阅读说明：本技术 一种可开展辐照实验的散裂中子源靶体 (Spallation neutron source target body capable of developing irradiation experiment ) 是由 纪全 殷雯 魏少红 张锐强 陈怀灿 李常峰 于 2020-04-08 设计创作，主要内容包括：本申请涉及一种可开展辐照实验的散裂中子源靶体,在重金属靶片(2)中穿插并排设置样品靶片(3),在样品靶片(3)中开有孔穴(31),孔穴(31)中放置样品容器(4),待进行辐照实验的样品放置于样品容器(4)的样品腔内。该散裂中子源靶体不仅具有产生中子的功能,而且所产生的大量中子对样品进行辐照。辐照到设定的剂量后,可以直接取出样品容器(4)以取出样品进行分析,不会影响靶体的正常运行和寿命。样品靶片(3)与重金属靶片(2)并排设置,中子通量高,待辐照的样品受到的辐照剂量要比中子源谱仪线上中子辐照样品的剂量高得多。可以利用该靶体进行材料的辐照效应研究。(The application relates to a spallation neutron source target body capable of developing irradiation experiments, wherein a heavy metal target sheet (2) is internally provided with sample target sheets (3) in a penetrating and side-by-side mode, a hole (31) is formed in each sample target sheet (3), a sample container (4) is placed in each hole (31), and a sample to be subjected to the irradiation experiments is placed in a sample cavity of each sample container (4). The spallation neutron source target body not only has the function of generating neutrons, but also generates a large amount of neutrons to irradiate a sample. After the irradiation reaches the set dose, the sample container (4) can be directly taken out to take out a sample for analysis, and the normal operation and the service life of the target body cannot be influenced. The sample target sheet (3) and the heavy metal target sheet (2) are arranged side by side, the neutron flux is high, and the irradiation dose of the sample to be irradiated is much higher than the dose of the neutron irradiation sample on a neutron source spectrometer line. The target body can be used for researching the irradiation effect of the material.)

1. The spallation neutron source target body capable of being used for the irradiation experiment comprises a target container (1), a heavy metal target sheet (2) and a sample target sheet (3), wherein the target container (1) comprises a groove body (11) and a cover body (12) covering the opening of the groove body (11), a target sheet installation cavity (13) is defined by the groove body (11), a gap (14) is formed in the position, right opposite to the sample target sheet (3), of the cover body (12), the heavy metal target sheet (2) and the sample target sheet (3) are arranged in the target sheet installation cavity (13) side by side, a hole (31) with an opening facing the cover body (12) is formed in the sample target sheet (3), a sample container (4) is placed in the hole (31), and a sample to be subjected to the irradiation experiment is placed in the sample container (4).

2. The target body of a spallation neutron source of claim 1, wherein the material of the target container (1) is stainless steel, the material of the heavy metal target plate (2) is tungsten, tantalum, gold, uranium or lead, and the material of the sample target plate (3) is stainless steel.

3. The target body of a spallation neutron source of claim 1, wherein the number of the heavy metal target pieces (2) and the number of the sample target pieces (3) are one or more, respectively, and the number of the holes (31) is one or more.

4. A spallation neutron source target body as claimed in claim 1, wherein the sample container (4) has a sample cavity (41) for receiving a sample to be subjected to an irradiation experiment.

5. The spallation neutron source target body of any one of claims 1 to 4, wherein the target container (1) is a single layer structure, a target window (5) is arranged at the front end of the target container (1), a cooling liquid inlet (6) and a cooling liquid outlet (7) are arranged at the rear end of the target container, and a cooling liquid flowing gap is formed between every two adjacent target plates in the target plate mounting cavity (13).

6. The target body of a spallation neutron source of claim 5, wherein at least the bottom of the target mounting cavity (13) is provided with a rib (9), the rib (9) being used to separate two adjacent target plates to form the coolant flow gap.

7. The target body of a spallation neutron source of claim 5, wherein the top and/or bottom of the target plate mounting cavity (13) is provided with a cooling fluid channel (8), and the cooling fluid channel (8) is located at the front part of the target plate mounting cavity (13), is located between two adjacent cooling fluid flow gaps, and is opposite to the top and/or bottom of the corresponding target plate.

8. The spallation neutron source target body of any of claims 1 to 4, wherein the thickness of the heavy metal target sheet (2) becomes progressively greater from the front end to the back end of the target vessel (1).

9. The spallation neutron source target body of any of claims 1 to 4, wherein the trough (11) and the cap (12) are sealed by electron beam welding and the sample target plate (3) and the cap (12) are sealed by electron beam welding.

