Shielding plugging piece for light beam line station wall outlet hole of synchrotron radiation device

Abstract

The utility model discloses a shielding plugging piece of a synchrotron radiation device beam line station wall outlet hole, which is characterized by comprising a square stepped hole embedded part used for being inserted into the synchrotron radiation device beam line station wall outlet hole, and a lead layer, a polyethylene layer, a lead layer and a polyethylene layer are sequentially filled in the square stepped hole embedded part along the beam direction; the lead layer comprises a plurality of lead bricks with different sizes, the polyethylene layer comprises a plurality of polyethylene bricks with different sizes, each layer of materials are arranged and stacked in a staggered joint manner, and gaps of adjacent layers of materials are not in the same straight line. According to the utility model, bremsstrahlung radiation outside the wall outlet hole at the inner side of the storage ring tunnel can be efficiently shielded, radiation in the storage ring tunnel reaching the downstream of a beam line station through the wall outlet hole is reduced, the radiation dose rate in a downstream experiment hall is further effectively reduced, and workers are prevented from being damaged by radiation.

Description

Technical Field

[0001] The utility model belongs to the technical field of synchrotron radiation, and relates to a shielding and blocking component for a wall hole of a beam line station of a synchrotron radiation device. Background Art

[0002] Synchrotron radiation facilities are large-scale facilities that generate and utilize synchrotron radiation through electron synchrotron accelerators. So far, it has developed from the first generation to the fourth generation of facilities and has become a comprehensive research platform in multiple fields. The High Energy Photon Source (HEPS) currently under construction in my country belongs to the fourth generation of synchrotron radiation facilities. The main body includes an electron linear accelerator with an energy of 0.5 GeV and a length of 74m, an enhancer with an energy of 6 GeV and a circumference of 453m, an electron storage ring with an energy of 6 GeV and a circumference of 1360.4m, and several synchrotron radiation beamlines outside the ring. HEPS can provide X-rays with an energy of up to 300 keV and has the capacity to build more than 80 high-performance beamline stations. After completion, it will become my country's first high-energy synchrotron radiation source, providing strong scientific support for industrial and scientific development.

[0003] A complete beamline station is composed of the front-end area (located in the storage ring tunnel, which is the vacuum section connecting the light source point and the downstream shed) and the downstream shed (located outside the storage ring tunnel, including the optical shed, experimental shed, etc.). In addition to synchrotron radiation, the storage ring also generates a large amount of gas bremsstrahlung and bremsstrahlung caused by beam loss during operation. The radiation passes through the beamline station wall hole (located in the short sawtooth wall of the storage ring tunnel) along the vacuum pipeline in the front-end area to reach the downstream shed of the beamline station, where it will be scattered in the shed and may also produce neutrons by photonuclear reactions with optical components along the way, becoming a direct source of radiation dose for workers during the operation and maintenance of the light source device. Therefore, it is necessary to shield stray radiation in the storage ring tunnel except for the wall hole as much as possible. The shielding of radiation in this part of the tunnel is achieved by reasonably designing and blocking the beamline wall hole on the sawtooth wall of the storage ring tunnel.

[0004] The existing hole plugging mainly adopts the following method: first, stainless steel embedded parts are installed in the wall hole, and then a whole piece of lead plate of a certain thickness is used for layered filling. This method uses lead material to shield bremsstrahlung, but ignores the neutron radiation generated by the interaction between gas bremsstrahlung and the lead plate itself. The lead plate is heavy, and it is difficult to insert the whole piece of lead plate into the wall hole without touching the vacuum pipe. It is time-consuming and has poor reusability.

[0005] Although the lead plate sealing scheme currently used can shield the bremsstrahlung radiation and limit the transmission of bremsstrahlung radiation to the downstream of the beam line, in this sealing scheme, the lead plate itself and the high-energy gas bremsstrahlung will produce neutrons, and the neutrons will also produce high-dose radiation hotspots after entering the downstream shed; since the length of the wall hole of the storage ring tunnel is 1m and the lateral size of the hole is limited, it is difficult for workers to move the entire lead plate smoothly and stuff it into the hole in a narrow space without touching the aligned vacuum pipe. The installation and adjustment are inconvenient and the shielding effect after sealing is not good; the entire lead plate is large in size and has low reusability. Utility Model Content

[0006] In view of the problems existing in the prior art, the purpose of the utility model is to provide a shielding plugging piece for the wall hole of the beam line station of a synchrotron radiation device, which is a shielding plugging piece for the wall hole of the beam line that can efficiently shield bremsstrahlung and neutron radiation, is easy to install and adjust, and has higher safety. The utility model can efficiently shield the bremsstrahlung outside the wall hole inside the storage ring tunnel, reduce the radiation in the storage ring tunnel from reaching the downstream of the beam line station through the wall hole, and further more effectively reduce the radiation dose rate in the downstream experimental hall to prevent radiation damage to the workers.

