two-dimensional image of light intensity distribution is collected, which is conducive to realizing real-time detection of dose distribution, and in addition, also makes the integration of the radiation dosimeter higher.

[0042] Preferably, the radiation dosimeter further comprises a rotating driving device configured to cause rotational displacement of the light source and the image acquisition module. By using the rotating driving device to cause rotational displacement of the light source and the image acquisition module, the radiation dose distribution of the test region in different directions can be obtained, and the three-dimensional image reconstruction can be more comprehensive by using the radiation dose distribution in different directions, and a more reliable radiation dose three-dimensional distribution can be obtained.

[0043] Preferably, the radiation dosimeter further comprises a slide configured to linearly move the water tank, the light source and / or the image acquisition module along the slide. By linearly sliding the water tank along the slide, the two-dimensional radiation dose distribution of different interfaces in the radiation field can be obtained, and the spatial resolution can also be adjusted by adjusting the moving distance.

[0044] Preferably, the light source, the water tank and the image acquisition system are sequentially arranged along the slide and linearly arranged.

[0045] Preferably, a moving platform is installed on the slide and can linearly slide along the slide, and the light source, the water tank and the image acquisition system are installed on the moving platform.

[0046] Preferably, the water tank contains pure water and / or sodium sulfite solution.

[0047] Preferably, the water tank further comprises a transition zone, which is arranged adjacent to the inner cavity along the extension direction of the slide; the material constituting the transition zone satisfies the following (a) or (b): a. the material constituting the transition zone does not produce ionization products when receiving the radiation beam; b. when receiving the same dose of radiation beam, the ionization products produced by the material constituting the transition zone have a shorter lifetime than the ionization products produced by the material constituting the detection area. The provision of the transition zone makes it possible to obtain a 2D dose distribution by subtraction.

[0048] Preferably, the water tank is arranged in one of the following ways: transition zones are arranged on both sides of the inner cavity along the extension direction of the slide; or, a transition zone is arranged on one side of the inner cavity along the extension direction of the slide.

[0049] Preferably, the material constituting the transition zone comprises at least one of quartz glass, crystal glass, acrylic, polystyrene, polyethylene, polycarbonate, polyethylene terephthalate and pure water, and the light guide fluid is sodium sulfite aqueous solution.

[0050] Preferably, a double-telecentric lens is arranged on the light exit side of the light source and / or the light entrance side of the image acquisition module. By arranging the double-telecentric lens on the light exit side of the light source, only the parallel light portion in the incident light can be retained by the double-telecentric lens. By arranging the double-telecentric lens on the light entrance side of the image acquisition module, it can be ensured that the received light signal is parallel light. The introduction of the double-telecentric lens can eliminate perspective errors and improve imaging quality.

[0051] According to a fourth aspect of the present application, a radiation dosimeter is provided, which comprises: a water tank, the water tank being provided with an inner cavity for containing a light guide fluid, the light guide fluid being pure water or an aqueous solution, and a detection area being constructed with the light guide fluid; a light source, the light source being configured to emit a light signal to the detection area, the light signal being configured to be at least partially absorbed by ionization products, and the unabsorbed light signal being emitted from the detection area; a detector, the detector being configured to detect the light intensity of the light signal and convert the light intensity signal into an electrical signal; an optical fiber, the optical fiber comprising an incident optical fiber and an exit optical fiber, the incident optical fiber being configured to guide the light signal from the light source to the detection area, and the exit optical fiber being configured to guide the light signal from the detection area to the detector; and a signal processing unit, the signal processing unit being configured to calculate the radiation dose according to the electrical signal.

[0052] Preferably, the radiation dose meter further comprises an X-axis movement system for guiding the detector to move linearly along an X direction, a Y-axis movement system for guiding the detector to move linearly along a Y direction, and a Z-axis movement system for guiding the detector to move linearly along a Z direction, wherein the X direction, the Y direction and the Z direction are perpendicular to each other. The detector can be positioned flexibly in a three-dimensional space by means of the X-axis movement system, the Y-axis movement system and the Z-axis movement system, so as to measure the radiation dose of different point regions in the three-dimensional space of the detection region flexibly.

[0053] Preferably, the radiation dose meter further comprises a base, the X-axis movement system and the Y-axis movement system are arranged on the base, and the water tank is arranged on the X-axis movement system and the Y-axis movement system, so that the X-axis movement system can guide the water tank to move linearly along the X direction, and the Y-axis movement system can guide the water tank to move linearly along the Y direction.

[0054] Preferably, the Z-axis movement system is arranged in the interior of the water tank, and the Z-axis movement system comprises a carrier, which can move linearly along the Z direction. The radiation dose meter further comprises a positioning assembly, and the optical fiber is arranged on the carrier through the positioning assembly.

[0055] Preferably, the positioning assembly comprises an optical fiber clamp, and the incident optical fiber and the outgoing optical fiber are fixed by the optical fiber clamp so that the light emitting end of the incident optical fiber and the light receiving end of the outgoing optical fiber are opposite and spaced apart.

[0056] Preferably, the radiation dose meter further comprises a filter, which is arranged on the light receiving side of the detector. BRIEF DESCRIPTION OF DRAWINGS

[0057] Fig. 1 is a schematic diagram of the basic structure of the radiation dose meter provided in embodiments 1, 2, 3 and 4. In Fig. 1, the black solid lines from left to right represent the light path propagation path of the light signal emitted by the light source 1 in the above-mentioned components, and the arrow below the rotating platform 5 represents the direction of rotation of the rotating platform 5.

[0058] Fig. 2 is a top view of the radiation dose meter in the case of using a total reflection mirror 7 in embodiment 1. The arrow in Fig. 2 represents the light path propagation path of the light signal.

[0059] Fig. 3 shows the optical response characteristic curves of the light guide fluid with different concentrations of sodium sulfite under the action of radiation in embodiment 4. Fig. 3a is a curve of the absorbance of the light guide fluid in each experimental group changing with time, and Fig. 3b is a curve of the normalized light intensity in the detection region of each experimental group changing with time.

[0060] Figure 4 shows the light signal response curves of the light-guiding fluid under different pulse radiation doses in Example 4, wherein Figure 4a is a curve of absorbance changing with time, and Figure 4b is a curve of normalized light intensity changing with time;

[0061] Figure 5 shows the calibration curve between the radiation dose and the maximum absorbance value measured by a photodetector (PD) using the EBT-XD irradiated color-changing film;

[0062] Figure 6 shows the radiation dose distribution measured by the radiation dosimeter in Example 4, wherein Figure 6a is a hydrated electron image captured by a CMOS camera, and Figure 6b is a cross-sectional dose distribution diagram obtained based on the reconstructed multi-angle two-dimensional image;

[0063] Figure 7 is a radiation dose distribution diagram measured using the EBT-XD irradiated color-changing film, wherein Figure 7a is a radiation dose distribution image, and Figure 7b is a dose distribution contour map of the corresponding region;

[0064] Figure 8 is a basic structure diagram of the radiation dosimeter provided in Example 5, wherein the arrow in Figure 8 represents the light path of the light signal;

[0065] Figure 9 is a basic structure diagram of the radiation dosimeter provided in Example 6;

[0066] Figure 10 is a structure diagram of the water tank used in the radiation dosimeter of Example 6;

[0067] Figure 11 is a schematic diagram of the first interface and the second interface positions involved in Example 6, for the convenience of comparison, the dashed line connecting the two position diagrams in the figure is the middle line of the radiation coverage, so as to clearly show the relative positions of the first interface and the second interface with reference to the middle line;

[0068] Figure 12 is a structure diagram of the water tank used in the radiation dosimeter of Example 7;

[0069] Figure 13 is a structure diagram of the water tank used in the radiation dosimeter of Example 8;

[0070] Figure 14 is a structure diagram of the water tank used in the radiation dosimeter of Example 9;

[0071] Figure 15 is a basic structure diagram of the radiation dosimeter provided in Example 10;

[0072] Figure 16 is a structure diagram of the positioning assembly of the radiation dosimeter provided in Example 10 and the connection relationship thereof. Embodiments of the present application

[0073] In order to make the person skilled in the art better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present application, not all.

[0074] Embodiment 1

[0075] 1. Basic structure of radiation dosimeter

[0076] The radiation dosimeter used in the embodiment includes a water tank 2, a light source 1, a lens group, an image acquisition module 4, a rotating platform 5 and a computer 6. The water tank 2 is a square cuboid made of quartz glass, and is provided with a square inner cavity with an open end for containing light guide fluid, which can be water or aqueous solution. After the light guide fluid is injected into the square inner cavity, a detection area is formed. The light source 1 is a laser light source capable of emitting laser light. The lens group includes a concave lens 3-3 and a first convex lens 3-1 and a second convex lens 3-2. The concave lens 3-3 is used to diffuse the light signal emitted from the light source 1 into a large-area light signal. The first lens and the second lens are convex lenses with the same shape and material. The first convex lens 3-1 is used to convert the large-area light signal passing through it into a parallel light signal, and the second convex lens 3-2 is used to converge the parallel light signal passing through the water tank 2. In this embodiment, the image acquisition module 4 is a CMOS camera. The computer 6 is provided with an image processing module, which has a three-dimensional image reconstruction function for three-dimensional reconstruction based on the two-dimensional image of the dose distribution.