10. The spallation neutron source target body of any one of claims 1 to 4, wherein a thermocouple (10) is disposed on the target at the front of the target mounting cavity (13), the thermocouple (10) is inserted into the heavy metal target (2) and/or the sample target (3) through the target mounting cavity (13), and the thermocouple (10) is in sealing engagement with the target mounting cavity (13).

Technical Field

The application relates to the technical field of nuclear, in particular to a spallation neutron source target body capable of developing an irradiation experiment.

Background

The spallation neutron source accelerates protons to high energy through an accelerator, and then the protons impact a heavy metal target to generate neutrons through spallation reaction. The heavy metals bombarded by high-energy protons are generally called targets, which are also the source of neutron production. The basic function of the target is to provide heavy metals for neutron production by energetic proton bombardment. The resulting neutrons are then extracted for illuminating the sample, where they undergo scattering interactions for analyzing the internal structure and microscopic properties of the sample.

According to the type of the accelerated protons of the accelerator, the accelerator is divided into a pulse type spallation neutron source (namely, the proton beam is pulse and has a certain frequency, and the generated neutrons are also pulse) and a continuous spallation neutron source. The Chinese spallation neutron source belongs to a pulse spallation neutron source, and the target body of all the current international pulse spallation neutron sources (including SNS, JPARC and ISIS in America) only has the function of generating neutrons, wherein a space for placing an irradiation experiment sample is not opened up, namely the function of irradiating the sample in the target body is not realized. Only the target body of the Switzerland SINQ continuous spallation neutron source has the function of sample irradiation, but the irradiation sample is placed in a sealed target container of the target body, if the sample is to be taken out, the target container is disassembled after the target body is used to the designed service life, the irradiation sample can be taken out, and the target body after the sample is taken out can not be used any more.

The applicant filed an invention patent application entitled "a spallation neutron source target" on 5.11.2013 (application publication No. CN 103594137 a). The spallation neutron source target comprises a target container and a target sheet, but the target sheet only has the function of generating neutrons.

Disclosure of Invention

The invention aims to solve the technical problem of providing a spallation neutron source target body capable of developing an irradiation experiment, which can place and take out an irradiated sample under the condition of not replacing the target body.

In order to solve the technical problems, the technical scheme of the invention is as follows: the utility model provides a spallation neutron source target body of experiment of can developing irradiation, including target container (1), heavy metal target piece (2) and sample target piece (3), target container (1) includes cell body (11) and lid adorns in lid (12) of the opening part of this cell body (11), target piece installation cavity (13) are defined out in cell body (11), lid (12) and sample target piece (3) just right position department open there are gap (14), heavy metal target piece (2) and sample target piece (3) set up in target piece installation cavity (13) side by side, have opening hole (31) towards lid (12) in sample target piece (3), place in hole (31) sample container (4) and wait to carry out the sample of irradiation experiment.

In a specific embodiment of the invention, the material of the heavy metal target sheet (2) is tungsten, tantalum, gold, uranium or lead, the material of the target container (1) is stainless steel, and the material of the sample target sheet (3) is stainless steel.

In the specific embodiment of the invention, the number of the heavy metal target pieces (2) and the number of the sample target pieces (3) are respectively one or more. For example, the number of the heavy metal target pieces (2) and the number of the sample target pieces (3) are two, three, four, five or more, respectively. Preferably, the number of heavy metal target pieces (2) is greater than the number of sample target pieces (3). For example, the number of the heavy metal target pieces (2) is 13, and the number of the sample target pieces (3) is 3. Preferably, the sample target plates (3) are separated by at least one heavy metal target plate (2), namely, the sample target plates (3) are not closely arranged in the target plate mounting cavity (13) side by side, and the heavy metal target plates (2) can be closely arranged in the target plate mounting cavity (13) side by side.

In a particular embodiment of the invention, the number of cavities (31) is one or more. For example, the number of holes (31) is one, two, three, four, five, six, seven, eight, nine or ten. Accordingly, the number of the sample containers (4) is one or more. For example, the number of sample containers (4) is one, two, three, four, five, six, seven, eight, nine or ten.

In a particular embodiment of the invention, the sample container (4) has a sample chamber (41) for accommodating a sample to be subjected to an irradiation experiment.

