CN110831314A - Cyclotron ionizing radiation self-shielding device of magnet yoke external isotope target system - Google Patents

Abstract

The invention relates to the technical field of cyclotrons, and discloses a cyclotron ionizing radiation self-shielding device of a magnetic yoke outer isotope target system, comprising an isotope production target chamber, an accelerator coating layer and a driving device. The accelerator coating layer is coated on the cyclotron. The side and top of the accelerator, the accelerator cladding is divided into a left shield body and a right shield body, and the driving device drives the left shield body and the right shield body to move in a straight line in the opposite or reverse direction to close or open. The isotope production target chamber close to the yoke of the cyclotron is embedded in the inner side of the left shield body and the right shield body, and the cyclotron production target is located in the isotope production target chamber, the isotope production target chamber A lead shielding layer and a boron-containing polyethylene shielding layer are arranged on the periphery, and the invention realizes effective shielding of the ionizing radiation field generated by the cyclotron, improves the safety and reliability of the medical device, and ensures the safety of the staff.

Description

A cyclotron ionizing radiation self-shielding device for a magnetic yoke external isotope target system

technical field

The invention relates to the technical field of cyclotrons, in particular to a cyclotron ionizing radiation self-shielding device used in a magnetic yoke outer isotope target system in medical isotope production equipment.

Background technique

At present, in the cyclotron for the production of medium and short-lived isotopes for medical use, the isotope production target system and the accelerator body will generate neutron and photon ionizing radiation during operation. According to the current regulations and standards in China, it is necessary to protect against ionizing radiation and reduce the dose rate limit required by the standard to ensure the safety of radioactive workers and the public. The shielding of ionizing radiation of accelerators for isotope production usually requires a large thickness of concrete for protection, and the protection measures are usually completed by building structures such as shielding walls. The large-thickness shielding wall has the disadvantages of difficult construction, large area and high cost. In order to reduce the shielding thickness of the cyclotron building for isotope production and rationally utilize the space of the accelerator room, it is urgent to design a self-shielding device of multilayer composite shielding material for ionizing radiation shielding of the accelerator.

Various isotope production targets at home and abroad are usually installed in the yoke of the accelerator, and the self-shielding of the accelerator usually does not require the design of an independent isotope target chamber. The multi-target isotope production target system requires a large installation and maintenance space, and is more suitable for installation in a workshop with a shielded structure. Therefore, a self-shielding device is designed and developed that provides an independent isotope target chamber outside the magnetic yoke, which can provide the installation of a multi-target isotope production target system to reduce the shielding requirement of the workshop.

SUMMARY OF THE INVENTION

In view of the deficiencies in the prior art, the purpose of the present invention is to provide a cyclotron ionizing radiation self-shielding device of a magnetic yoke outer isotope target system, which realizes effective shielding of the ionizing radiation field generated by the cyclotron and improves the performance of the medical device. Safety and reliability to ensure the safety of staff.

The above-mentioned technical purpose of the present invention is achieved through the following technical solutions:

A cyclotron ionizing radiation self-shielding device for an isotope target system outside a magnetic yoke, comprising an isotope production target chamber, an accelerator cladding layer and a driving device, the accelerator cladding layer is clad on the side and top of the cyclotron, and the accelerator The cladding layer is divided into a left shield body and a right shield body which are assembled. The driving device drives the left shield body and the right shield body to move in a straight line in the opposite or reverse direction to close or open the accelerator cladding layer. The shielding body and the inner side of the right shielding body are embedded with an isotope production target chamber close to the yoke of the cyclotron, and the production target of the cyclotron is located in the isotope production target chamber. The boron polyethylene shielding layer, the lead shielding layer and the boron-containing polyethylene shielding layer are all inlaid in the accelerator cladding layer.

By adopting the above technical solution, the accelerator cladding layer is divided into a left shield body and a right shield body which are assembled together. The left shield body and the right shield body can be moved in opposite or opposite directions through the driving device respectively, so as to realize the closing or opening and closing function. When the accelerator cladding layer is opened and closed, it is used to provide a maintenance and inspection space for the cyclotron, and when the accelerator cladding layer is closed, the ionizing radiation shielding of the cyclotron is realized. A lead shielding layer and a boron-containing polyethylene shielding layer are arranged outside the isotope production target chamber. The boron-containing polyethylene shielding layer moderates and absorbs the neutron ionizing radiation generated by the isotope production target, and the isotope production target is protected by the lead shielding layer. The generated photon ionizing radiation is shielded, and the space of the isotope production target chamber is rationally designed; at the same time, the boron-containing concrete of the accelerator coating layer shields the ionizing radiation caused by the stray beam loss generated inside the accelerator. The shielding device reasonably utilizes the space of the cyclotron installation hall, reduces the shielding requirements of the cyclotron installation hall, and ensures the safety of the entire system.