[0077] The radiation dosimeter provided by the embodiment is assembled in the following manner: the radiotherapy system, the light source 1, the CMOS camera, the rotating platform 5 and the computer 6 are respectively electrically connected, so that the computer 6 can control the opening and closing of the light source 1, can receive the rotating speed of the rotating platform 5, and can receive the light intensity distribution two-dimensional image collected by the CMOS camera; the light source 1, the concave lens 3-3, the first convex lens 3-1, the second convex lens 3-2 and the CMOS camera are sequentially arranged in order, the first convex lens 3-1 and the second convex lens 3-2 are arranged opposite to each other to make the principal axes of the two coincide, the center of the light source 1, the center of the concave lens 3-3, the center of the first convex lens 3-1, the center of the second convex lens 3-2 and the lens center of the CMOS camera are all located on the principal axis of the first convex lens 3-1 and the second convex lens 3-2, and a spacing position is reserved between the first convex lens 3-1 and the second convex lens 3-2; then the water tank 2 is arranged at the spacing position between the first convex lens 3-1 and the second convex lens 3-2, pure water (pH=7) is injected into the square open cavity of the water tank 2 as a light guide fluid, and the area occupied by the light guide fluid is the detection area; the rotating platform 5 is configured to enable the light source 1, the CMOS camera and the water tank 2 to jointly perform a corner motion, and the three remain relatively static with each other in the process of performing the corner motion. According to the above assembly method, as shown in FIG. 1, the propagation path of the light signal emitted by the light source 1 is as follows: the light source 1 emits a light signal, the light signal first reaches the concave lens 3-3, the concave lens 3-3 diffuses the light signal in a large area, the diffused light signal then reaches the first convex lens 3-1, the first convex lens 3-1 converts the large-area light signal into parallel light, the parallel light is incident on the detection area, the parallel light is emitted from the detection area after passing through the detection area, and then reaches the second convex lens 3-2, and the second convex lens 3-2 converges the parallel light.

[0078] The three-dimensional radiation dose detection is performed by using the above radiation dosimeter, and the specific method is as follows:

[0079] S1. The computer 6 controls the light source 1 to be turned off, the computer 6 receives a radiation beam current trigger signal, the computer 6 controls the CMOS camera to collect the light intensity distribution two-dimensional image of the light signal emitted from the detection area, and the light intensity distribution two-dimensional image thus collected is used as a background image, and the background image is transmitted and stored in the computer 6;

[0080] S2. The radiotherapy system emits a radiation beam pulse to the detection area in the direction directly above the detection area, the radiation pulse ionizes the light guide fluid in the detection area and makes it produce hydrated electrons, and the hydrated electrons are used as ionization products;

[0081] S3. When the computer 6 receives the radiation beam trigger signal, the control light source 1 is turned on to emit light signals, which enter the detection area after being regulated by the concave lens 3-3 and the first convex lens 3-1. At this time, the light signals are absorbed by the ionized products in the light guide fluid in the detection area. Part of the light signals entering the detection area is absorbed by the ionized products, and the other part is not absorbed by the ionized products and can be emitted from the detection area. The latter reaches the second convex lens 3-2 after being emitted from the detection area, and then reaches the CMOS camera after being converged by the second convex lens 3-2. The CMOS camera collects the light signals emitted from the detection area to form a light intensity distribution two-dimensional image, and transmits the obtained light intensity distribution two-dimensional image to the computer 6.

[0082] S4. The computer 6 subtracts the light intensity distribution two-dimensional image from the above-mentioned background image to obtain a light intensity distribution two-dimensional image, and converts the light intensity distribution two-dimensional image into a dose distribution two-dimensional image based on the mapping relationship between light intensity and radiation dose.

[0083] S5. The computer 6 controls the rotation platform 5 to rotate 1°.

[0084] S6. Then repeat steps S1-S5 until the rotation angle of the rotation platform 5 accumulates to 360°.

[0085] S7. The computer 6 uses the image processing module to perform three-dimensional reconstruction on the dose distribution two-dimensional images at each angle, thereby characterizing the three-dimensional distribution of the radiation dose absorbed by the detection area.

[0086] 2. Design and construction of the experimental group

[0087] To explore the influence of the optical path length of the light signal in the detection area on the detection result, based on the basic structure of the radiation dosimeter provided in the embodiment, the optical path length of the light signal passing through the detection area is changed by setting a mirror, and the optical path length of the light signal passing through the detection area is taken as a variable. The experimental groups provided in the embodiment are numbered as experimental group 1, experimental group 2, experimental group 3, experimental group 4, and experimental group 5. The numbering and specific variable setting of each experimental group are shown in Table 1. Except for the variables shown in Table 1, the other components of the radiation dosimeter used in each experimental group and the connection mode and parameter setting thereof are strictly kept consistent. The light guide fluid used in the experimental groups shown in Table 1 is pure water with pH = 7, and nitrogen is passed into the light guide fluid to reduce the oxygen concentration of the light guide fluid to 1.7 mg / L. The light source 1 used is a laser light source with an emission wavelength of 660 nm, and the water tank 2 used is provided with a square open cavity with a size of 5 cm × 5 cm × 5 cm. The calculation method of the optical path length OPL involved in Table 1 is OPL = n × S, wherein n is the refractive index of water, n = 1.333, and S is the geometric length of the light signal passing through the detection area.

[0088] Table 1. Experimental group setting with optical path length as a variable

[0089]

[0090] Each experimental group shown in Table 1 is subjected to three-dimensional radiation dose testing using the respective radiation dosimeter according to the three-dimensional radiation dose testing method provided in the embodiment. The radiation pulse dose emitted to the detection area by each group during testing is controlled to be the same, i.e., 5 Gy.

[0091] 3. Test items and test methods

[0092] Test items: signal-to-noise ratio of radiation dose testing and lifetime of hydrated electrons.

[0093] Test method: according to the above radiation dose testing method, the radiation dosimeter is operated to perform radiation dose testing. During the radiation dose testing, the radiotherapy system emits a radiation beam pulse to the detection area in the direction directly above the detection area. The water in the detection area is ionized and generates ionized products such as hydrated electrons by the ionization of the radiation pulse. The signal-to-noise ratio and the lifetime of the water and electrons can be calculated by the degree and speed of the weakening of the laser light intensity detected by the detector.

[0094] The calculation formula of the signal-to-noise ratio is:

[0095]

[0096] A signaland A noise is the root mean square signal and noise, which is calculated as:

[0097]

[0098]

[0099] x i and y i are the ith values of the measured signal and noise, respectively, with N values measured.

[0100] The test results of the signal-to-noise ratio can be used to characterize the imaging quality of the radiation dose test, and the lower the signal-to-noise ratio, the higher the corresponding imaging quality.

[0101] The method for testing the signal-to-noise ratio is that the laser generated by the single-energy laser passes through the 5 cm wide water tank 2 and is detected by the detector, which is used to measure the change of laser intensity. The electron pulse beam generates a 5 cm × 5 cm uniform irradiation field in the water tank 2. The length of the optical path can be adjusted by the total reflection mirror 7, as shown in FIG. 2, two total reflection mirrors 7 are respectively installed on both sides of the water tank 2, and the mirror surface is perpendicular to the light so as not to block the initial incident light and the final emitted light.

[0102] After the above test, the test results show that the optical path length has no obvious effect on the lifetime of hydrated electrons, and the lifetime of hydrated electrons is about 2 μs; and the signal-to-noise ratio increases with the increase of the optical path length, and when the optical path length is 33.325 cm, the signal-to-noise ratio reaches 2.

[0103] Example 2

[0104] 1. Basic structure of the radiation dosimeter

[0105] The structure of the radiation dosimeter used in this embodiment is basically the same as that of the radiation dosimeter used in experimental group 1 of example 1, the difference is that the pH value of the light guide fluid used in this embodiment is different from that of the light guide fluid used in experimental group 1 of example 1, and nitrogen gas is introduced into the light guide fluid to adjust the oxygen concentration of the light guide fluid in this embodiment, therefore, the assembly of the radiation dosimeter and the preparation before the test are carried out according to the content recorded in experimental group 1 of example 1, and the water solution meeting the requirements of each experimental group is injected into the water tank 2 of the radiation dosimeter as the light guide fluid according to the variable setting mode of the experimental group.