In the specific embodiment of the invention, the target container (1) is of a single-layer structure, the front end of the target container (1) is provided with a target window (5), the rear end of the target container is provided with a cooling liquid inlet (6) and a cooling liquid outlet (7), and a cooling liquid flowing gap is formed between every two adjacent target slices (the heavy metal target slice (2) and/or the sample target slice (3)) in the target slice installation cavity (13). Preferably, the cooling liquid inlet (6) and the cooling liquid outlet (7) are respectively arranged at two sides of the target plate. Preferably, at least the bottom of the target sheet mounting cavity (13) is provided with a convex rib (9), and the convex rib (9) is used for separating two adjacent target sheets to form a cooling liquid flowing gap.

In the specific embodiment of the invention, the top and/or the bottom of the target piece mounting cavity (13) is provided with a cooling liquid flow passage (8), and the cooling liquid flow passage (8) is positioned at the front part of the target piece mounting cavity (13), is positioned between two adjacent cooling liquid flow gaps and is opposite to the top and/or the bottom of the corresponding target piece.

In a specific embodiment of the present invention, the thickness of the heavy metal target piece (2) gradually becomes larger from the front end to the rear end of the target container (1). Front end in this context means the end facing the neutron source.

In the embodiment of the present invention, the groove body (11) and the lid body (12) are sealed by electron beam welding, and the sample target piece (3) and the lid body (12) are sealed by electron beam welding.

In the specific embodiment of the invention, a thermocouple (10) is arranged on the target sheet positioned in the front part of the target sheet mounting cavity (13), the thermocouple (10) penetrates through the target sheet mounting cavity (13) to be connected to the heavy metal target sheet (2) and/or the sample target sheet (3), and the thermocouple (10) is in sealing fit with the target sheet mounting cavity (13).

The invention has the advantages of

The invention discloses a spallation neutron source target capable of carrying out irradiation experiments, which is characterized in that a sample target sheet is inserted into a heavy metal target sheet on the basis of the prior invention patent application named as 'spallation neutron source target', a hole is formed in the sample target sheet, a sample container is placed in the hole, and a sample to be subjected to the irradiation experiments is placed in a sample cavity of the sample container. The spallation neutron source target body capable of developing the irradiation experiment is a component for a spallation neutron source to generate neutrons, and can be used for developing the sample irradiation damage experiment. By placing the experimental sample in a certain space (the sample cavity of the sample container) opened in the target body, the target body generates a large amount of neutrons and irradiates the sample. After the irradiation reaches the set dose, the sample container can be directly taken out to take out the sample, so that various performance analyses can be carried out on the sample after the irradiation, and the irradiation effect of the irradiation on the sample can be researched. Because the sample container can be directly taken out through the mechanical arm, the target container does not need to be damaged, and the normal operation and the service life of the target body cannot be influenced.

The general spallation neutron source target body has the function of only receiving protons to bombard and generate neutrons, the generated neutrons are led out to irradiate a sample, and the neutrons and the sample generate scattering interaction for analyzing the internal structure and the microscopic characteristics of the sample. The target body of the spallation neutron source provided by the invention not only has the basic function of generating neutrons, but also can be used for placing samples in the target body for irradiation experiments, has the irradiation function of the samples, and the irradiation dose of the samples in the target body is much higher than that of a spectrometer, so that the irradiation experiments are shortened, and the efficiency is improved.

Drawings

FIG. 1 is a perspective view of a spallation neutron source target that may be used in an irradiation experiment provided by an embodiment of the invention;

FIG. 2 shows a perspective view of a sample target;

FIG. 3 shows a top view of a sample target;

FIG. 4 shows a sample chamber and a sample chamber cover of a sample container, wherein the left panel shows a state when no sample is placed in the sample chamber and the right panel schematically shows a state when a sample is placed in the sample chamber;

FIG. 5 shows the sample container with the sample chamber cover covering the sample chamber;

fig. 6 shows a plan view and a side view of the tank body of the target container, in which the coolant flow path is shown.

Detailed Description

The present invention will be described in further detail below with reference to specific embodiments and accompanying drawings. Elements and features depicted in one drawing or one embodiment of the invention may be combined with elements and features shown in one or more other drawings or embodiments. It should be noted that components known to those of ordinary skill in the art, which are not related to the present invention, are omitted from the drawings and the description of the present invention for the sake of clarity.

