A beam measurement method based on a dynamic cyclotron central zone structure

Abstract

The application discloses a kind of based on dynamic cyclotron center zone structure beam measurement method: including the following steps: dynamic installation first center zone structure, measures the beam distribution from small radius to large radius at first beam slit position;Dynamic installation second center zone structure, measures the beam distribution from small radius to large radius at second beam slit position;Dynamic installation third center zone structure, measures the beam distribution from small radius to large radius at third beam slit position;Dynamic installation fourth center zone structure, measures the beam distribution from small radius to large radius at fourth beam slit position;The present application solves the circumferential shielding and radial shielding problem of center zone beam test by randomly installing and randomly removing beam slit plate, completes the measurement center zone each set position from small radius to large radius beam test task, solves the long-standing problem of center zone beam intensity distribution in the field cannot be measured.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of cyclotrons, and particularly relates to a beam measurement method based on a dynamic cyclotron center zone structure. BACKGROUND

[0002] In a cyclotron, the center zone refers to a transition region of a particle acceleration process from a stationary state (in the case of an internal ion source) or a low energy (in the case of an external ion source) to a certain high energy, covering the first several turns of the beam motion in the accelerator.

[0003] Because the center zone structure is complex and the beam motion is unstable, the beam loss rate of the center zone is relatively high. In the debugging process of the cyclotron, affected by non-ideal factors such as machining and installation errors, the beam loss rate of the center zone is often higher than the design value, and in some cases, the beam is completely lost in the center zone during the initial beam debugging.

[0004] The existing technology tests the beam of the center zone by regarding the center zone as a whole. When the center zone is regarded as a whole to test the beam, the measuring device or measuring position is generally placed at the outlet of the center zone. For example, a conventional method installs an internal target at the outlet of the center zone outside the center zone, and measures the beam by using the internal target.

[0005] The problem of regarding the center zone as a whole to test the beam is that only the beam intensity of the whole center zone can be measured, but the beam intensity of the local center zone cannot be measured, that is, the distribution of the beam in the center zone cannot be measured. Without the distribution, it is impossible to determine which part of the center zone has a problem. Without determining which part of the center zone has a problem, it is impossible to test the center zone in sections, and without testing the center zone in sections, it is impossible to debug the center zone in sections, which leads to the fact that the center zone can only be debugged as a whole.

[0006] The problem of debugging the center zone as a whole is that there are too many parameters affecting the beam intensity in the center zone, including more than ten parameters from the beam injection line, multiple parameters from the first high-frequency cavity, and multiple parameters from the second high-frequency cavity. At least 20 parameters are added together. Since it is not known which parameter has a problem, the 20 parameters affecting the beam intensity must be arranged and combined to check one by one when testing the beam. Assuming that the beam intensity measured by the internal target should be 100 mA, but the internal target only measures 1 mA of beam, when finding the reason, the 20 parameters affecting the beam intensity must be arranged and combined to become several hundred parameters, and the several hundred parameters must be checked one by one to find the reason for the weak beam intensity. SUMMARY

[0007] The application is a kind of beam measurement method based on dynamic cyclotron center structure, aiming at solving the problem that the prior art cannot measure the center area beam distribution.

[0008] The application is a kind of beam measurement method based on dynamic cyclotron center structure, aiming at solving the problem that the prior art cannot measure the center area beam distribution.

[0009] The application is a kind of beam measurement method based on dynamic cyclotron center structure, aiming at solving the problem that the prior art cannot measure the center area beam distribution.

[0010] The application is a kind of beam measurement method based on dynamic cyclotron center structure, aiming at solving the problem that the prior art cannot measure the center area beam distribution.