[0106] 2. Design and construction of experimental groups

[0107] The experimental group 1 of the embodiment 1 is taken as the reference, the pH value of the light guide fluid in the radiation dosimeter and the oxygen concentration in the light guide fluid are taken as the variable to set the experimental groups of the embodiment, the experimental groups of the embodiment are numbered as the experimental group 6, the experimental group 7, the experimental group 8 and the experimental group 9 respectively, different concentrations of NaOH solution are taken as the light guide fluid of each experimental group in table 2, the numbers of the experimental groups of the embodiment and the corresponding pH values of the light guide fluid taken are shown in table 2, the oxygen concentration in the light guide fluid of each experimental group of the embodiment is kept at 6.5 mg / L. Except for the variables shown in table 2, the other parts of the radiation dosimeter and the connection mode and the parameter setting of each experimental group in table 2 are strictly consistent with the experimental group 1 of the embodiment 1.

[0108] Table 2. The setting of the experimental groups with the pH value of the light guide fluid as the variable

[0109]

[0110] 3. Test items and test methods

[0111] Test items: signal-to-noise ratio and hydrated electron lifetime of the radiation dose test.

[0112] Test method: the test method adopted in the embodiment is consistent with the test method of the corresponding index in the embodiment 1.

[0113] After the above test, the test results show that when the pH value is less than 11, the hydrated electron lifetime and the signal-to-noise ratio increase with the increase of the pH value; when the pH value is greater than 11, the hydrated electron lifetime and the signal-to-noise ratio remain basically unchanged. When the pH value is 11, the hydrated electron lifetime is 2 μs and the signal-to-noise ratio is 2.

[0114] Embodiment 3

[0115] 1. Basic structure of the radiation dosimeter

[0116] The structure of the radiation dosimeter adopted in the embodiment is basically consistent with that of the radiation dosimeter adopted in the experimental group 1 of the embodiment 1, the difference lies in that the light source 1 used for the incident light signal of the detection area of the radiation dosimeter in the embodiment is different from the light source 1 adopted in the experimental group 1 of the embodiment 1, the appropriate light source 1 is selected based on the corresponding light signal wavelength requirement of the radiation dosimeter provided by each experimental group of the embodiment, and the assembly of the radiation dosimeter and the preparation before the test are carried out according to the content recorded in the experimental group 1 of the embodiment 1.

[0117] 2. Design and construction of the experimental groups

[0118] The experimental groups of this embodiment are set with the laser wavelength (wavelength of the light signal incident on the detection area) emitted by the light source 1 in the radiation dose meter in the experimental group 1 of embodiment 1 as a variable. The experimental groups of this embodiment are numbered as experimental group 10 and experimental group 11, respectively. Table 3 shows that the light source 1 capable of emitting light signals of different wavelengths is used as the light source 1 of each experimental group. In addition, “experimental group 1” in Table 3 refers to the experimental group 1 set in embodiment 1. Except for the variable shown in Table 3, the other components of the radiation dose meter used in each experimental group and the connection mode and parameter setting thereof are strictly consistent with those of the experimental group 1 of embodiment 1.

[0119] Table 3. Experimental group setting with the wavelength of the light signal used for radiation dose detection as a variable

[0120]

[0121] 3. Test items and test methods

[0122] Test items: signal-to-noise ratio of radiation dose test and lifetime of hydrated electron.

[0123] Test method: The test method used in this embodiment is consistent with the test method of the corresponding index in embodiment 1.

[0124] After the above test, the test results show that the wavelength of light has no significant effect on the lifetime of hydrated electron, and the lifetime of hydrated electron is about 2 μs.

[0125] Embodiment 4

[0126] 1. Basic structure of the radiation dose meter

[0127] The structure of the radiation dose meter used in this embodiment is basically consistent with that of the radiation dose meter used in the experimental group 1 of embodiment 1, and the difference lies in that sodium sulfite solution (prepared by adding sodium sulfite to pure water) is used as the light guide fluid in this embodiment. Therefore, the assembly of the radiation dose meter and the preparation before the test are carried out according to the content recorded in the experimental group 1 of embodiment 1, and the sodium sulfite solution meeting the requirements of each experimental group is injected into the water tank 2 of the radiation dose meter as the light guide fluid according to the variable setting mode of the experimental group.

[0128] 2. Design and construction of experimental groups

[0129] (1) Effect of the type of light guide fluid on the test results

[0130] With the experimental group 1 of Example 1 as a reference, the experimental groups with the sodium sulfite content in the light guide fluid in the radiation dosimeter as a variable setting, the experimental groups set are respectively numbered as experimental group 12, experimental group 13, experimental group 14, experimental group 15, and the corresponding Table 4 uses pure water, different concentrations of sodium sulfite solution as the light guide fluid of each experimental group. The number of each experimental group in the above and the corresponding sodium sulfite content in the light guide fluid and the corresponding conversion of sodium sulfite concentration are shown in Table 4. In addition, “experimental group 1” in Table 4 refers to the experimental group 1 set in Example 1. Except for the variables shown in Table 4, the other parts of the radiation dosimeter used in each experimental group in Table 4 and their connection mode, parameter setting are strictly consistent with experimental group 1 of Example 1.

[0131] Table 4. Experimental group setting with sodium sulfite content in light guide fluid as a variable

[0132]

[0133] Test item: signal-to-noise ratio of radiation dose test and lifetime of hydrated electron.

[0134] Test method: The test method used in this embodiment is consistent with the test method of the corresponding index in Example 1.

[0135] After the above test, the test results show that in pure water, the lifetime of hydrated electron is about several μs due to the presence of oxygen. Compared with using pure water as the light guide fluid, by adding sodium sulfite to the pure water, the lifetime of hydrated electron can be extended to tens of μs, and the detection signal intensity can be enhanced, and the signal-to-noise ratio can be increased.

[0136] (2) Effect of sodium sulfite solution concentration on test results

[0137] With the experimental group 1 of Example 1 as a reference, set experimental groups with different sodium sulfite concentrations, wherein the light guide fluid is different concentrations of sodium sulfite solution, and the rest of the parts, connection mode and parameter setting are strictly consistent with experimental group 1. In the radiation dose test of each experimental group, the incident light signal remains the same, and the radiation parameter setting is pulse width 4 μs, energy 5 MeV, and current 60 mA. The absorbance of the light guide fluid after absorbing the radiation is detected, and the light intensity of the detection area is detected, and the relationship between the absorbance and the time (Fig. 3a) and the relationship between the normalized light intensity and the time (Fig. 3b) are obtained. The results show that when the concentration of sodium sulfite reaches 1.92 mmol / L or more, the absorbance changes significantly, the signal intensity increases, and the light intensity-time (time of radiation beam current incidence) curve tends to be stable. This is because sodium sulfite consumes oxygen in the light guide fluid, enhances the ionization effect under radiation, and thus enhances the absorption capacity of the light signal.

[0138] (3) Correspondence between radiation dose and optical signal

[0139] The radiation dosimeter configuration of Experimental Group 1 of Example 1 was used, and a sodium sulfite solution with a concentration of 30 mmol / L was used as the light guide fluid. By changing the radiation pulse dose, the change in the optical signal in the detection area was investigated. As shown in FIG. 4, FIG. 4a shows the change in absorbance over time at different radiation doses, and FIG. 4b shows the change in normalized light intensity over time after the radiation beam is incident. It can be seen that as the pulse dose increases, the absorbance and the change in the optical signal are significantly enhanced. Further, the EBT-XD irradiation color-changing film was used to calibrate different radiation doses, and the maximum absorbance measured by the photodetector (PD) was compared. The results are shown in FIG. 5. The maximum absorbance and the radiation dose show a good linear relationship, indicating that the change in absorbance can be used to accurately detect the radiation dose.

[0140] (4) Comparison of actual measurement of radiation dose distribution

[0141] The radiation dosimeter configuration of Experimental Group 1 of Example 1 was used, and a sodium sulfite solution with a concentration of 30 mmol / L was used as the light guide fluid. A wavelength of 660 nm was selected as the signal light source for radiation dose distribution testing. The radiation parameters were set to a pulse width of 4 μs, an energy of 5 MeV, and a current of 60 mA. The exposure time of the CMOS camera was 1 μs, and the exposure started 2 μs after the beam was emitted. At the same time, the EBT-XD irradiation color-changing film was used to measure the dose distribution under the same radiation conditions as a control. In FIG. 6, FIG. 6a shows the hydrated electron image measured by the CMOS camera of the radiation dosimeter provided by Experimental Group 1 of Example 1, and FIG. 6b shows the dose distribution on the cross-section obtained after three-dimensional reconstruction of 180 two-dimensional images (one image per 1 degree) of the dose distribution taken by the CMOS camera of the radiation dosimeter provided by Experimental Group 1 of Example 1 (corresponding to the dashed box in FIG. 6a). FIG. 7a shows the dose distribution measured by the EBT-XD irradiation color-changing film, and FIG. 7b shows the contour plot of the corresponding area (corresponding to the dashed box in FIG. 7a). The results show that the dose distribution measured by the radiation dosimeter provided by Experimental Group 1 of Example 1 is basically consistent with the measurement results of the EBT-XD film.