FIG. 1 is a perspective view of a spallation neutron source target that may be used to perform an irradiation experiment as provided by an embodiment of the invention. As shown in fig. 1, the spallation neutron source target body comprises a target container 1 with a single-layer structure, a plurality of heavy metal target pieces 2 and a plurality of sample target pieces 3. The target container 1 comprises a groove body 11 and a cover body 12 covering the opening of the groove body, and the groove body 11 defines a target sheet installation cavity 13. The cover 12 has a slit 14 at a position facing the sample target 3. The plurality of heavy metal target pieces 2 and the plurality of sample target pieces 3 are arranged in the target piece installation cavity 13 side by side. The plurality of sample target sheets 3 have a hole 31 opened toward the cover 11, the hole 31 is provided with a sample container 4, and a sample to be subjected to an irradiation experiment is placed in the sample container 4.

The material of the heavy metal target piece 2 can be tungsten, tantalum, gold, uranium or lead, the heavy metal target piece 2 shown in fig. 1 is tungsten, the material of the target container 1 and the sample target piece 3 is stainless steel, such as 316L stainless steel, the material of the target container 1 and the material of the sample target piece 3 are both stainless steel, the sample target piece 3 and the target container 1 can be welded by electron beams, and the coolant can be prevented from leaking out of the target container 1, although the material of the sample target piece 3 can also be tungsten, so that the material also has the function of generating neutrons, the material of tungsten can not be directly welded by electron beams with the target container 1.

The number of the heavy metal target pieces 2 and the number of the sample target pieces 3 are one or more, respectively, and the number of the heavy metal target pieces 2 is preferably more than the number of the sample target pieces 3. Thirteen heavy metal target plates 2 and three sample target plates 3 are exemplarily shown in fig. 1.

The sample target 3 may be placed in front of, in the middle of, or behind the target mounting chamber 13. Generally, the neutron flux is highest in the front portion of the target body, and therefore the sample target 3 is preferably placed in front of the target mounting chamber 13.

As shown in fig. 1, the respective sample target pieces 3 are separated from each other by at least one heavy metal target piece 2, i.e., the sample target pieces 3 are not closely arranged in the target piece installation cavity 13 side by side, while the heavy metal target pieces 2 may be closely arranged in the target piece installation cavity 13 side by side. The shapes of the heavy metal target 2 and the sample target 3 are determined according to the shape of the target mounting cavity 13. In fig. 1, it is exemplarily shown that the target heavy metal target piece 2 and the sample target piece 3 are rectangular in shape.

The number of the holes 31 in the sample target 3 is one or more, and accordingly, the number of the sample containers 4 is one or more. In fig. 2 and 3, eight holes 31 are shown by way of example, and accordingly the number of sample containers 4 is eight.

As shown in fig. 4, the sample container 4 includes a sample chamber 41 for accommodating a sample to be subjected to an irradiation experiment and a sample chamber cover 42. As shown in fig. 1, the slit 14 is opened at a position where the lid 12 faces the sample target 3 in order to place and remove the sample container 4, i.e., the sample container 4 is placed in the sample target 3 through the slit 14 or removed from the sample target 3. Fig. 5 shows the state of the sample container with the sample chamber cover covering the sample chamber.

The sample to be subjected to the irradiation test may be, for example, a mechanical property sample or a morphology observation sample (e.g., a microstructure observation sample). The dimensions of these samples are generally small, for example the dimensions of the mechanical property sample may be 16mm long, 4mm wide and 0.75mm thick. Since the irradiation space of the sample chamber 41 is limited, the internal layout of the sample chamber 41 should be optimally designed to place as many samples as possible. The right hand small figure of fig. 4 schematically shows the sample chamber 41 after placement of the sample.

It should be noted that the dimensions of the target container 1, the heavy metal target flakes 2, the sample target flakes 3 and the sample container 4 are not particularly required. However, on the one hand, the design is required according to the size of the sample to be subjected to the irradiation experiment, and on the other hand, the thickness of the sample target plate 3 is required to be as small as possible so as not to affect the efficiency of neutron generation of the target body.