[0007] The utility model adopts the following technical solutions:

[0008] A shielding plugging part for a wall hole of a beam line station of a synchrotron radiation device, characterized in that it comprises a square stepped hole embedded part for inserting into the wall hole of the beam line station of a synchrotron radiation device, wherein the square stepped hole embedded part is filled with a lead layer, a polyethylene layer, a lead layer, and a polyethylene layer in sequence along the beam direction; the lead layer comprises a plurality of lead bricks of different sizes, and the polyethylene layer comprises a plurality of polyethylene bricks of different sizes, and each layer of material is stacked with staggered seams, and the gaps between adjacent layers of material are not on the same straight line.

[0009] Furthermore, the square stepped hole embedded part has a smaller aperture on the side close to the storage ring tunnel and a larger aperture on the side close to the beam line station.

[0010] Furthermore, the square step hole embedded part has a 400mm×400mm square hole on the side close to the storage ring tunnel and a 450mm×450mm square hole on the side close to the beamline station. The square step hole embedded part is made of 304 stainless steel with a wall thickness of 10mm.

[0011] Furthermore, the length of the wall hole of the beam line station of the synchrotron radiation device is 1m, and the square stepped hole embedded part is filled with a 25cm thick lead layer, a 25cm thick polyethylene layer, a 25cm thick lead layer, and a 25cm thick polyethylene layer in sequence along the beam direction.

[0012] Furthermore, the same material layer includes three sub-layers with a narrow strip in the middle and wide strips on both sides.

[0013] The shielding plugging parts of the wall hole of the beam line station of the synchrotron radiation device of the present application include preparing a square step hole embedded part, with a small aperture on the side close to the storage ring tunnel and a large aperture on the side close to the beam line station; using the Monte Carlo program FLUKA simulation to find out the effective combination of polyethylene and lead materials, during the plugging construction, the plugging materials are sequentially inserted into the square step hole embedded part, from the inside to the outside of the storage ring tunnel, in turn, the lead layer, polyethylene layer, lead layer, polyethylene layer; the lead and polyethylene materials are processed into lead bricks and polyethylene bricks of different small sizes, each layer of material is stacked in staggered arrangement, and the gaps of adjacent layers of material are not on the same straight line. The effective layered combination of lead bricks and polyethylene bricks in the shielding plugging parts, and the staggered arrangement of small-sized bricks when each material is stacked, these two means combined enable the shielding plugging parts to effectively block the stray radiation outside the light hole from reaching the downstream experimental hall.

[0014] The present application improves the traditional embedded part structure and designs it into a square stepped hole embedded part, which can prevent straight-through gaps from occurring at the edge of the wall hole. This design makes the shielding effect of the wall hole more complete.

[0015] The square stepped hole embedded part has a 400mm×400mm square hole on the side close to the storage ring tunnel and a 450mm×450mm square hole on the side close to the beamline station. The wall thickness is 10mm and the material is 304 stainless steel. After installation, the debris in the hole is cleaned and then wait for sealing.

[0016] The effective combination of polyethylene and lead was simulated by Monte Carlo FLUKA program. The length of the wall hole was 1m. The dose rates of the following 8 different combinations of lead and polyethylene materials were compared and analyzed. From the inner side of the storage ring tunnel to the side of the downstream hall of the beam line, they are:

[0017] Plan 1, 50 cm lead, 50 cm polyethylene;

[0018] Plan 2, 25 cm polyethylene, 50 cm lead, 25 cm polyethylene;

[0019] Plan 3, 25 cm lead, 50 cm polyethylene, 25 cm lead;

[0020] Plan 4, 35 cm lead, 50 cm polyethylene, 15 cm lead;

[0021] Plan 5, 25 cm lead, 25 cm polyethylene, 25 cm lead, 25 cm polyethylene;

[0022] Plan 6, 30 cm lead, 20 cm polyethylene, 30 cm lead, 20 cm polyethylene;

[0023] Plan 7, 20 cm lead, 30 cm polyethylene, 20 cm lead, 30 cm polyethylene;

[0024] Plan 8, 20cm lead, 20cm polyethylene, 10cm lead, 20cm lead, 20cm polyethylene, 10cm lead.

[0025] By simulating the dose rate distribution on one side of the wall hole beam line hall under different combination schemes, it can be seen that the dose rate level on one side of the hall is the lowest when using the layered blocking method of 25cm lead, 25cm polyethylene, 25cm lead, and 25cm polyethylene, which meets the radiation safety needs of the staff. Therefore, this scheme is adopted during construction.

[0026] The staggered arrangement and stacking of the small-sized bricks in each material does not leave any straight seams, thereby preventing radiation from directly passing through the wall hole to reach the downstream of the beam line station.

[0027] The utility model analyzes the effective combination of polyethylene and lead materials through simulation and comparison of the Monte Carlo program FLUKA, and adopts a blocking method of 25cm lead, 25cm polyethylene, 25cm lead, and 25cm polyethylene to maximize the function of shielding stray radiation outside the light hole and limiting its transmission to the downstream of the beam line station.

[0028] In the utility model, lead and polyethylene are processed into blocks of different sizes, which are convenient for workers to smoothly insert into holes in narrow spaces during construction, and are easy to install and adjust.

[0029] In the utility model, the shielding material layer is stacked without straight-through gaps, which further optimizes the shielding effect and prevents radiation from directly passing through the gaps into the downstream of the beam line station. The stacking structure is compact and stable and has strong reusability.