[0142] Example 5

[0143] The radiation dosimeter used in the embodiment comprises a water tank 2, a light source 1, a mirror 8, an image acquisition module 4, a rotating platform 5 and a computer 6. The water tank 2 is square in shape and made of quartz glass. The water tank 2 is provided with a square inner cavity with an open end, and the size of the square inner cavity is 10 cm x 10 cm x 10 cm, which is used to accommodate the light guide fluid. Water or aqueous solution can be selected as the light guide fluid, and the light guide fluid is injected into the square inner cavity to build a detection area. The light source 1 is an LED panel, and the LED panel is provided with LED light sources capable of emitting 650 nm light. The LED light sources are arranged in an array. In the embodiment, the image acquisition module 4 is a CMOS camera. The computer 6 is provided with an image processing module, and the image processing module has a three-dimensional image reconstruction function for three-dimensional reconstruction based on the two-dimensional image of the dose distribution.

[0144] The radiation dosimeter provided in the embodiment is assembled in the following manner: the light source 1, the CMOS camera, the rotating platform 5 and the computer 6 are respectively electrically connected, so that the computer 6 can control the opening and closing of the light source 1, can receive the control of the rotating speed of the rotating platform 5, and can receive the light intensity distribution two-dimensional image collected by the CMOS camera; the CMOS camera, the light source 1 and the mirror 8 are sequentially arranged in order, and a spacing position is reserved between the light source 1 and the mirror 8; then the water tank 2 is arranged at the spacing position between the light source 1 and the mirror 8, pure water (pH = 7) is injected into the square inner cavity of the water tank 2 as the light guide fluid, and the area occupied by the light guide fluid is the detection area; the rotating platform 5 is connected with the bottom surface of the water tank 2 to achieve the effect that the rotating platform 5 can drive the water tank 2 to make angular motion. As shown in FIG. 8, when the radiation dosimeter provided in the embodiment is assembled, the propagation path of the light signal during operation should satisfy: the light signal emitted by the LED panel of the light source 1 propagates upward to the half-transmissive and half-reflective element 9 of the light source 1, the light signal is emitted and then vertically enters the detection area through the side wall of the water tank 2, reaches the mirror 8 after passing through the detection area for the first time, is reflected by the mirror 8 and then vertically enters the detection area again through the side wall of the water tank 2, and the light signal reaches the CMOS camera and is collected by the CMOS camera after passing through the detection area again. The three-dimensional radiation dose detection is performed by using the above-mentioned radiation dosimeter, and the specific method is as follows:

[0145] S1. The computer 6 controls the light source 1 to be turned off. The computer 6 receives a radiation beam current trigger signal, and the computer 6 controls the CMOS camera to collect the light intensity distribution two-dimensional image of the light signal emitted from the detection area. The light intensity distribution two-dimensional image collected thereby is used as a background image, and the background image is transmitted and stored in the computer 6.

[0146] S2. The radiotherapy system emits a radiation beam pulse to the detection area from the position directly above the detection area. The radiation pulse ionizes the light guide fluid in the detection area and makes it produce hydrated electrons, and the hydrated electrons are used as ionization products.

[0147] S3. When the computer 6 receives the radiation beam trigger signal, the control light source 1 is turned on to emit a light signal, the light signal is regulated by the reflecting element of the light source 1 to propagate in a direction perpendicular to the side wall of the water tank 2, and then enters the detection area in the direction perpendicular to the side wall of the water tank 2. At this time, the light-guiding fluid in the detection area contains a certain amount of ionization products, and the ionization products have an absorption effect on the light signal passing through the detection area. Therefore, part of the light signal entering the detection area is absorbed by the ionization products, and the other part is not absorbed by the ionization products and can be emitted from the detection area. The latter is emitted from the detection area and reaches the reflecting mirror 8, is totally reflected by the reflecting mirror 8, and then enters the detection area in the direction perpendicular to the side wall of the water tank 2. In turn, the light signal passes through the detection area, the light source 1, and then reaches the CMOS camera. The CMOS camera collects the light signal emitted from the detection area to form a two-dimensional image of the light intensity distribution, and transmits the obtained two-dimensional image of the light intensity distribution to the computer 6.

[0148] S4. The computer 6 subtracts the two-dimensional image of the light intensity distribution from the above-mentioned background image to obtain a two-dimensional image of the light intensity distribution, and converts the two-dimensional image of the light intensity distribution into a two-dimensional image of the dose distribution based on the mapping relationship between the light intensity and the radiation dose;

[0149] S5. The computer 6 controls the rotation platform 5 to rotate 1°;

[0150] S6. Then, steps S1-S5 are repeated until the rotation angle of the rotation platform 5 accumulates to 360°.

[0151] S7. The computer 6 uses the image processing module to perform three-dimensional reconstruction from the two-dimensional images of the dose distribution at each angle, thereby characterizing the three-dimensional distribution of the radiation dose absorbed by the detection area.

[0152] Example 6

[0153] As shown in FIG. 9, the radiation dose meter used in this embodiment includes a water tank 2, a light source 1, a lens group (including a first double-telecentric lens 3-3 and a second double-telecentric lens 3-4), an image acquisition module 4 (in this embodiment, a CMOS camera), a base 7, a horizontal moving device 7-1, and a support platform 7-2.

[0154] As shown in FIG. 10, the water tank 2 in the embodiment is made of quartz glass, and is provided with an open inner cavity 2-1 of 5 cm x 5 cm x 5 cm, which is used to contain the light guide fluid and construct the detection area of the radiation dosimeter from the light guide fluid. In the embodiment, the light guide fluid used is a sodium sulfite solution, in which the concentration of sodium sulfite is 30 mmol / L. Three sidewalls of the inner cavity are conventional sidewalls with a thickness of 1 cm, and the remaining one sidewall (5 cm x 5 cm) is a thickened sidewall 2-2 with a thickness of 5 cm and made of quartz glass, and the thickened sidewall 2-2 is used as a transition zone of the water tank 2 and is arranged along the direction from the light inlet side to the light outlet side of the water tank and adjacent to the inner cavity 2-1. The material constituting the transition zone should satisfy that no ionization products are generated due to receiving the radiation beam, or even if the material constituting the transition zone generates ionization products after receiving the radiation beam, the ionization products generated by the material constituting the transition zone should have a shorter lifetime than the ionization products generated by the material constituting the detection area when receiving the same dose of radiation beam. Preferably, the material constituting the transition zone has a density close to that of water. As described above, in the embodiment, the transition zone is directly formed by the thickened wall plate of the inner cavity 2-1, and thus the material constituting the transition zone in the embodiment is quartz glass, which basically generates no ionization products after receiving the radiation beam and has a density close to that of water. The transition zone is provided to provide the detection area with a homogeneous substrate that generates no hydrated electron signal or a weaker hydrated electron signal relative to the detection area, so as to reduce the uncertain interference introduced by the movement of the detection area on the radiation dose detection and improve the reliability of the results of the radiation dose detection of the detection areas located at different positions.

[0155] The horizontal moving device 7-1 is fixedly installed on the base 7 and includes a slide, a sliding block 7-12 and a driving motor 7-13. The slide is provided with a lead screw 7-11, the sliding block 7-12 is sleeved on the lead screw 7-11 and is screwed with the lead screw 7-11, and the driving motor 7-13 is in transmission connection with the lead screw 7-11, so that the sliding block 7-12 can linearly move along the lead screw 7-11 under the driving of the driving motor 7-13. The top of the sliding block 7-12 is fixedly connected with the support platform 7-2. The light source 1, the first double-telecentric lens 3-3, the water tank 2, the second double-telecentric lens 3-4 and the camera are sequentially and fixedly installed on the support platform 7-2 along the extension direction of the slide, and the water tank 2 is arranged to satisfy that the transition zone and the inner cavity 2-1 of the water tank 2 are sequentially arranged along the direction from the light source 1 to the camera. Thus, the above components can linearly move as a whole along the slide under the driving of the sliding block 7-12.

[0156] In addition, the base 7 is further provided with horizontal adjustment screws 7-3 for adjusting the horizontal position of the water tank 2, so as to ensure that the water level inside the water tank 2 is kept horizontal. In this embodiment, three horizontal adjustment screws 7-3 are arranged on the base 7.

[0157] The two-dimensional radiation dose detection is performed by using the radiation dose meter, and the specific method is as follows:

[0158] (1) Selecting a detection interface

[0159] S1. According to the structure of the radiation dose meter provided in this embodiment, the components are connected and installed, the water tank 2 is moved to the ionizing radiation field, and the light guide fluid is injected into the inner cavity 2-1 of the water tank 2.

[0160] S2. Determine the detection interface, then set the position of the detection interface moving 0.5 mm along the positive direction of the slide of the horizontal moving device 7-1 as the first interface 11 (see the upper half of FIG. 11), and then set the position of the detection interface moving 0.5 mm along the negative direction (opposite to the above-mentioned “positive direction”) of the slide of the horizontal moving device 7-1 as the second interface 12 (see the lower half of FIG. 11). The first interface 11 and the second interface 12 are parallel, and the plane where the first interface 11 and the second interface 12 are located is perpendicular to the extension direction of the slide.

