Double-station multi-energy H2 < + > stripping and leading-out device

Abstract

The invention discloses a double-station multi-energy H2 < + > stripping and leading-out device, which comprises a multi-station stripping target and a T-shaped pluggable target head, wherein the multi-station stripping target is arranged in a valley region of an accelerator, and the same stripping target is symmetrically inserted at 45 degrees; the T-shaped pluggable target head is arranged on the multi-station stripping target; according to the multi-station stripping target, an existing magnet yoke is used for opening a hole, the stripping target is inserted at two working positions A and B which are symmetrical at 45 degrees in a time-sharing mode, and a stripping point of each station is determined according to a reference center point and a transmission matrix; wherein the station B is used for stripping and leading out high-energy beams, and the station A is used for stripping and leading out low-energy beams; according to the T-shaped pluggable stripping target head, a vertical T-shaped slot is formed in a target rod, and a vertical T-shaped insertion plate is arranged on the target head. According to the invention, the extraction of the multi-energy high-current proton beam is realized, and breakthrough is realized: the flexibility of the accelerator is obviously improved, so that the accelerator can provide two types of high-current proton beam energy, and wider application requirements are met.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of cyclotrons, and particularly relates to a double-station multi-energy H2 + stripping extraction device. BACKGROUND

[0002] High-current proton beams play an important role in the production of medical radionuclides and the research and development of new-generation high-temperature superconducting tapes, and the stripping extraction of H2 + is an effective means for superconducting cyclotrons to generate variable-energy high-current proton beams, and its design and research have important scientific significance and application value.

[0003] At present, the stripping extraction devices of cyclotrons that strip H2 + to extract high-current proton beams are mostly single-station, and the extracted proton beams are also single-energy, and there is no multi-energy, multi-station stripping extraction device that can provide high-current proton beams, which makes it difficult to take advantage of the variable-energy beam provided by stripping extraction.

[0004] If a single-station stripping extraction device is used to extract multiple-energy high-current proton beams, a de-energizer is generally arranged outside the accelerator to achieve the extraction of more than two energies. However, the de-energizer is suitable for occasions with a large de-energization range, for example, from 230 MeV to 70 MeV. If the de-energization range is very small and only a few de-energization ranges are used, the de-energizer is not economical enough.

[0005] If a single-station stripping extraction device is used to extract more than two-energy high-current proton beams without using a de-energizer, the following problems may exist:

[0006] Due to the limitation of the single station, when a station extracts more than two energies, the beam orbit of the second and subsequent extractions is prone to interfere with the stripping extraction device of the single station and is difficult to adjust. Or under the limitation of the single station, when a station extracts more than two energies, the beam orbit of the second and subsequent extractions is rotated one or more times, and the extraction point does not extract at the specified extraction port but hits other places. SUMMARY

[0007] The present application proposes a double-station multi-energy H2 + stripping extraction device to solve the problems of the prior art. The purpose is to solve the problem that when a single station extracts more than two energies, the beam orbit of the second and subsequent extractions is prone to interfere with the stripping extraction device and is difficult to adjust, or the beam orbit of the second and subsequent extractions is rotated one or more times, and the extraction point does not extract at the specified extraction port but hits other places.

[0008] The application adopts the following technical solutions to solve its technical problems:

[0009] A double-station multi-energy H2+ stripping extraction device, characterized in that it comprises the following structures: a 45° symmetrically inserted multi-station stripping target in a valley region of an accelerator, which is a same stripping target; and a "T-shaped" plug-in type target head on the multi-station stripping target; the multi-station stripping target is inserted in two 45° symmetric working positions A and B by time sharing by using an existing magnetic yoke opening, and a stripping point of each station is determined according to a reference center point and a transmission matrix; the A station performs stripping extraction of a high-energy beam, and the B station performs stripping extraction of a low-energy beam; the "T-shaped" plug-in type stripping target head is a vertical "T-shaped" slot on a target rod and a vertical "T-shaped" plug on the target head.