According to the present invention, the left shield body and the right shield body are respectively provided with accommodating cavities for accommodating the cyclotron, the upper part of the accommodating cavity is a top cover covering the top of the cyclotron, and the left shield body The inner edge of the top cover can be combined with the inner edge of the top cover of the right shield.

By adopting the above technical solution, the accelerator cladding layer adopts a non-uniform thickness mode according to the spatial distribution characteristics of the radiation field generated by the cyclotron, and reasonably optimizes the lateral and top shielding thickness to improve the space utilization rate of the accelerator cladding layer. And reduce the weight of the self-shielding device.

The present invention further provides that the inner edges of the top covers of the left shield body and the right shield body are respectively provided with mutually matched stepped surfaces, and the edge lines of the inner edges of the top cover are convex and concave.

By adopting the above technical solution, the joint part of the left shield body and the right shield body of the accelerator cladding adopts a stepped surface splicing structure, and the edge line of the inner edge of the top cover is convex and concave, which is used to prevent ionizing radiation from passing through Gap leaks.

According to the present invention, the materials of the left shield body and the right shield body of the accelerator coating layer are both steel fiber concrete containing boron, and the mass percentage of boron is 5%.

By adopting the above technical scheme, a non-standard concrete material with a boron content of 5% and steel fibers is used to make the accelerator cladding layer to achieve ionizing radiation shielding. The shielding material not only improves the shielding efficiency of the accelerator cladding layer, but also improves the accelerator cladding. Overall strength of the cladding.

According to the present invention, the material of the boron-containing polyethylene shielding layer is a boron-containing polyethylene composite material, and the mass percentage of boron is 3-5%; the material of the lead shielding layer is lead.

By adopting the above technical solution, the boron-containing polyethylene shielding layer is made of boron-containing polyethylene composite material, and the mass percentage of boron is 3-5%, the lead shielding layer is made of lead, and the boron-containing polyethylene shielding layer produces the isotope production target. The neutron ionizing radiation is moderated and absorbed, the lead shielding layer shields the photon ionizing radiation generated by the isotope production target, and the space of the isotope production target room is rationally designed.

The present invention further provides that the left shield body and the right shield body are both driven by a driving device to move linearly along a track laid on the basic ground, and the driving device includes a bottom shield mounted on the left shield body or the right shield body. The driving motor, the driving wheel group and the driven wheel group are connected in a transmission manner with the driving wheel group, and the driving motor drives the driving wheel group and the driven wheel group to roll synchronously along the track.

By adopting the above technical solution, the left shield body and the right shield body can be driven by the driving device to move in opposite or opposite directions along the track laid on the foundation ground respectively, so as to realize the function of closing or opening the accelerator cladding layer.

In the present invention, three parallel tracks are laid on the basic ground, and a set of driving wheel sets and two sets of driven wheel sets are installed on the bottom of the left shield body and the right shield body. Track rolling, two sets of driven wheel sets roll along the two tracks on the front and rear respectively, the three tracks are P43 heavy rails, the driving wheel set and the driven wheel set are load-bearing rollers, and the drive motor is a frequency conversion motor.

By adopting the above technical solution, three parallel rails are laid on the foundation ground, all of which are P43 heavy rails, the driving wheel set and the driven wheel set are load-bearing rollers, the driving motor is a variable frequency motor, and the driving wheel set is driven by a variable frequency motor The left shield body and the right shield body realize linear motion, which meets the installation, use and maintenance of the cyclotron, as well as the operation requirements of the accelerator cladding layer.

The present invention is further provided that limit buffers and limit switches corresponding to the left shield body and the right shield body are respectively provided near the ends of the two ends of the track, and the limit switches and the controller of the variable frequency motor are respectively provided. The limit switch is a photoelectric limit switch or a mechanical limit switch.

By adopting the above technical scheme, limit buffers are added at the end positions of the left shield body and the right shield body, so as to ensure that the left shield body and the right shield body run to the set position and stop safely and reliably. The left shield body and the right shield body are driven by variable frequency motors, and the transition process of buffer start and stop is set to avoid damage to the equipment caused by hard collision. Photoelectric limit switches or mechanical limit switches are set at the end positions of the left and right shields. While controlling the movement of the left and right shields, they provide a switch for the accelerator cladding for the overall system. Status information to realize the safety interlock control of the cyclotron.