[0161] (2) Obtain the light intensity distribution image of the first interface 11

[0162] S1. Adjust the position of the water tank 2 along the slide direction by using the horizontal moving device 7-1, so as to make the inner wall surface of the thickened side wall 2-2 of the inner cavity 2-1 coincide with the first interface 11.

[0163] S2. Turn on the light source 1, and make the light source 1 emit light signals to the detection area. The light signals are converted into near parallel light by the first double telecentric lens 3-3, enter the water tank 2 from the light entrance side of the water tank 2, and then exit from the light exit side of the water tank 2 and are received by the second double telecentric lens 3-4. The light intensity distribution image formed by the light signals emitted from the detection area (without absorbed radiation dose) is collected by using the CMOS camera, and the first background signal is obtained.

[0164] S3. In the state of keeping the light source 1 open, the radiation source emits a radiation beam pulse to the detection area, the radiation pulse ionizes the light guide fluid in the detection area and makes it produce ionization products-hydrated electrons, the ionization products have absorption effect on the light signal passing through the detection area, thus part of the light signal entering the detection area is absorbed by the ionization products, and the other part is not absorbed by the ionization products and can be emitted from the detection area, the latter reaches the second double telecentric lens 3-4 after being emitted from the detection area, and then reaches the CMOS camera, the CMOS camera collects the light intensity distribution image formed by the light signal emitted from the detection area (having absorbed the radiation dose), and obtains the first radiation signal.

[0165] S4. The first radiation signal is subtracted from the first background signal (the light intensity of the corresponding position is subtracted), and the light intensity distribution image thus obtained is taken as the light intensity distribution image of the first interface 11.

[0166] (3) Obtain the light intensity distribution image of the second interface 12

[0167] S1. Adjust the position of the water tank 2 along the slide direction by using the horizontal moving device 7-1, so that the inner wall surface of the thickened side wall 2-2 of the inner cavity 2-1 coincides with the second interface 12, and the water tank 2 is translated, causing the position of the detection area to change and not coincide with the detection area in the previous step.

[0168] S2. Turn on the light source 1, and let the light source 1 incident light signal to the detection area, the light signal is converted into near parallel light by the first double telecentric lens 3-3, and enters the water tank 2 from the light entrance side of the water tank 2, and then is emitted from the light exit side of the water tank 2 and is received by the second double telecentric lens 3-4, and the light intensity distribution image formed by the light signal emitted from the detection area (without absorbing the radiation dose) is collected by the CMOS camera, and the second background signal is obtained.

[0169] S3. In the state of keeping the light source 1 open, the radiation source emits a radiation beam pulse (the dose of the two emitted radiation beam pulses is the same) to the detection area, the radiation pulse ionizes the light guide fluid in the detection area and makes it produce ionization products-hydrated electrons, the ionization products have absorption effect on the light signal passing through the detection area, thus part of the light signal entering the detection area is absorbed by the ionization products, and the other part is not absorbed by the ionization products and can be emitted from the detection area, the latter reaches the second double telecentric lens 3-4 after being emitted from the detection area, and then reaches the CMOS camera, the CMOS camera collects the light intensity distribution image formed by the light signal emitted from the detection area (having absorbed the radiation dose), and obtains the second radiation signal.

[0170] S4. The second radiation signal is subtracted from the second background signal (the light intensity of the corresponding position is subtracted), and the light intensity distribution image of the second interface 12 is obtained.

[0171] (4) Data processing

[0172] The light intensity distribution image between the first interface 11 and the second interface 12 is obtained by deducting the light intensity distribution image of the second interface 12 from the light intensity distribution image of the first interface 11. Based on the correction factor f (the correction factor f is obtained by comparing the light intensity change amount measured by the radiation dosimeter provided in the embodiment with the radiation dose measured by the standard dosimeter under the irradiation of the same standard radiation dose), the light intensity of each point in the light intensity distribution image between the first interface 11 and the second interface 12 is converted into a radiation dose value, and the conversion method is radiation dose=f x light intensity, thereby obtaining the radiation dose distribution image between the first interface 11 and the second interface 12. Since the detection interface is between the first interface 11 and the second interface 12, and the interval between the first interface 11 and the second interface 12 is very small, the radiation dose distribution image between the first interface 11 and the second interface 12 obtained by the above method can be approximated as the two-dimensional radiation dose distribution image of the detection interface.

[0173] According to actual needs, the water tank 2 of the radiation dosimeter provided in the embodiment can be moved along the slide during the test, so as to obtain the two-dimensional radiation dose distribution image of different detection interfaces in the detection area. Based on the measured two-dimensional radiation dose distribution image, the three-dimensional radiation dose distribution in the detection area can be obtained by fitting.

[0174] In the dose test method provided in the embodiment, the horizontal movement distance of the water tank (the distance between the first interface 11 and the second interface 12) represents the spatial resolution of the radiation dose in the moving direction (the longitudinal direction), so the resolution can be changed by adjusting the horizontal movement distance of the water tank; the resolution in the direction perpendicular to the moving direction is determined by the resolution of the CMOS camera, which can be between several microns and tens of microns.

[0175] Embodiment 7

[0176] The structure of the radiation dosimeter used in this embodiment is basically the same as that of the radiation dosimeter used in Embodiment 6, with the difference being that the specific structure of the water tank 2 and the type of light guide fluid contained therein are different. Specifically, as shown in FIG. 12, the water tank 2 used in this embodiment is made of quartz glass and has a 10 cm x 5 cm x 5 cm open inner cavity 2-1. The rectangular open inner cavity 2-1 is divided into two square open cavities of about 4.95 cm x 5 cm x 5 cm by a detachable transparent partition (about 0.1 cm thick). The two square open cavities are arranged in sequence along the direction from the light-in side to the light-out side of the water tank 2, with the square open cavity closer to the light-in side of the water tank 2 being the first cavity 2-11 and the square open cavity closer to the light-out side of the water tank 2 being the second cavity 2-12. Pure water is injected into the first cavity 2-11, and the pure water contained in the first cavity 2-11 constitutes the transition zone of the water tank 2. A 30 mmol / L sodium sulfite solution (light guide fluid) is injected into the second cavity 2-12, and the sodium sulfite solution contained in the second cavity 2-12 constitutes the detection region of the radiation dosimeter. For the requirements that the material constituting the transition zone must meet, refer to the description in Embodiment 6. When receiving the same dose of radiation beam, the lifetime of the ionization product (hydrated electron) produced by pure water is shorter than that of the ionization product (hydrated electron) produced by the sodium sulfite solution, so pure water is selected as the material of the transition zone of the radiation dosimeter provided in this embodiment, which meets the requirements. Except for the above differences, the components used in the radiation dosimeter provided in this embodiment and the corresponding positional relationship and connection relationship are the same as those in Embodiment 6.

[0177] The two-dimensional radiation dose detection is performed using the above-mentioned radiation dosimeter, and the specific method is as follows:

[0178] (1) Selecting the detection interface

[0179] S1. According to the structure of the radiation dosimeter provided in this embodiment, the components are connected and installed, the water tank 2 is moved to the ionizing radiation field, pure water is injected into the first cavity 2-11, and light guide fluid is injected into the second cavity 2-12.

[0180] S2. Determine the detection interface, which is the same as the determination operation of "first interface 11" and "second interface 12" in Embodiment 6.

[0181] (2) Obtain the light intensity distribution image of the first interface

[0182] S1. Adjust the position of the water tank 2 along the slide direction using the horizontal moving device 7-1, so that the side of the transparent partition of the water tank 2 facing the second cavity 2-12 coincides with the first interface.

[0183] S2. The first background signal is obtained by using the same operation as that for obtaining the "first background signal" in Example 6.

[0184] S3. The first radiation signal is obtained by using the same operation as that for obtaining the "first radiation signal" in Example 6.

[0185] S4. The first radiation signal is subtracted from the first background signal (the light intensity at the corresponding position is subtracted), and the light intensity distribution image thus obtained is taken as the light intensity distribution image of the first interface.

[0186] (3) Obtaining the light intensity distribution image of the second interface

[0187] S1. The position of the water tank 2 is adjusted along the slide direction by using the horizontal moving device 7-1, so that the side of the transparent partition of the water tank 2 facing the second cavity 2-12 coincides with the second interface. The translation of the water tank 2 results in the change of the position of the detection region, which is not coincident with the detection region in the foregoing step.

[0188] S2. The second background signal is obtained by using the same operation as that for obtaining the "second background signal" in Example 6.

[0189] S3. The second radiation signal is obtained by using the same operation as that for obtaining the "second radiation signal" in Example 6.

