A sealing transmission rod for self-sealing and protecting the stripping film of heavy ion accelerator storage chamber

Abstract

The present invention discloses a sealing transmission rod for self-sealing and protecting a stripping film in a heavy ion accelerator storage chamber, wherein the front end of the transmission rod is connected to a film clamping assembly for replacing a film, and the transmission rod is connected to a sealing assembly at the rear of the film clamping assembly, and when the front end of the transmission rod extends into a diode iron vacuum chamber, the sealing assembly is located in a diode iron vacuum pipe of a synchrotron, and one end of the diode iron vacuum pipe is connected to the diode iron vacuum chamber and the other end is connected to a stripping film storage chamber; the sealing assembly is used to seal and separate the two sections of the diode iron vacuum pipe chambers before and after the sealing assembly, and then separate the diode iron vacuum chamber and the stripping film storage chamber. The base and the sealing ring are low in cost, convenient for production and procurement, and reduce the equipment construction cost; the sealing structure is simple, the sealing effect is outstanding, and the complexity of the equipment can be greatly reduced, thereby improving the reliability of the equipment and the construction and maintenance costs.

Description

Technical Field

[0001] The invention belongs to the technical field of heavy ion accelerators, and in particular relates to a sealing transmission rod for self-sealing and protecting a stripping film of a heavy ion accelerator storage chamber. Background Art

[0002] HIMM (Heavy Ion Medical Machine) is my country's first carbon ion therapy device with independent intellectual property rights. Its main parts include an isochronous cyclotron injector, a synchrotron accelerator with an acceleration energy of up to 400 MeV, and a beam transmission line connected to five treatment terminals.

[0003] The synchrotron uses a stripping injection method, which uses C 5+ Ions bombard the carbon film (stripping film) to strip off its last extranuclear electron, transforming it into C 6+ To ensure the efficiency of beam injection into the synchrotron, the thickness of the carbon film is only 15μg / cm 2 (about 0.1μm), which is made of brittle material, and even a slight disturbance may cause the carbon film to break. Therefore, in order to ensure the long-term and effective operation of the accelerator device, the stripping film system is designed with a stripping film storage chamber to store 12 spare carbon films, which is convenient for replacement when the carbon film is damaged. The stripping film storage chamber is connected to a carbon film replacement device (reference patent CN202110462833.X).

[0004] During the long-term operation of the accelerator, the overall vacuum environment of the device was damaged due to unexpected factors such as equipment failure. Gas quickly entered the accelerator vacuum pipeline through the leak, and the disturbed airflow impacted the carbon film in use and the spare carbon film in the storage room, causing all the carbon films to be damaged, resulting in a major accident.

[0005] After such an accident occurs, the maintenance work of the accelerator will be very heavy, requiring replacement of the carbon film, installation and calibration, leak detection and evacuation, etc. Moreover, such a thin carbon film cannot be stored for a long time in a normal pressure environment, and the requirements for the staff who replace the carbon film are extremely high, so professional personnel are required to replace the carbon film. This causes a significant increase in the maintenance time and labor costs of the accelerator, especially for the synchrotron accelerator of the carbon ion therapy device.

[0006] At present, most of the stripping film systems adopt the isolation measure, that is, during the operation of the accelerator, the spare carbon film in the storage room is moved along with the film rack through the motion mechanism. After the movement is completed, the main accelerator system is isolated by a valve. The existing isolation protection device has the following problems:

[0007] 1. It is necessary to insert transmission mechanisms such as gear racks or screw bellows, as well as various photoelectric and mechanical limit protection devices into the diode vacuum pipe. This method not only has problems such as complicated equipment, cumbersome debugging, and low operating fault tolerance; in addition, the above-mentioned equipment inserted into the vacuum chamber must also meet the ultra-high vacuum access requirements, and some components have to be customized products, resulting in a significant increase in cost, time, manpower, and process costs;

[0008] 2. The existing isolation protection device usually uses magnetic fluid as the transmission and sealing device. The sealing principle of magnetic fluid will cause chaotic magnetic fields of various orders to appear around it. Therefore, the use of magnetic fluid devices in synchrotron accelerators will inevitably cause two problems: the various magnetic fields of the magnetic fluid affect the field uniformity of the dipole magnet of the synchrotron accelerator; the high field strength of the dipole magnet affects the magnetic field distribution of the magnetic fluid, resulting in sealing failure;