[0010] Further, the multi-station stripping target is inserted in two 45° symmetric working positions A and B by time sharing by using an existing magnetic yoke opening, and the specific process is as follows: if high-energy proton beam is to be extracted, the stripping target is assembled at the A station; if low-energy proton beam is to be extracted, the stripping target is disassembled from the A station and assembled at the B station, so that multi-energy stripping extraction is realized by using the original multi-station magnetic yoke opening.

[0011] Further, the stripping point of each station is determined according to the reference center point and the transmission matrix, and the specific process is as follows:

[0012] 1) setting a reference center point of a high-energy and a low-energy to be extracted and a focusing element to be extracted;

[0013] 2) determining a transmission trajectory of different energy beams according to a basic beam optical transmission theory, the trajectory being represented by a transmission matrix;

[0014] 3) determining a stripping point of each station according to the reference center point and the transmission matrix, the stripping point position being represented by (θ, R).

[0015] Further, when the reference center point of the focusing element to be extracted is (R, θ) = (840.5 mm, 53.09°), the high energy is 9 MeV, and the low energy is 6.5 MeV, the reference stripping point of the A station is (337.2, 160.3°), and the reference stripping point of the B station is (411.1, 200.1°).

[0016] Further, when the reference center point of the focusing element to be extracted is (θ, R) = (840.5 mm, 53.09°), and the high energy is 9 MeV, the transmission matrix of the A station stripping point is:

[0017]

[0018] When the reference center point of the focusing element is (θ, R) = (840.5 mm, 53.09°) and the low energy is 6.5 MeV, the transmission matrix of the stripping point at station B is:

[0019]

[0020] Furthermore, the "T-shaped" plug-in stripping target head has an additional layer of copper sheets at the top and bottom positions to collect residual electrons after stripping, ensuring that the stripped electrons are not lost; and a pair of screws for mounting wires are set on the target head to fix the wires to the target head. The wires accurately reflect the number of stripped electrons, and the number of electrons reflects whether the target head has reached the predetermined stripping position.

[0021] Advantages and effects of the present invention

[0022] 1. The effective benefits of this invention are: by designing a dual-station, multi-energy H2... + The stripping extraction device utilizes existing magnetic yoke openings to insert the stripping target at two symmetrical 45° working positions. The target can be moved, disassembled, and assembled between these positions. Combined with an H-shaped stripping target head that can change direction, it can extract beams of different energies while avoiding interference between the extracted beam trajectories and the stripping extraction device. It also ensures that beams of different energies are extracted with as few rotations as possible. This design avoids the high engineering difficulty and poor economic efficiency of traditional stripping extraction devices with six-dimensional motion capabilities. By utilizing existing structural designs, a dual-position insertion stripping extraction device combined with a pad that allows the target head to rotate at a certain angle achieves highly economical multi-energy H2 extraction. + Stripping the extraction device. Stripping H2 + The extracted variable-energy high-current proton beam can be used for the production of medical radionuclides, and has broad application prospects.

[0023] 2. A breakthrough in achieving the extraction of multi-energy, high-current proton beams: By setting up two switchable stripping target stations (A and B) in a valley region, and utilizing the acceleration characteristics of negative hydrogen ions (H-→H... 0 →p + This allows the beam to be stripped at different locations (corresponding to different cumulative cycles / energy), resulting in two proton beams with different energies. This significantly improves the accelerator's flexibility, enabling it to provide two high-current proton beam energies to meet a wider range of application needs, such as irradiation at different depths, multi-energy point experiments, and treatment planning.

[0024] 3. Solve the problem of beam orbit interference: Through the design of double stations, it allows independent optimization and accurate setting of a stripping point for each target energy beam (A station corresponds to energy E_A, B station corresponds to energy E_B). Each stripping point is located on the ideal orbit of the corresponding energy beam. Avoid the risk of beam orbit interference with stripping devices or other key components. When E_A energy beam is needed to be extracted, only A station target is used; when E_B is extracted, only B station target is used. The extraction orbits of the two beams are separated in space (especially near the stripping point), and do not interfere with each other, greatly improving the stability and reliability of the system.