[0190] S4. The second radiation signal is subtracted from the second background signal (the light intensity at the corresponding position is subtracted), and the light intensity distribution image thus obtained is taken as the light intensity distribution image of the second interface.

[0191] (4) Data processing

[0192] The light intensity distribution image between the first interface and the second interface is obtained by subtracting the light intensity distribution image of the second interface from the light intensity distribution image of the first interface. Based on the correction coefficient f, the light intensity at each point in the light intensity distribution image between the first interface and the second interface is converted into a radiation dose value, and the conversion method is radiation dose=f x light intensity. Thus, the radiation dose distribution image between the first interface and the second interface is obtained. Since the detection interface is between the first interface and the second interface, and the interval between the first interface and the second interface is very small, the radiation dose distribution image between the first interface and the second interface obtained by the above method can be approximated as the two-dimensional radiation dose distribution image of the detection interface.

[0193] Example 8

[0194] The structural components of the radiation dosimeter used in this embodiment are basically the same as those of the radiation dosimeter used in Embodiment 6, the difference lies in the specific structure of the water tank 2 and the type of light guide fluid contained therein, specifically: as shown in FIG. 13, the water tank 2 used in this embodiment is provided with an open inner cavity 2-1, which is a 5 cm × 5 cm × 0.1 cm groove-shaped cavity, one pair of the opposite side walls (5 cm × 5 cm) of the groove-shaped cavity are thickened side walls 2-2, the thickness of the thickened side walls 2-2 is 5 cm, and the remaining one pair of opposite side walls are conventional side walls, the thickness of the conventional side walls is 1 cm; by setting the above-mentioned thickened side walls 2-2, a transition zone is formed adjacent to each side of the groove-shaped inner wall, the material of the water tank 2 used in this embodiment is the same as that of the water tank 2 of Embodiment 6, therefore the material of the above-mentioned transition zone included in the water tank 2 used in this embodiment is also quartz glass; a sodium sulfite solution (light guide fluid) with a concentration of 30 mmol / L is injected into the groove-shaped inner cavity 2-1, and the sodium sulfite solution contained in the groove-shaped cavity is used to construct the detection area of the radiation dosimeter. Based on this, in this embodiment, the material of the transition zone also meets the relevant requirements for the selection of the material of the transition zone in Embodiment 6. In addition to the above-mentioned differences, the components used in the radiation dosimeter provided in this embodiment and the corresponding positional relationship, connection relationship are the same as those of Embodiment 6.

[0195] The two-dimensional radiation dose detection is carried out by using the above-mentioned radiation dosimeter, and the specific method is as follows:

[0196] (1) Selecting the detection interface

[0197] S1. According to the structure of the radiation dosimeter provided in this embodiment, the components are connected and installed, the water tank 2 is moved to the ionizing radiation field, and the light guide fluid is injected into the groove-shaped cavity of the water tank 2.

[0198] S2. Determine the detection interface, adjust the position of the water tank 2 along the slide direction of the horizontal moving device 7-1, let the above-mentioned test interface be located in the middle of one pair of thickened side walls 2-2 of the groove-shaped inner cavity 2-1, and the test interface is parallel to the inner groove surface of the thickened side wall 2-2, and the plane where the test interface and the inner groove surface of the thickened side wall 2-2 are located is perpendicular to the slide direction.

[0199] (2) Obtain the light intensity distribution image of the detection area

[0200] S1. Turn on the light source 1, and let the light source 1 emit a light signal (the light signal involved in the following process is the same light signal) to the detection area. The light signal is converted into a near parallel light by the first double-telecentric lens 3-3, enters the water tank 2 from the light-in side of the water tank 2, and then exits from the light-out side of the water tank 2 and is received by the second double-telecentric lens 3-4. The CMOS camera collects the light intensity distribution image formed by the light signal emitted from the detection area (without absorbed radiation dose), and obtains a background signal.

[0201] S2. In the state of keeping the light source 1 turned on, make the radiation source emit a radiation beam pulse to the detection area. The radiation pulse ionizes the light guide fluid in the detection area and makes it produce ionized products-hydration electrons. The ionized products have an absorption effect on the light signal passing through the detection area. Thus, part of the light signal entering the detection area is absorbed by the ionized products, and the other part is not absorbed by the ionized products and can exit from the detection area. The latter exits from the detection area and reaches the second double-telecentric lens 3-4 and then the CMOS camera. The CMOS camera collects the light intensity distribution image formed by the light signal emitted from the detection area (with absorbed radiation dose), and obtains a radiation signal.

[0202] S3. Subtract the radiation signal from the background signal (subtract the light intensity at the corresponding position), and thus obtain the light intensity distribution image in the detection area.

[0203] (3) Data processing

[0204] Based on the correction coefficient f, the light intensity of each point in the light intensity distribution image of the detection area is converted into a radiation dose value in the form of radiation dose=f x light intensity, and thus a radiation dose distribution image of the detection area is obtained. Since the detection interface is in the middle of the detection area (in the middle of a pair of thickened side walls 2-2), and the interval between the pair of thickened side walls 2-2 is very small, the radiation dose distribution image obtained by the above method can be approximated as a two-dimensional radiation dose distribution image of the detection interface.

[0205] According to actual needs, the water tank 2 of the radiation dose meter provided in the embodiment can be moved along the slide during the test, so as to obtain the two-dimensional radiation dose distribution images of different detection interfaces in the detection area. Based on the measured two-dimensional radiation dose distribution images, fitting can be performed to obtain the three-dimensional radiation dose distribution of the detection area.

[0206] In the dose test method provided in the embodiment, the longitudinal (perpendicular to the thickened side wall 2-2) spatial resolution of the radiation dose is determined by the interval distance of the pair of thickened side walls 2-2 in the inner cavity 2-1 of the water tank 2.

[0207] Embodiment 9

[0208] The radiation dosimeter used in this embodiment has a structural composition that is basically the same as that used in Embodiment 6. The difference lies in the specific structure of the water tank 2 and the type of light-guiding fluid contained therein. Specifically, the water tank 2 used in this embodiment has a rectangular open inner cavity 2-1. A detachable transparent partition with a thickness of 0.1 cm divides the rectangular open inner cavity 2-1 into a first cavity 2-11, a second cavity 2-12, and a third cavity 2-13 arranged sequentially along the direction from the light-incident side to the light-exit side of the water tank 2. The first cavity 2-11 and the third cavity 2-13 are square open mouths with dimensions of 5 cm × 5 cm × 5 cm, while the second cavity 2-12 is 5 cm × 5 cm × 0.1 cm. A groove-shaped open cavity body of cm is constructed; pure water is injected into the first cavity 2-11 and the third cavity 2-13 to form the transition zone of the water tank 2; a sodium sulfite solution (light-guiding fluid) with a concentration of 30 mmol / L is injected into the second cavity 2-12 to form the detection area of ​​the radiation dosimeter. Based on this, in this embodiment, the material used to construct the transition zone also meets the relevant requirements for material selection in Embodiment 6. Apart from the above differences, the components used in the radiation dosimeter provided in this embodiment, as well as their corresponding positional and connection relationships, are consistent with those in Embodiment 6.

[0209] The specific method for two-dimensional radiation dose detection using the aforementioned radiation dosimeter is as follows:

[0210] (1) Select the detection interface

[0211] S1. Connect and install the components according to the structure of the radiation dosimeter provided in this embodiment, move the water tank 2 to the ionizing radiation field, inject pure water into the first cavity 2-11 and the third cavity 2-13 of the water tank 2, and inject light-guiding fluid into the second cavity 2-12;

[0212] S2. Determine the test interface, adjust the position of the water tank 2 along the extension direction of the slide of the horizontal moving device 7-1, so that the test interface is located between a pair of transparent partitions that constitute the side wall of the second cavity 2-12, and the test interface is parallel to the transparent partitions, and the plane where the test interface and the transparent partitions are located is perpendicular to the extension direction of the slide.

[0213] (2) Obtain the light intensity distribution image of the detection area.

[0214] S1. Obtain the background signal by performing the same operation as in Example 8 for obtaining the "background signal";

[0215] S2. Obtain the radiation signal by performing the same operation as in Example 8 for obtaining the "radiation signal".

[0216] S3. Subtract the radiation signal from the background signal (subtract the light intensity of the corresponding position), thereby obtaining the light intensity distribution image in the detection area.

[0217] (3) Data processing

[0218] Based on the correction coefficient f, the light intensity of each point in the light intensity distribution image of the detection area is converted into a radiation dose value, and the conversion method is radiation dose=f x light intensity, thereby obtaining the radiation dose distribution image of the detection area. Since the detection interface is in the middle of the detection area (the middle of a pair of transparent partitions), and the spacing between the pair of transparent partitions is very small, the radiation dose distribution image obtained by the above method can be approximated as a two-dimensional radiation dose distribution image of the detection interface.