[0009] 3. In the existing partition protection device, when the film clamping assembly is inserted into the diode iron vacuum, the spare carbon film in the storage room must be moved to the isolation room. This process requires the film frame attached to the carbon film to move smoothly and slowly, which has high requirements for operators and control procedures. In addition, during the movement, the vibration will also be transmitted to the diode iron end of the synchrotron along with the mechanical parts, causing the accuracy of the magnet positioning to exceed the design index. Summary of the invention

[0010] The present invention provides a sealing transmission rod for self-sealing and protecting a peeling film of a heavy ion accelerator storage chamber, aiming to solve the problem that the partition equipment between the existing heavy ion synchrotron system and the storage chamber is relatively complex, occupies a large space, is difficult to operate, and has a high risk of equipment failure.

[0011] To this end, the present invention adopts the following technical solutions:

[0012] A sealing transmission rod for self-sealing and protecting a stripping film in a heavy ion accelerator storage chamber, wherein the front end of the transmission rod is connected to a diaphragm clamping assembly for replacing a diaphragm, and the transmission rod is connected to a sealing assembly at the rear of the diaphragm clamping assembly. When the front end of the transmission rod extends into a diode iron vacuum chamber, the sealing assembly is located in a diode iron vacuum pipe of a synchrotron, one end of the diode iron vacuum pipe is connected to the diode iron vacuum chamber, and the other end is connected to a stripping film storage chamber; the sealing assembly is used to seal and separate the diode iron vacuum pipes on the front and rear sides of the sealing assembly, thereby separating the diode iron vacuum chamber and the stripping film storage chamber.

[0013] Furthermore, the sealing assembly includes a disc-shaped base, the inner diameter of the base is equal to the outer diameter of the transmission rod, and the outer diameter is smaller than the inner diameter of the diode vacuum pipe; the base is fixed on the transmission rod, and a first sealing ring is provided on the inner ring of the base, and the first sealing ring is used to seal the gap between the outer circumference of the transmission rod and the inner ring of the base; a second sealing ring is provided on the outer ring of the base, and the second sealing ring is used to seal the gap between the inner cavity of the diode vacuum pipe and the outer ring of the base.

[0014] Furthermore, the first sealing ring includes at least one, and the second sealing ring includes at least two.

[0015] Furthermore, the first sealing ring is an O-ring, and the second sealing ring is a rectangular sealing ring.

[0016] Furthermore, the first sealing ring and the second sealing ring are made of fluororubber.

[0017] Furthermore, the air permeability of the first sealing ring and the second sealing ring is not greater than 3.6×10 -4 / Pa·L·cm -1 ·s -1 .

[0018] Furthermore, the gas outflow rate of the first sealing ring and the second sealing ring is not greater than 3.5×10 -4 Pa·L·cm -2 ·s -1 .

[0019] Furthermore, the base is made of aluminum alloy.

[0020] Furthermore, a plurality of screw holes pointing to the axis are formed on the outer surface of the base, and top screws are connected in the screw holes, and the base is fixed on the transmission rod through the top screws.

[0021] The beneficial effects of the present invention are:

[0022] 1. The topologically optimized base is used, and double-layer self-sealing and radial sealing are used to separate the spare carbon film in the stripping film system storage room from the diode iron vacuum chamber; the spare carbon film is protected from the airflow disturbance entering the vacuum pipeline from the leakage point, so that the operator has sufficient time to complete the separation of the stripping film system from the main accelerator system, and prevent the airflow disturbance caused by the destruction of the accelerator vacuum environment, which will cause damage to the spare carbon film; after the synchrotron accelerator is troubleshooted, it can be quickly restored to use, greatly reducing the maintenance cost and maintenance time of the synchrotron accelerator, and the operation is simple and convenient;

[0023] 2. The base and sealing ring are low-cost, easy to produce and purchase, and reduce the equipment construction cost; the sealing structure is simple and the sealing effect is outstanding, which can greatly reduce the complexity of the equipment, thereby improving the reliability of the equipment and the construction and maintenance costs;

[0024] 3. When upgrading a treatment device that is under construction or has been completed, there is no need to make design changes to the original equipment. The upgrading of the stripping membrane system can be completed by simply installing the sealing assembly of the present invention on the transmission rod, which is convenient for maintenance and upgrading of the equipment under construction and completed, and reduces the upgrading cost;