According to the present invention, the buffer part of the limit buffer is made of polyurethane material, and the limit bracket of the limit buffer is welded with steel plates.

By adopting the above technical solution, the limit buffer is used to ensure that the left shield body and the right shield body can stop safely and reliably at the set position, and the transition process of buffer start and stop is set to avoid damage to the equipment caused by hard collision.

The present invention further provides that hooks are provided on the tops of the left shielding body and the right shielding body.

By adopting the above technical solution, the hook on the top of the accelerator cladding layer facilitates the transportation, installation, use and maintenance of the accelerator cladding layer.

To sum up, the beneficial technical effects of the present invention are:

The accelerator cladding layer of the present invention is divided into a left shield body and a right shield body formed by splicing. The left shield body and the right shield body can be moved toward or in opposite directions by a driving device respectively, so as to realize closing or opening and closing. function. When the accelerator cladding layer is opened and closed, it is used to provide a maintenance and inspection space for the cyclotron, and when the accelerator cladding layer is closed, the ionizing radiation shielding of the cyclotron is realized. A lead shielding layer and a boron-containing polyethylene shielding layer are arranged outside the isotope production target chamber. The boron-containing polyethylene shielding layer moderates and absorbs the neutron ionizing radiation generated by the isotope production target, and the isotope production target is protected by the lead shielding layer. The generated photon ionizing radiation is shielded, and the space of the target chamber for isotope production is rationally designed;

The accelerator cladding layer of the present invention adopts a non-uniform thickness mode according to the spatial distribution characteristics of the radiation field generated by the cyclotron, and reasonably optimizes the shielding thickness of the lateral and top layers, so as to improve the space utilization rate of the accelerator cladding layer and reduce the self-contained thickness. The weight of the shielding device; the non-standard concrete material with a boron content of 5% and steel fibers is used to make the accelerator cladding layer to achieve ionizing radiation shielding, which not only improves the shielding efficiency of the accelerator cladding layer, but also improves the accelerator cladding. The overall strength of the layer; the boron-containing polyethylene shielding layer moderates and absorbs the neutron ionizing radiation generated by the isotope production target, and the lead shielding layer shields the photon ionizing radiation generated by the isotope production target. The space of the isotope production target chamber is rationally designed, and the size of the accelerator cladding layer is optimized according to the distribution characteristics of the cyclotron radiation field, which realizes the effective shielding of the ionizing radiation field generated by the cyclotron, and improves the safety and reliability of medical devices. ensure the safety of staff;

The invention adds limit buffers at the end positions of the left shield body and the right shield body running to ensure that the left shield body and the right shield body run to the set positions and stop safely and reliably. The left shield body and the right shield body are driven by variable frequency motors, and the transition process of buffer start and stop is set to avoid damage to the equipment caused by hard collision. Photoelectric limit switches or mechanical limit switches are set at the end positions of the left and right shields. While controlling the movement of the left and right shields, they provide a switch for the accelerator cladding for the overall system. Status information to realize the safety interlock control of the cyclotron.

The invention provides a larger installation space for the isotope production target, can accommodate more target positions, adopts the composite shielding structure of the lead shielding layer and the boron-containing polyethylene shielding layer, and realizes a special large-space compact isotope production target room ; At the same time, a special ratio of boron-containing steel fiber reinforced concrete material is used as the accelerator cladding layer, which reduces the overall shielding thickness of the self-shielding device and improves the mechanical properties of the shielding structure. The space in the cyclotron hall.

Description of drawings

Fig. 1 is the overall structure schematic diagram of cyclotron ionizing radiation self-shielding device of the present invention;

FIG. 2 is a schematic structural diagram of the right shield body of the accelerator cladding layer shown in FIG. 1;

FIG. 3 is a schematic structural diagram of the left shield body of the accelerator cladding layer shown in FIG. 1;

4 is a schematic diagram of the closed state of the accelerator cladding layer of the present invention;

FIG. 5 is a horizontal cross-sectional view of the cyclotron ionizing radiation self-shielding device shown in FIG. 4 .

Reference numerals: 1. Cyclotron; 2. Lead shielding layer; 3. Boron-containing polyethylene shielding layer; 4. Accelerator cladding layer; 5. Left shielding body; 6. Right shielding body; 7. Isotope production target Room; 8. Driving wheel set; 9. Driven wheel set; 10. Limit buffer; 11. Hook; 12. Track; 13. Foundation ground; 14. Top cover; 15. Inner edge; 16. Edge line; 17. Production of targets.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings.