[0025] 4. Ensure that the extraction point is in the specified position: Through accurate beam optical calculation and engineering design, A station target and B station target are respectively positioned at the ideal stripping point of the corresponding energy beam. This means that after the beam with energy E_A is stripped at A point, or the beam with energy E_B is stripped at B point, their subsequent deflection trajectories in the magnetic field can accurately guide to the same extraction exit entrance position. It ensures that no matter whether it is running in A station or B station, the extracted beam can accurately and efficiently enter the downstream beam transport line, avoiding beam loss and system instability. This is a necessary condition for stable and efficient multi-energy extraction.

[0026] 5. Take full advantage of the advantages of stripping extraction to provide variable energy beam: The double station design successfully combines the "fast switching" advantage of stripping extraction with the "multi-energy" capability. It breaks through the fundamental limitation of single station that can only provide single energy. It truly releases the great potential of stripping extraction technology in providing flexible, fast switching multi-energy high current proton beam. This makes the accelerator better serve advanced application fields that require multiple energy beams, such as proton therapy (different tumor depths), material irradiation research (different damage depths), multi-energy point physics experiments, etc. The potential of the device is maximized. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1a It is a top view of the double station target head of the present application;

[0028] Figure 1b It is a perspective view of the double station target head of the present application;

[0029] Figure 2 It is a beam trajectory diagram of the double station target head of the present application;

[0030] Figure 3 It is a polar coordinate diagram of the stripping point of the double station target head of the present application;

[0031] Figure 4 It is a "T-shaped" plug-in stripping target head diagram of the present application. DETAILED DESCRIPTION

[0032] Design principle of the present application

[0033] 1. Innovation of the present application:

[0034] Innovation point one: double-station multi-energy stripping extraction technology: the double-station stripping extraction architecture is created for the first time, breaking through the limitation of single station and single energy extraction of traditional cyclotrons. Through time-sharing multiplexing of two stripping target stations located at the 45° symmetric positions (A / B) of the accelerator, flexible extraction of high and low dual-energy high-current proton beams is realized, significantly improving the flexibility of beam application. Innovation point two: magnetic yoke opening reuse technology: the existing magnetic yoke is innovatively used for symmetric opening to realize dual-energy extraction. By switching the same stripping target mechanism between the 45° symmetric A and B stations (corresponding to different energy ring beams, respectively), the need for additional openings is eliminated, the structural integrity of the magnetic yoke is maximized, and the engineering complexity and manufacturing cost are reduced. Innovation point three: "T" shape quick-change target head design: an integrated "T" shape plug-in target head is adopted, which has high-precision positioning and quick switching functions. The unique structure ensures the repeatability of the target head when moving between A / B stations, enabling millisecond-level reliable switching between different energy beam extraction states. Innovation point four: integrated electronic monitoring and positioning system: innovative integration of electronic collection and beam position monitoring functions: electronic collection: copper sheets are added above and below the target head to efficiently capture residual electrons from stripping, preventing electron cloud interference with accelerator operation. Beam positioning and monitoring: by measuring the electronic current conducted by the target head screw in real time, the spatial position of the target head is accurately inverted non-invasively, and online monitoring and closed-loop control of the beam hitting position are simultaneously realized.

[0035] 2. Design principle of the present application:

[0036] 1. Double-station stripping target (core innovation): Position: Two working positions (A station and B station) are set in the valley region of the accelerator ring structure with 45° symmetry. Function: The same stripping target can be inserted or removed from these two positions by mechanical means. Energy correspondence: A station (high energy): when the beam reaches high energy, the stripping target is inserted into the A station. High-energy proton beams hit the stripping target here, stripping off electrons (forming negative hydrogen ions H-), and converting into positive protons (H + ). Due to the change in the action of the magnetic field, the high-energy proton beam is deflected and extracted. B station (low energy): when low-energy beam extraction is needed (usually in the early stage of the acceleration cycle), the same stripping target is inserted into the B station. Lower-energy proton beams are stripped here, converted into positive protons, and deflected and extracted.