[0030] The advantages of the utility model are as follows:

[0031] The wall hole shielding plugging piece proposed by the utility model adopts the method of effectively combining two materials, polyethylene and lead, which can not only shield the bremsstrahlung radiation and limit its transmission to the downstream of the beam line station, but also shield the neutron radiation generated by the photonuclear action of high-energy gas bremsstrahlung and lead. The lead and polyethylene in this method are cut into blocks of different sizes, which are convenient for workers to smoothly insert into the holes in narrow spaces during construction, and the installation and adjustment are convenient. The lead blocks and polyethylene blocks are stacked without straight-through gaps, which further optimizes the shielding effect and prevents radiation from directly passing through the gaps into the downstream of the beam line station. The stacking structure is compact and stable, easy to disassemble and assemble, and highly reusable. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the structure of this application.

[0033] Figure 2 It is a cross-sectional view of the structure of this application.

[0034] Reference numerals: 1 - lead material layer, 2 - polyethylene material layer. DETAILED DESCRIPTION

[0035] The present invention will be described in further detail below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0036] like Figure 1 As shown, a blocking scheme for implementing the utility model is a situation where there is no vacuum pipe in the wall hole, wherein the materials from one side of the storage ring tunnel to the downstream of the beamline station are 25 cm lead, 25 cm polyethylene, 25 cm lead, and 25 cm polyethylene, respectively.

[0037] like Figure 2 The utility model shows a cross-sectional view of each layer and a detailed list of bricks of different sizes. Through the arrangement and stacking of bricks of different sizes, this method can make the hole structure compact and stable, without straight-through gaps, the construction process is simple and fast, and the safety and reusability are stronger.

[0038] Other materials or different combinations of lead and polyethylene can also be used for sealing in this application. Compared with the utility model, although it can achieve the function of shielding gas bremsstrahlung and neutron radiation, the shielding performance is far inferior to the efficient combination of 4 layers of lead and polyethylene materials, and it has high economic cost, difficult installation and adjustment, consumes more time, and has poor reusability.

[0039] The advantages of the utility model are mainly as follows: first, the use of polyethylene and lead as two materials and a four-layer effective combination can effectively shield gas bremsstrahlung and neutron radiation, limiting their transmission to the downstream of the beam line station; second, the lead and polyethylene in this method are processed into blocks of different sizes, which are convenient for workers to smoothly insert into holes in narrow spaces during construction without touching the aligned vacuum pipes, and are convenient for installation and adjustment. The construction process is simple and fast, and the time consumption is short, which can save construction period and improve construction efficiency; third, the lead blocks and polyethylene blocks are stacked without straight-through gaps, which further optimizes the shielding effect and prevents radiation from directly passing through the gaps into the downstream of the beam line station. The stacking structure is compact and stable, and has strong reusability.

[0040] Although the specific embodiments of the present invention are disclosed for the purpose of illustration, the purpose is to help understand the content of the present invention and implement it accordingly. Those skilled in the art can understand that various substitutions, changes and modifications are possible without departing from the spirit and scope of the present invention and the attached claims. Therefore, the present invention should not be limited to the content disclosed in the best embodiment, and the scope of protection claimed by the present invention shall be based on the scope defined in the claims.

Claims

1. A shielding plugging member for a wall hole of a beam line station of a synchrotron radiation device, characterized in that: It comprises a square stepped hole embedded part for inserting into the wall hole of the beam line station of a synchrotron radiation device, wherein the square stepped hole embedded part is filled with a lead layer, a polyethylene layer, a lead layer, and a polyethylene layer in sequence along the beam direction; the lead layer comprises a plurality of lead bricks of different sizes, and the polyethylene layer comprises a plurality of polyethylene bricks of different sizes, and each layer of material is stacked in a staggered arrangement, and the gaps between adjacent layers of material are not on the same straight line.

2. The shielding and plugging member for the wall hole of the beam line station of the synchrotron radiation device according to claim 1, characterized in that: The square stepped hole embedded part has a smaller aperture on the side close to the storage ring tunnel and a larger aperture on the side close to the beam line station.

3. The shielding and blocking member for the wall hole of the beam line station of the synchrotron radiation device according to claim 2, characterized in that: The square step hole embedded part has a 400mm×400mm square hole on the side close to the storage ring tunnel and a 450mm×450mm square hole on the side close to the beam line station. The square step hole embedded part is made of 304 stainless steel with a wall thickness of 10mm.

4. The shielding and blocking member for the wall hole of the beam line station of the synchrotron radiation device according to claim 1, 2 or 3, characterized in that: The length of the wall hole of the beam line station of the synchrotron radiation device is 1m, and the square stepped hole embedded part is filled with a 25cm thick lead layer, a 25cm thick polyethylene layer, a 25cm thick lead layer, and a 25cm thick polyethylene layer in sequence along the beam direction.

5. The shielding and blocking member for the wall hole of the beam line station of the synchrotron radiation device according to claim 1, 2 or 3, characterized in that: The same material layer includes three sub-layers with a narrow strip in the middle and wide strips on both sides.

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