As shown in Figures 1 and 5, the present invention discloses a cyclotron ionizing radiation self-shielding device of a magnetic yoke outer isotope target system, including an isotope production target chamber 7, an accelerator coating layer 4 and a driving device, and the accelerator coating layer 4 is coated on the side and top of the cyclotron 1, and the accelerator coating layer 4 is divided into a left shield body 5 and a right shield body 6 which are assembled, and the driving device drives the left shield body 5 and the right shield body 6. Make a linear movement in the opposite or reverse direction to close or open and close the accelerator cladding layer 4, the inner side of the left shield body 5 and the right shield body 6 are embedded with isotope production target chambers 7 close to the yoke of the cyclotron 1, And the production target 17 of the cyclotron 1 is located in the isotope production target chamber 7, and the lead shielding layer 2 and the boron-containing polyethylene shielding layer 3 are arranged around the isotope production target chamber 7, and the lead shielding layer 2 and the boron-containing polyethylene shielding layer 3 are all arranged. Inlaid in the accelerator cladding layer 4;

As shown in FIGS. 2 and 3 , the left shield body 5 and the right shield body 6 are respectively provided with accommodating cavities for accommodating the cyclotron 1 , and the upper part of the accommodating cavity is a top cover covering the top of the cyclotron 1 14. The inner edge 15 of the top cover 14 of the left shield body 5 can be combined with the inner edge 15 of the top cover 14 of the right shield body 6; The edges 15 are respectively provided with mutually matched step surfaces, and the edge line 16 of the inner edge 15 of the top cover 14 is convex and concave; the tops of the left shield body 5 and the right shield body 6 are provided with hooks 11; the accelerator cladding layer The left shielding body 5 and the right shielding body 6 of 4 are made of boron-containing steel fiber reinforced concrete, and the mass percentage of boron is 5%; the boron-containing polyethylene shielding layer 3 is made of boron-containing polyethylene composite material, and The mass percentage of boron is 3-5%; the material of lead shielding layer 2 is lead;

As shown in Figures 4 and 5, three mutually parallel rails 12 are laid on the foundation ground 13, and the left shield body 5 and the right shield body 6 are driven by the driving device to move linearly along the three mutually parallel rails 12. The driving device It includes a drive motor installed at the bottom of the left shield body 5 or the right shield body 6, a group of driving wheel groups 8, and two groups of driven wheel groups 9. The driving motor is connected with the driving wheel group 8 in a transmission phase, and the driving motor drives the driving wheel. The group 8 and the driven wheel group 9 roll synchronously along the track 12, the driving wheel group 8 rolls along the middle track 12, the two groups of driven wheel groups 9 roll along the two tracks 12 on the front and the rear respectively, and the three tracks 12 are all P43 On the heavy rail, the driving wheel set 8 and the driven wheel set 9 are load-bearing rollers, and the driving motor is a frequency conversion motor; The limit buffer 10 and the limit switch, the limit switch is connected with the controller of the variable frequency motor, the limit switch is a photoelectric limit switch or a mechanical limit switch, the buffer part of the limit buffer 10 is made of polyurethane material, and the limit switch is made of polyurethane. The limit bracket of the position buffer 10 is welded by steel plates.

When this embodiment is used,

The left shielding body 5 and the right shielding body 6 of the accelerator cladding layer 4 are driven by the driving device to move toward or in opposite directions along the three mutually parallel rails 12 to close or open the accelerator cladding layer 4. A limit buffer 10 is added to the end position to ensure that the left shielding body 5 and the right shielding body 6 run to the set position and stop safely and reliably. The accelerator cladding layer 4 is used to provide a maintenance and inspection space for the cyclotron 1 when the accelerator cladding layer 4 is opened and closed. When the accelerator cladding layer 4 is closed, the ionizing radiation shielding of the cyclotron 1 is realized. The production target 17 of the cyclotron 1 is located in the isotope production target chamber 7 , a lead shielding layer 2 and a boron-containing polyethylene shielding layer 3 are arranged around the isotope production target chamber 7 to form a composite shielding structure, the neutron ionizing radiation generated by the production target 17 is moderated and absorbed, and the lead shielding layer 2 produces the production target 17. photon ionizing radiation shield. The joint part of the left shield body 5 and the right shield body 6 of the accelerator cladding layer 4 adopts a stepped surface splicing structure, and the edge line 16 of the inner edge 15 of the top cover 14 is convex and concave, which is used to prevent ionizing radiation from passing through Gap leaks.