[0219] According to actual needs, the water tank 2 of the radiation dosimeter provided in the embodiment can be moved along the slide during the test, so as to obtain the two-dimensional radiation dose distribution images of different detection interfaces in the detection area. Based on the measured two-dimensional radiation dose distribution images, fitting can be performed to obtain the three-dimensional radiation dose distribution of the detection area.

[0220] In the dose test method provided in the embodiment, the longitudinal (perpendicular to the transparent partition) spatial resolution of the radiation dose is determined by the spacing distance of the pair of transparent partitions in the inner cavity 2-1 of the water tank 2.

[0221] Embodiment 10

[0222] The radiation dosimeter used in the embodiment includes a base 7, a water tank 2, a light source 1 (which can emit laser with a wavelength of 660 nm), an X-axis moving system 7-3, a Y-axis moving system 7-4, a Z-axis moving system 2-3, an optical fiber, a positioning assembly 13, a filter 14, a detector 15, a signal processing unit 16, and a computer 6.

[0223] The X-axis moving system 7-3 and the Y-axis moving system 7-4 jointly constitute a horizontal moving system of the radiation dosimeter provided in the embodiment. The horizontal moving device is installed on the base 7. The X-axis moving system 7-3 comprises a first screw rod extending along the X direction, a first sliding block (containing a first nut, which is screwed with the first screw rod), and a first motor in transmission connection with the first nut. The Y-axis moving system 7-4 comprises a second screw rod extending along the Y direction, a second sliding block (containing a second nut, which is screwed with the second screw rod), and a second motor in transmission connection with the second nut. The water tank 2 is installed on the horizontal moving system and connected with the first sliding block and the second sliding block, so that the water tank 2 can be linearly moved along the X direction or the Y direction under the driving of the first motor and the second motor. The water tank 2 adopted in the embodiment is a cube made of quartz glass. The water tank 2 is provided with a square open cavity with a size of 5 cm × 5 cm × 5 cm, which is used to accommodate a light-guiding fluid. In the embodiment, the light-guiding fluid adopted is a sodium sulfite solution, in which the concentration of sodium sulfite is 30 mmol / L. The Z-axis moving system 7-5 is arranged in the water tank 2. The Z-axis moving system 7-5 comprises a third screw rod extending along the Z direction, a carrier (containing a third nut, which is screwed with the third screw rod), and a third motor in transmission connection with the third screw rod. Thus, the carrier can be linearly moved along the Z direction under the driving of the third motor. The X direction, the Y direction, and the Z direction are perpendicular to each other. Thus, the carrier can be flexibly moved in a three-dimensional space by means of the X-axis moving system 7-3, the Y-axis moving system 7-4, and the Z-axis moving system 7-5. Specifically, in the X direction, the carrier can be linearly moved along the first screw rod with the water tank 2; in the Y direction, the carrier can be linearly moved along the second screw rod with the water tank 2; and in the Z direction, the carrier can be linearly moved along the third screw rod with the carrier. In addition, the base 7 is further provided with horizontal adjustment screws 7-3 for adjusting the horizontal position of the water tank 2, so as to ensure that the water level inside the water tank 2 remains horizontal. In the embodiment, there are four horizontal adjustment screws 7-3 arranged on the base 7.

[0224] The positioning assembly 13 is used to realize the assembly of the optical fiber and the carrier. The positioning assembly 13 comprises an optical fiber clamp 13-1 and a plastic sleeve 13-2. The optical fiber clamp 13-1 comprises two optical fiber fixing portions 13-3 and a mounting hole 13-4. The two optical fiber fixing portions 13-3 are oppositely and spacedly arranged. The mounting hole 13-4 is arranged at the bottom of the optical fiber clamp 13-1 and is used to realize the positioning and mounting of the positioning assembly 13 on the carrier of the Z-axis moving system 7-5. In the embodiment, the material of the positioning assembly 13 is plastic. Thus, the density of the positioning assembly 13 is close to the density of water, which can reduce the influence of the positioning assembly 13 on the radiation field.

[0225] The optical fiber includes the incident optical fiber 101 and the exit optical fiber 102, and the plurality of incident optical fibers 101 and the plurality of exit optical fibers 102 are connected through the coupler 13-5 respectively, so as to facilitate adjustment of the length of the optical fiber and disassembly and replacement of the optical fiber. The light exit end of the incident optical fiber 101 and the light entrance end of the exit optical fiber 102 pass through an optical fiber fixing part 13-3 respectively, so that the light exit end of the incident optical fiber 101 and the light entrance end of the exit optical fiber 102 are arranged opposite and spaced apart by the optical fiber fixing part 13-3, and then the incident optical fiber 101 and the exit optical fiber 102 are fixed by the plastic sleeve 13-2 respectively. The light entrance end of the incident optical fiber 101 is connected to the laser light source 1, and the light exit end of the exit optical fiber 102 is connected to the detector 15.

[0226] In the radiation dosimeter provided in the embodiment, the detector 15 is used to detect the light intensity of the light signal and convert the light intensity signal into an electric signal, the electric signal from the detector 15 is transmitted to the signal processing unit, and the signal processing unit calculates the radiation dose value at the position of the detector 15 by processing the electric signal. In addition, the radiation dosimeter provided in the embodiment also includes a filter 14 for filtering Cerenkov light. After the light signal enters the exit optical fiber 102, it passes through the filter 14 before reaching the detector 15. Under the action of the filter 14, Cerenkov light can be filtered out, and the interference of Cerenkov light on the test result is excluded.

[0227] After the light signal enters the exit optical fiber 102, it passes through the filter 14 before reaching the detector 15. Under the action of the filter 14, Cerenkov light can be filtered out, and the interference of Cerenkov light on the test result is excluded.

[0228] The zero-dimensional radiation dose detection is performed by using the above-mentioned radiation dosimeter, and the specific method is as follows:

[0229] S1. According to the structure of the radiation dosimeter provided in the embodiment, the components are connected and installed, the light exit end of the incident optical fiber 101 and the light entrance end of the exit optical fiber 102 are positioned and installed on the sample holder in the water tank 2 through the positioning assembly 13, the interval region of the light exit end of the incident optical fiber 101 and the light entrance end of the exit optical fiber 102 is moved to the test position by adjusting the X-axis moving system 7-3, the Y-axis moving system 7-4 and the Z-axis moving system 7-5, and then the light guide fluid is injected into the water tank 2. In the embodiment, the light guide fluid used is a sodium sulfite solution, and the concentration of sodium sulfite is 30 mmol / L;

[0230] S2. Turn on the laser light source 1, the light signal emitted by the laser light source 1 is output from the incident optical fiber 101 in turn, reaches the test position (the interval region between the light output end of the incident optical fiber 101 and the light input end of the outgoing optical fiber 102), is input into the outgoing optical fiber 102, passes through the filter 14 to reach the detector 15 and is received by the detector 15, the detector 15 converts the measured light signal light intensity (background signal) into an electrical signal and then transmits the electrical signal to the signal processing unit, at this time, the light guide fluid has not absorbed the radiation dose;

[0231] S3. In the state of keeping the light source 1 turned on, make the radiation source emit a radiation beam pulse to the detection area, so that the light guide fluid is ionized, thereby the ionization product (hydrated electron) generated at the test position absorbs the light signal at the position, and the light intensity of the light signal not absorbed is output to the detector 15 through the output optical fiber, the detector 15 converts the measured light signal light intensity (radiation signal) into an electrical signal and then transmits the electrical signal to the signal processing unit, at this time, the light guide fluid has absorbed the radiation dose;

[0232] S4. Based on the correction coefficient f, the signal processing unit converts the light intensity change amount of the test position into a radiation dose value, the conversion mode is radiation dose=f x light intensity change amount, thereby obtaining the radiation dose of the test position.

[0233] According to actual conditions, in the test process, the detector 15 of the radiation dose meter provided in the embodiment can be moved along the X direction, the Y direction and the Z direction by means of the X-axis moving system 7-3, the Y-axis moving system 7-4 and the Z-axis moving system 7-5, so as to realize radiation dose test at different test positions, and through computer 6 fitting, the two-dimensional distribution and the three-dimensional distribution of the radiation dose of different interfaces in the detection area are obtained.

[0234] In the dose test method provided in the embodiment, the spatial resolution of the radiation dose is determined by the interval distance between the light output end of the incident optical fiber 101 and the light input end of the outgoing optical fiber 102.

[0235] The above embodiments are only used to illustrate the technical solutions of the present application and not to limit the protection scope of the present application, although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents, but these modifications or replacements are within the protection scope of the present application.

Claims

1. A method for detecting a three-dimensional radiation dose based on water ionization, characterized by, The method comprises the following steps: constructing a detection region by using a light-guiding fluid, radiating a radiation beam to the detection region so as to ionize the light-guiding fluid and generate ionized products, irradiating a light signal to the detection region, at least a part of the light signal being absorbed by the ionized products in the detection region, the unabsorbed light signal being emitted from the detection region, collecting the light signal emitted from the detection region to form a light intensity distribution two-dimensional image, converting the light intensity distribution two-dimensional image into a dose distribution two-dimensional image based on a mapping relationship between light intensity and radiation dose, and reconstructing a three-dimensional image by using the dose distribution two-dimensional image, so as to obtain a three-dimensional distribution of the radiation dose absorbed by the detection region according to the three-dimensional image; The light-guiding fluid is pure water or an aqueous solution.