[0037] 2. Multiplexing yoke holes (cost reduction / compatibility): The existing accelerator magnet structure (yoke) already has multiple holes (possibly reserved for other purposes or inherently a multi-period structure). Instead of digging new holes, the design will assemble or disassemble the stripping target assembly to the corresponding, existing yoke hole locations, according to the energy to be extracted (selecting either A or B station), achieving a clever use of the existing physical space.

[0038] 3. Stripping point precise positioning based on transport matrix (beam optical design): Input setting: Clearly specify the high and low energy values to be extracted, and the reference center point positions of the magnetic elements responsible for the extraction beam focusing and guiding. Transport calculation: Apply the basic theory of beam optics (especially the transport matrix method) to calculate the ideal transport trajectory of the proton beam in the specific region of the accelerator (including the extraction element). Stripping point determination: For the selected station (A or B), combined with the reference center point of this position and the calculated transport matrix of the beam at this energy, the exact position (i.e. stripping point) within the station where the beam needs to hit the stripping target is inversely deduced to ensure that the stripped and converted into positive protons beam can accurately follow the designed extraction trajectory and be guided out of the specified extraction port. This solves the problem of "extraction point not in the specified extraction port".

[0039] 4. T-shaped target head structure (reliability and diagnosis): Function: The target head of the stripping target is designed in a special T shape. Electron collection: This structure can effectively capture the electrons generated during the stripping process, preventing them from flying around and causing interference or loss. Position monitoring: By monitoring the intensity of the electron signal generated by hitting the T-shaped target head in real time, it can indirectly determine whether the stripping target has been accurately moved and positioned to the predetermined stripping point (the exact position within the A or B station). This provides an important online position feedback mechanism.

[0040] Based on the above principles, the present application designs a dual-station multi-energy H2+ stripping extraction device, as shown in Figure 1a 、 Figure 1b 、 Figure 2 、 Figure 3 、 Figure 4 , characterized by comprising the following structures: a 45° symmetrically inserted multi-station stripping target in a valley region of an accelerator, which is the same stripping target; and a "T-shaped" plug-in target head on the multi-station stripping target; the multi-station stripping target is inserted into the 45° symmetrically inserted two working positions A and B of the stripping target at different times, and the stripping point of each station is determined according to the reference center point and the transport matrix; wherein the A station performs high-energy beam stripping extraction, and the B station performs low-energy beam stripping extraction; the "T-shaped" plug-in stripping target head is a vertical "T-shaped" slot on the target rod and a vertical "T-shaped" plug-in plate on the target head.

[0041] Further, the existing magnetic yoke opening is used to insert the stripping target in two 45° symmetrical working positions A and B at different times, specifically, if high-energy proton beam is needed, the stripping target is assembled in position A; if low-energy proton beam is needed, the stripping target is disassembled from position A and assembled in position B, so that the original multi-position magnetic yoke opening is used to realize multi-energy stripping.

[0042] Further, the stripping point of each position is determined according to the reference center point and the transmission matrix, specifically:

[0043] 1) Set the reference center point of the high-energy and low-energy to be extracted and the focusing element to be extracted;

[0044] 2) According to the basic transmission theory of beam optics, the transmission trajectory of different energy beams is determined, which is represented by the transmission matrix;

[0045] 3) The stripping point of each position is determined according to the reference center point and the transmission matrix, and the stripping point position is represented by (θ, R).

[0046] Further, when the reference center point of the focusing element to be extracted is (R, θ) = (840.5mm, 53.09°), and the high-energy is 9MeV and the low-energy is 6.5MeV, the reference stripping point of position A is (337.2, 160.3°); the reference stripping point of position B is (411.1, 200.1°).