[0025] 4. This device does not introduce new magnetic fields and mechanical vibrations based on the original equipment, preventing the magnetic field and mechanical vibrations from affecting the operating accuracy of the accelerator main equipment, ensuring the safe and reliable operation of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a structural front view of the synchrotron system of the present invention;

[0027] Figure 2 yes Figure 1 A top view of

[0028] Figure 3 is a connection schematic diagram of the sealing assembly of the present invention;

[0029] Figure 4 It is a three-dimensional assembly diagram of the sealing gun head of the present invention;

[0030] In the figure: 1-stripping film storage chamber, 2-diode iron vacuum pipe, 3-diode iron vacuum chamber, 4-sealing assembly, 41-diaphragm clamping assembly, 42-base, 43-first sealing ring, 44-second sealing ring, 45-top screw, 5-transmission rod. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the accompanying drawings:

[0032] A sealing transmission rod for self-sealing and protecting the stripping film of a heavy ion accelerator storage chamber. The front end of the transmission rod 5 is connected to a diaphragm clamping assembly 41 for replacing the diaphragm. The detailed structure of the synchrotron accelerator, the transmission rod 5 and the diaphragm clamping assembly 41 can be found in patent CN202110462833.X, which will not be repeated here.

[0033] The transmission rod 5 is connected to the sealing component 4 at the rear of the film clamping component 41. When the front end of the transmission rod 5 extends into the diode iron vacuum chamber 3, the sealing component 4 is located in the synchrotron diode iron vacuum pipe 2. Since one end of the diode iron vacuum pipe 2 is connected to the diode iron vacuum chamber 3 and the other end is connected to the stripping film storage chamber 1, the sealing component 4 can seal and separate the two sections of the diode iron vacuum pipe 2 chambers before and after the sealing component 4, thereby separating the diode iron vacuum chamber 3, i.e., the main accelerator vacuum system, and the stripping film storage chamber 1.

[0034] The sealing assembly 4 includes a disc-shaped base 42, which is preferably made of 7075 aluminum alloy to ensure that the mass of the entire base 42 does not exceed 50g. The inner diameter of the base 42 is equal to the outer diameter of the transmission rod 5, and the outer diameter is smaller than the inner diameter of the diode vacuum pipe 2 (the inner diameter of the diode vacuum pipe 2 is φ53mm, and the outer diameter of the base is φ52mm); the base 42 is sleeved and fixed on the transmission rod 5, and the outer surface of the base 42 is provided with a plurality of screw holes pointing to the axis, and the screw holes are connected with top screws 45, and the base 42 is fixed to the transmission rod 5 through the top screws 45. A first sealing groove is provided on the inner ring of the base 42, and a first sealing ring 43 is connected in the first sealing groove. The first sealing ring 43 is used to seal the gap between the outer circumference of the transmission rod 5 and the inner ring of the base 42. A second sealing groove is provided on the outer ring of the base 42, and a second sealing ring 44 is connected to the second sealing groove. The second sealing ring 44 is used to seal the gap between the inner cavity of the diode vacuum pipe 2 and the outer ring of the base 42. The number of the first sealing ring 43 and the second sealing ring 44 can be reasonably selected according to actual working conditions. In the present invention, one first sealing ring 43 is provided, and two second sealing rings 44 are provided.

[0035] In order to improve the sealing effect, the sealing ring must meet the following requirements:

[0036] 1. Since the fluororubber sealing ring has excellent high temperature resistance, excellent aging resistance, excellent chemical stability and excellent mechanical properties, the first sealing ring 43 and the second sealing ring 44 are made of fluororubber;

[0037] 2. To prevent the inner ring of the base 42 from being fixedly connected to the transmission rod 5 and there being no relative displacement between them, the first sealing ring 43 is an O-shaped sealing ring; the second sealing ring 44 is arranged on the outer ring of the base 42, and the second sealing ring 44 needs to slide back and forth relative to the diode vacuum pipe 2. To prevent the second sealing ring 44 from escaping from the second sealing groove, the second sealing ring 44 is a rectangular sealing ring;

[0038] 3. To meet the requirements of vacuum sealing, the air permeability of the first sealing ring 43 and the second sealing ring 44 is not greater than 3.6×10 -4 / Pa·L·cm -1 ·s -1 , the gas outflow rate is not more than 3.5×10 -4 Pa·L·cm -2 ·s -1 , can meet the vacuum degree 10 -5 -10 -7 Normal use under Pa conditions.