Referring again to fig. 1, the front end of the target container 1 is provided with a target window 5. Moreover, because the heavy metal target piece 2 of high energy proton bombardment can produce a large amount of heats, need cool off heavy metal target piece 2, consequently the rear end of target container 1 is provided with coolant liquid import 6 and coolant liquid export 7, has the coolant liquid clearance that flows between every two adjacent target pieces (heavy metal target piece 2 and/or sample target piece 3) in the target installation cavity 13. And a cooling mode of forming parallel flow of the cooling liquid between the heavy metal target plate 2 and/or the sample target plate 3 through a cooling liquid flowing gap is adopted to optimize the cooling performance. Since the first several heavy metal target pieces 2 located at the front end of the target piece mounting cavity 13 generate a large amount of heat, thermocouples 10 are provided on the several heavy metal target pieces 2, and the temperatures of the several heavy metal target pieces 2 are monitored by the thermocouples 10. The target container 1 includes a container body 11 and a lid body 12 covering an opening of the container body 1. The periphery of the groove body 11 is tightly fastened with the cover body 12 and then is welded and sealed through electron beams, and the upper end of the sample target sheet 3 is matched with the cover body 12 and then is welded through electron beams, so that the sealing of the target container 1 is ensured. The thermocouple 10 is connected to the heavy metal target 2 through the cover 12, and the thermocouple 10 is in sealing fit with the cover 12, so that the cooling liquid is prevented from leaking from the connection part of the thermocouple 10 and the cover 12.

The spallation neutron source target body provided by the embodiment of the invention is of a single-layer structure, and a cooling loop is formed in the target sheet installation cavity 13 through the cooling liquid inlet 6 and the cooling liquid outlet 7, so that the spallation neutron source target body is simple in structure and easy to process.

In order to reduce the processing difficulty of the spallation neutron source target body under the condition of meeting the engineering application, the target window 4 adopts a structure which is sunken towards the target sheet installation cavity 13 and has a cylindrical surface in the middle and spherical surfaces at two ends. It will be understood by those skilled in the art that the cylindrical and spherical surfaces referred to herein are only a portion of a complete cylindrical and spherical surface.

In order to improve the efficiency of generating neutrons, the thickness of the heavy metal target pieces 2 arranged side by side gradually increases from the front end to the rear end of the target container 1, that is, the thickness of the rear one of every two adjacent heavy metal target pieces 2 is greater than that of the front one. Front end in this context means the end facing the neutron source.

Referring to fig. 6, since the first heavy metal target pieces 2 generate a large amount of heat, the cooling liquid flow channel 8 is disposed at the top and/or bottom of the target piece installation cavity 13, and the cooling liquid flow channel 8 is located at the front end of the target piece installation cavity 13, so that the heavy metal target pieces 2 located at the front end can be in contact with more cooling liquid, and the heat dissipation capability of the heavy metal target pieces 2 is improved. Specifically, the cooling liquid flow channel 8 is disposed opposite to the corresponding heavy metal target 2, that is, the cooling liquid flow channel 8 is opposite to the top and/or the bottom of the heavy metal target 2.

The cooling liquid inlet 6 and the cooling liquid outlet 7 are respectively arranged at two sides of the heavy metal target slice 2 and/or the sample target slice 3. The cooling liquid flows from one side of the heavy metal target plate 2 and/or the sample target plate 3 to the other side of the heavy metal target plate 2 and/or the sample target plate 3 through the cooling liquid flowing gap, and cools the heavy metal target plate 2 and/or the sample target plate 3 when flowing through the cooling liquid flowing gap. Referring also to fig. 6, at least the bottom of the target plate installation cavity 13 is provided with a rib 9, and the rib 9 is used for separating two adjacent heavy metal target plates 2 and/or sample target plates 3 to form a cooling liquid flowing gap.

In the sample irradiation experiment, according to the sample container 4 designed in advance, the sample to be irradiated is marked and placed in the sample chamber 41, and then the sample chamber cover 42 is closed. The target is moved to a hot chamber where it is maintained and the sample container 4 is placed into the hot chamber. The sample container 4 is inserted by the robot into the cavity 31 of the target 3 of the target through the slit 14 and the target is then moved into the working position. The heavy metal target slice 2 receives proton irradiation to generate neutrons, and the sample in the sample target slice 3 receives the irradiation of the neutrons. After accumulating a certain dose of neutron irradiation (generally determined by calculation), the target body is moved to a hot chamber, the sample container 4 is taken out by a remote control manipulator, a new sample container 4 is replaced, the target body is continuously moved to a working position for working, and one cycle is ended. Since the sample is activated after irradiation and has a high radioactivity, the sample container 4 is cooled for a certain period of time after being removed, and after the dose is reduced to a certain level, the sample chamber cover 42 is disassembled by the manipulator, and the sample subjected to irradiation treatment is taken out from the sample chamber 41 and analyzed after irradiation.

The present invention has been described above using specific examples, which are only for the purpose of facilitating understanding of the present invention, and are not intended to limit the present invention. Numerous simple deductions, modifications or substitutions may be made by those skilled in the art in light of the teachings of the present invention. Such deductions, modifications or alternatives also fall within the scope of the claims of the present invention.