[0047] Further, when the reference center point of the focusing element to be extracted is (θ, R) = (840.5mm, 53.09°), and the high-energy is 9MeV, the transmission matrix of the stripping point of position A is:

[0048]

[0049] When the reference center point of the focusing element to be extracted is (θ, R) = (840.5mm, 53.09°), and the low-energy is 6.5MeV, the transmission matrix of the stripping point of position B is:

[0050]

[0051] Further, the "T-shaped" stripping target head is increased by one layer of copper sheets at the upper and lower positions of the target head to collect the residual electrons after stripping, ensuring that the stripped electrons are not lost; and a pair of screws for installing wires are arranged on the target head, the wires are fixed on the target head through the screws, the number of stripped electrons is accurately reflected through the wires, and whether the target head reaches the predetermined stripping position is reflected through the number of electrons.

Claims

1. A dual-station, multi-energy H2+ stripping and extraction device, characterized in that, The structure includes the following: a multi-station stripping target symmetrically inserted at 45° within a valley region of the accelerator, the multi-station stripping target being a single stripping target; and a "T-shaped" plug-in target head on the multi-station stripping target; the multi-station stripping target utilizes existing magnetic yoke openings to insert the stripping target at two symmetrical working positions A and B at 45° in a time-division manner, and determines the stripping point of each station based on the reference center point and the transmission matrix; wherein, station A performs stripping and extraction of high-energy beams, and station B performs stripping and extraction of low-energy beams; the "T-shaped" plug-in stripping target head consists of a vertical "T"-shaped slot on the target rod and a vertical "T"-shaped insert plate on the target head.

2. The dual-station, multi-energy H2+ stripping and extraction device according to claim 1, characterized in that: The method involves using existing magnetic yoke openings to insert the stripping target at two symmetrical working positions A and B at 45° in a time-division manner. Specifically, if a high-energy proton beam needs to be extracted, the stripping target is assembled at position A; if a low-energy proton beam needs to be extracted, the stripping target is disassembled from position A and moved to position B for assembly, thereby utilizing the existing multi-position magnetic yoke openings to achieve multi-energy stripping extraction.

3. The dual-station, multi-energy H2+ stripping and extraction device according to claim 1, characterized in that: The process of determining the stripping point for each workstation based on the reference center point and the transmission matrix is ​​as follows: 1) Set the high and low energies to be extracted, and the reference center point for extracting the focusing element; 2) Based on the fundamental transmission theory of beam optics, determine the transmission trajectories of beams with different energies, which are represented by the transmission matrix; 3) Determine the stripping point of each station based on the reference center point and the transfer matrix. The location of the stripping point is represented by (θ, R).

4. The dual-station, multi-energy H2+ stripping and extraction device according to claim 3, characterized in that: When the reference center point of the focusing element is (R, θ) = (840.5 mm, 53.09°), and the high energy is 9 MeV and the low energy is 6.5 MeV, the reference stripping point of station A is (337.2, 160.3°); the reference stripping point of station B is (411.1, 200.1°).

5. The dual-station, multi-energy H2+ stripping and extraction device according to claim 4, characterized in that: When the reference center point of the focusing element is (θ, R) = (840.5 mm, 53.09°) and the high energy is 9 MeV, the transmission matrix of the stripping point at station A is: When the reference center point of the focusing element is (θ, R) = (840.5 mm, 53.09°) and the low energy is 6.5 MeV, the transmission matrix of the stripping point at station B is:

6. The dual-station, multi-energy H2+ stripping and extraction device according to claim 1, characterized in that: The "T-shaped" plug-in stripping target head has an additional layer of copper sheets at the top and bottom to collect residual electrons after stripping, ensuring that the stripped electrons are not lost. In addition, a pair of screws are set on the target head to fix the wires to the target head. The wires accurately reflect the number of electrons stripped, and the number of electrons indicates whether the target head has reached the predetermined stripping position.

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