2. The method for detecting three-dimensional radiation dose based on water ionization according to claim 1, wherein: The light path length of the light signal in the detection region is 3 cm to 2 m.

3. The method for detecting three-dimensional radiation dose based on water ionization according to claim 1, wherein: The ionized products include at least one of hydrogen ions, hydroxyl ions, hydrated hydrogen ions, hydrated hydroxyl ions, ionized water molecules, secondary excited electrons, hydrated electrons, hydrogen radicals, hydroxyl radicals, excited state water molecules, hydrogen gas and hydrogen peroxide.

4. The method for detecting three-dimensional radiation dose based on water ionization according to claim 3, characterized in that: The ionized products include hydrated electrons.

5. The method for detecting three-dimensional radiation dose based on water ionization according to claim 4, characterized in that: The wavelength range of the light signal is 100 nm to 2 μm.

6. The method for detecting three-dimensional radiation dose based on water ionization according to claim 5, wherein: The wavelength range of the light signal is 400 nm to 1000 nm.

7. The method for detecting three-dimensional radiation dose based on water ionization according to claim 4, wherein: The pH of the light-guiding fluid is 5 to 12.

8. The method for detecting three-dimensional radiation dose based on water ionization according to claim 7, wherein: The pH of the light-guiding fluid is 6 to 8.

5.

9. The method for detecting three-dimensional radiation dose based on water ionization according to claim 4, wherein: The light-guiding fluid contains sodium sulfite.

10. The method of claim 1, wherein the method is based on water ionization. The light intensity distribution two-dimensional images are collected from different positions, and the time difference between the triggering of the beam pulse and the collection of the light intensity distribution two-dimensional image is 10 ns to 1001 ms.

11. A radiation dose test method based on water ionization, characterized by, The method comprises the following steps: constructing a detection region by using a light-guiding fluid, the light-guiding fluid including at least one of pure water and an aqueous solution; irradiating a light signal to the detection region, and collecting the light intensity of the light signal to obtain a background signal; radiating a radiation beam to the detection region so as to ionize the light-guiding fluid and generate ionized products, and irradiating the light signal to the detection region again, collecting the light intensity of the light signal to obtain a radiation signal; taking the variation of the background signal and the radiation signal as an ionization absorption signal, and calculating the radiation dose absorbed by the detection region based on a mapping relationship between the ionization absorption signal and the radiation dose.

12. The method of claim 11, wherein the water ionization-based radiation dose test method is performed in vivo. The method comprises the following steps: determining a first detection region, irradiating a light signal to the first detection region, and collecting the light intensity of the light signal to obtain a first background signal; radiating a first radiation beam to the first detection region so as to ionize the light-guiding fluid and generate ionized products, irradiating the light signal to the first detection region again, collecting the light intensity of the light signal to obtain a first radiation signal, and taking the variation of the first background signal and the first radiation signal as a first ionization absorption signal; determining a second detection region, the second detection region being not completely overlapped with the first detection region, irradiating a light signal to the second detection region, and collecting the light intensity of the light signal to obtain a second background signal; a second radiation beam is emitted to the second detection area to ionize the light guide fluid to generate ionization products, the second radiation beam has the same dose as the first radiation beam, the light signal is incident on the second detection area again, and a second radiation signal is obtained by collecting the light intensity of the light signal; a second ionization absorption signal is obtained by subtracting the second ionization absorption signal from the first ionization absorption signal, and a radiation dose absorbed by a region between the first detection area and the second detection area is calculated based on a mapping relationship between the light intensity change distribution signal and the radiation dose.

13. The method of claim 11, wherein the water ionization-based radiation dose test method is performed in vivo. The ionization products include at least one of hydrogen ions, hydroxyl ions, hydrated hydrogen ions, hydrated hydroxyl ions, ionized water molecules, secondary excited electrons, hydrated electrons, hydrogen radicals, hydroxyl radicals, excited state water molecules, hydrogen gas, and hydrogen peroxide.

14. The method of claim 11, wherein the water ionization-based radiation dose test method is performed in vivo. The wavelength of the incident light is 400 nm to 1600 nm.

15. The method of claim 11, wherein the water ionization-based radiation dose test method is performed in vivo. The light guide fluid includes at least one of water and a sodium sulfite aqueous solution.

16. The method of claim 15, wherein the water ionization-based radiation dose test method is performed in vivo. The concentration of sodium sulfite in the sodium sulfite aqueous solution is 0.50 mmol / L to 30 mmol / L.

17. A radiation dosimeter, characterized by, The radiation dose meter includes: a water tank, the water tank is provided with an inner cavity for accommodating a light guide fluid, the light guide fluid is pure water or an aqueous solution, a detection area is constructed by using the light guide fluid, and the light path length in the detection area is 3 cm to 20 m; a light source, the light source is configured to emit a light signal to the detection area, the light signal is configured to be at least partially absorbed by the ionization products, and the light signal that is not absorbed is emitted from the detection area; an image acquisition module, the image acquisition module is configured to acquire a light intensity distribution two-dimensional image formed by the light signal emitted from the detection area.

18. The radiation dosimeter of claim 17, wherein: The distance between the light entrance side and the light exit side of the inner cavity of the water tank is 3 cm to 40 cm.

19. The radiation dosimeter of claim 17, wherein: The material of the water tank is at least one of quartz glass, crystal glass, or acrylic.

20. The radiation dosimeter of claim 17, wherein: The radiation dose meter further includes an image processing module, the image processing module is configured to reconstruct a three-dimensional image based on the light intensity distribution two-dimensional image.

21. The radiation dosimeter of claim 17, wherein: The radiation dose meter further includes a rotary driving device, the rotary driving device is configured to cause rotational displacement of the light source and the image acquisition module.

22. The radiation dosimeter of claim 18, wherein: The radiation dose meter further includes a slide, the slide is configured to allow the water tank to move linearly along the slide.

23. The radiation dosimeter of claim 22, wherein: The light source, the water tank, and the image acquisition system are arranged linearly along the slide.

24. The radiation dosimeter of claim 23, wherein: The inner cavity accommodates pure water and / or a sodium sulfite solution.

25. The radiation dosimeter of claim 23, wherein: The water tank further includes a transition area, the transition area is arranged adjacent to the inner cavity along the extension direction of the slide. The material constituting the transition area satisfies the following (a) or (b): a. the material constituting the transition area does not generate ionization products when receiving a radiation beam; b. The material constituting the transition region has a shorter lifetime of ionization products than the material constituting the detection region when receiving the same dose of radiation beam current.

26. The radiation dosimeter of claim 18, wherein: A double telecentric lens is arranged on the light exit side of the light source and / or the light entrance side of the image acquisition module.

27. A radiation dosimeter, characterized by, The radiation dosimeter comprises: a water tank, which is provided with an inner cavity for accommodating a light-guiding fluid, the light-guiding fluid being pure water or an aqueous solution, and the detection region is constructed by the light-guiding fluid; a light source, which is configured to emit a light signal to the detection region, the light signal being configured to be at least partially absorbed by the ionization products, and the light signal not absorbed is emitted from the detection region; a detector, which is configured to detect the light intensity of the light signal and convert the light intensity signal into an electrical signal; optical fibers, including an incident optical fiber and an exit optical fiber, the incident optical fiber being configured to guide the light signal from the light source to the test region, and the exit optical fiber being configured to guide the light signal from the test region to the detector; a signal processing unit, which is configured to calculate the radiation dose according to the electrical signal.

28. The radiation dosimeter of claim 27, wherein the radiation dosimeter is configured to determine the radiation dose by measuring the change in the electrical characteristic of the radiation dosimeter. Further comprising: an X-axis movement system, which is configured to guide the detector to move linearly along an X direction; a Y-axis movement system, which is configured to guide the detector to move linearly along a Y direction; a Z-axis movement system, which is configured to guide the detector to move linearly along a Z direction; wherein the X direction, the Y direction and the Z direction are perpendicular to each other.

29. The radiation dosimeter of claim 28, wherein: Further comprising a base, the X-axis movement system and the Y-axis movement system are arranged on the base; the water tank is mounted on the X-axis movement system and the Y-axis movement system, so that the X-axis movement system can guide the water tank to move linearly along the X direction, and the Y-axis movement system can guide the water tank to move linearly along the Y direction.

30. The radiation dosimeter of claim 28, wherein: the Z-axis movement system is arranged inside the water tank, and the Z-axis movement system comprises a carrier, which is configured to move linearly along the Z direction; the radiation dosimeter further comprises a positioning assembly, and the optical fibers are mounted on the carrier through the positioning assembly.

Images