The above are only the preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions under the idea of the present invention belong to the protection scope of the present invention. It should be pointed out that for those skilled in the art, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims (10)

1. The utility model provides a cyclotron ionizing radiation of outer isotope target system of yoke is from shield assembly, including isotope production target room (7), accelerator coating (4) and drive arrangement, accelerator coating (4) cladding in the side direction of cyclotron (1), top, its characterized in that, accelerator coating (4) divide into left side shield (5), right side shield (6) that the amalgamation formed, drive arrangement drive left side shield (5) and right side shield (6) do opposite directions or reverse rectilinear movement in order to close or open and shut accelerator coating (4), the medial surface of left side shield (5), right side shield (6) all inlays and is equipped with the isotope production target room (7) that is close to cyclotron (1) yoke, and production target (17) of cyclotron (1) are located isotope production target room (7), the periphery of the isotope production target chamber (7) is provided with a lead shielding layer (2) and a boron-containing polyethylene shielding layer (3), and the lead shielding layer (2) and the boron-containing polyethylene shielding layer (3) are embedded in the accelerator coating layer (4).

2. The cyclotron ionizing radiation self-shielding device of an off-yoke isotope target system of claim 1, wherein: the left side shield body (5) and the right side shield body (6) are respectively provided with an accommodating cavity for accommodating the cyclotron (1), the upper part of the accommodating cavity is a top cover (14) coated on the top of the cyclotron (1), and the inner edge (15) of the top cover (14) of the left side shield body (5) can be spliced with the inner edge (15) of the top cover (14) of the right side shield body (6).

3. The cyclotron ionizing radiation self-shielding device of an off-yoke isotope target system of claim 2, wherein: the inner edges (15) of the top covers (14) of the left side shielding body (5) and the right side shielding body (6) are respectively provided with mutually matched step surfaces, and the edge lines (16) of the inner edges (15) of the top covers (14) are convex-concave.

4. The cyclotron ionizing radiation self-shielding device of an isotope target system outside a magnet yoke according to any one of claims 1 to 3, wherein: the left shield (5) and the right shield (6) of the accelerator coating layer (4) are made of boron-containing steel fiber concrete, and the mass percentage of boron is 5%.

5. The cyclotron (1) of an external magnet yoke isotope target system of any claim 1 to 3 is provided with a self-shielding device for ionizing radiation, which is characterized in that: the boron-containing polyethylene shielding layer (3) is made of a boron-containing polyethylene composite material, and the mass percentage of boron is 3-5%; the lead shielding layer (2) is made of lead.

6. The cyclotron ionizing radiation self-shielding device of an isotope target system outside a magnet yoke according to any one of claims 1 to 3, wherein: left side shield (5), right side shield (6) are all made rectilinear movement along track (12) of laying in basic ground (13) through the drive arrangement drive, and drive arrangement is including installing in the driving motor, driving wheel group (8), driven wheelset (9) of left side shield (5) or right side shield (6) bottom, and driving motor and driving wheel group (8) are connected mutually in the transmission, and driving motor drive driving wheel group (8), driven wheelset (9) are along track (12) synchronous roll.

7. The cyclotron ionizing radiation self-shielding device of an off-yoke isotope target system of claim 6, wherein: foundation ground (13) upper berth is equipped with three tracks (12) that are parallel to each other, and a set of initiative wheelset (8), two sets of driven wheelset (9) are all installed to left side shield (5), right side shield (6) bottom, and initiative wheelset (8) roll along a track (12) in the middle of, and two sets of driven wheelset (9) are respectively along two tracks (12) of preceding, rear side and roll, and three tracks (12) are P43 heavy rail, and initiative wheelset (8), driven wheelset (9) are the bearing gyro wheel, driving motor is inverter motor.

8. The cyclotron ionizing radiation self-shielding device of an off-yoke isotope target system of claim 7, wherein: and the positions close to the end parts of the two ends of the track (12) are respectively provided with a limit buffer (10) and a limit switch, wherein the limit buffer and the limit switch correspond to the left side shield (5) and the right side shield (6), the limit switch is connected with a controller of the variable frequency motor, and the limit switch is a photoelectric limit switch or a mechanical limit switch.

9. The cyclotron ionizing radiation self-shielding device of an off-yoke isotope target system of claim 8, wherein: the buffer part of the limiting buffer (10) is made of polyurethane material, and the limiting support of the limiting buffer (10) is formed by welding steel plates.

10. The cyclotron ionizing radiation self-shielding device of an off-yoke isotope target system of claim 6, wherein: and the tops of the left side shield body (5) and the right side shield body (6) are respectively provided with a lifting hook (11).

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