[0039] This structure completes the separation of the dipole iron vacuum chamber 3, i.e. the vacuum system of the main accelerator, and the vacuum system of the stripping film storage chamber 1. After simulation and test analysis, when the vacuum environment of the main accelerator is destroyed, the vacuum degree of the stripping film system will be reduced from the original state of 1e10-5 Pa drops to 0Pa. During this period, the operating personnel have enough time to carry out emergency repairs, which mainly include isolating the leak location of the accelerator device from the main accelerator system, moving the membrane clamping assembly 41 back to the initial position, separating the stripping membrane system from the main accelerator system, and then solving the problem of the faulty part. Since the lightweight protection device protects the spare carbon film in the storage room, it is only necessary to replace the damaged carbon film (the carbon film originally inserted into the diode iron vacuum chamber) to complete the recovery of the system.

Claims

1. A sealing transmission rod for self-sealing and protecting a stripping film in a heavy ion accelerator storage chamber, wherein the front end of the transmission rod (5) is connected to a film clipping assembly (41) for replacing the stripping film, It is characterized in that The transmission rod (5) is provided with a sealing assembly (4) at the rear of the film clamping assembly (41); when the front end of the transmission rod (5) extends into the diode iron vacuum chamber (3), the sealing assembly (4) is located in the diode iron vacuum pipe (2) of the synchrotron; one end of the diode iron vacuum pipe (2) is connected to the diode iron vacuum chamber (3) and the other end is connected to the stripping film storage chamber (1); the sealing assembly (4) is used to seal and separate the diode iron vacuum pipes (2) at the front and rear sides of the sealing assembly (4), thereby separating the diode iron vacuum chamber (3) and the stripping film storage chamber (1); The sealing assembly (4) comprises a disc-shaped base (42), the inner diameter of the base (42) being equal to the outer diameter of the transmission rod (5) and the outer diameter being smaller than the inner diameter of the diode vacuum pipe (2); the base (42) being fixed on the transmission rod (5), the inner ring of the base (42) being provided with a first sealing ring (43), the first sealing ring (43) being used to seal the gap between the outer circumference of the transmission rod (5) and the inner ring of the base (42); the outer ring of the base (42) being provided with a second sealing ring (44), the second sealing ring (44) being used to seal the gap between the inner cavity of the diode vacuum pipe (2) and the outer ring of the base (42).

2. The sealing transmission rod of the self-sealing protective heavy ion accelerator storage chamber stripping film according to claim 1, It is characterized in that The first sealing ring (43) includes at least one, and the second sealing ring (44) includes at least two.

3. The sealing transmission rod of the self-sealing protective heavy ion accelerator storage chamber stripping film according to claim 2, It is characterized in that The first sealing ring (43) is an O-shaped sealing ring, and the second sealing ring (44) is a rectangular sealing ring.

4. The sealing transmission rod of the self-sealing protective heavy ion accelerator storage chamber stripping film according to claim 3, It is characterized in that The first sealing ring (43) and the second sealing ring (44) are made of fluororubber.

5. The sealing transmission rod for the self-sealing protection stripping film of the heavy ion accelerator storage chamber according to claim 4, It is characterized in that The air leakage rates of the first sealing ring (43) and the second sealing ring (44) are not greater than 3.6×10 -4 / Pa·L·cm -1 ·s -1 .

6. The sealing transmission rod of the self-sealing protective heavy ion accelerator storage chamber stripping film according to claim 5, It is characterized in that The gas outflow rate of the first sealing ring (43) and the second sealing ring (44) is not greater than 3.5×10 -4 Pa·L·cm -2 ·s -1 .

7. The sealing transmission rod of the self-sealing protective heavy ion accelerator storage chamber stripping film according to claim 6, It is characterized in that The base (42) is made of aluminum alloy.

8. The sealing transmission rod of the self-sealing protective heavy ion accelerator storage chamber stripping film according to claim 7, It is characterized in that The outer surface of the base (42) is provided with a plurality of screw holes pointing to the axis, and top screws (45) are connected in the screw holes. The base (42) is fixed to the transmission rod (5) via the top screws (45).

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