[0011] Step one, dynamically install the first center structure, measure the beam distribution from small radius to large radius at the position of the first beam slit; the first beam slit is arranged before the beam enters the first high-frequency cavity;

[0012] Step two, dynamically install the second center structure, measure the beam distribution from small radius to large radius at the position of the second beam slit; the second beam slit is arranged after the beam passes through the first high-frequency cavity;

[0013] Step three, dynamically install the third center structure, measure the beam distribution from small radius to large radius at the position of the third beam slit; the third beam slit is arranged before the beam enters the second high-frequency cavity;

[0014] Step four, dynamically install the fourth center structure, measure the beam distribution from small radius to large radius at the position of the fourth beam slit; the fourth beam slit is arranged after the beam passes through the second high-frequency cavity.

[0015] Further, the step one dynamically installs the first center structure, and measures the beam distribution from small radius to large radius at the position of the first beam slit, and the specific process is as follows:

[0016] 1) The first center structure, that is, on the basis of the initial center structure, a first beam slit is newly installed, and a second beam slit, a third beam slit, and a fourth beam slit are not installed; a first electrode column and a fifth electrode column are installed, and a second electrode column, a third electrode column, a fourth electrode column, a sixth electrode column, and a seventh electrode column are not installed;

[0017] 2) Adjust the slit position to the small radius side of the lower support of the central region, and measure the beam intensity at this time using the inner target;

[0018] 3) Move the slit position from the small radius side of the lower support of the central region to the large radius direction of the lower support of the central region gradually, and the moving step is the same as the slit width. Measure the beam intensity again using the inner target;

[0019] 4) Move the slit position and measure the flow intensity multiple times until the position of the first beam slit moves to the large radius side of the lower support of the central region, that is, the flow intensity distribution at different positions is obtained.

[0020] Further, the specific process of measuring the beam intensity distribution from the small radius to the large radius at the position of the second beam slit in the step two of dynamically installing the second central region structure is as follows:

[0021] 1) The second central region structure, that is, on the basis of the initial central region structure, the second beam slit is newly installed, and the first beam slit, the third beam slit and the fourth beam slit are not installed. The first electrode column, the fifth electrode column, the second electrode column and the third electrode column are installed, and the fourth electrode column, the sixth electrode column and the seventh electrode column are not installed;

[0022] 2) Adjust the slit position to the small radius side of the lower support of the central region, and measure the beam intensity at this time using the inner target;

[0023] 3) Move the slit position from the small radius side of the lower support of the central region to the direction of the third electrode column gradually, and the moving step is the same as the slit width. Measure the beam intensity again using the inner target;

[0024] 4) Move the slit position and measure the flow intensity multiple times until the slit position reaches the side of the third electrode column, that is, the flow intensity distribution at different positions is obtained.

[0025] Further, the specific process of measuring the beam intensity distribution from the small radius to the large radius at the position of the third beam slit in the step three of dynamically installing the third central region structure is as follows:

[0026] 1) The third central region structure, that is, on the basis of the initial central region structure, the third beam slit is newly installed, and the first beam slit, the second beam slit and the fourth beam slit are not installed. The first electrode column, the fifth electrode column, the second electrode column, the third electrode column and the fourth electrode column are installed, and the sixth electrode column and the seventh electrode column are not installed;

[0027] 2) Adjust the slit position to the small radius side of the lower support of the central region, and measure the beam intensity at this time using the inner target;

[0028] 3) Move the slit position from the small radius side of the lower support of the central region to the direction of the fourth electrode column gradually, the step length of the movement is the same as the slit width, and the beam intensity is measured again by using the inner target;

[0029] 4) The slit position is moved multiple times and the flow intensity is measured until the slit position reaches the side of the fourth electrode column, i.e., the flow intensity distribution at different positions is obtained.

[0030] Further, the step four is dynamically installing the fourth central region structure, and measuring the beam distribution from the small radius to the large radius at the position of the fourth beam slit, and the specific process is as follows:

[0031] 1) The fourth central region structure, i.e., on the basis of the initial central region structure, the fourth beam slit is newly installed, and the first beam slit, the second beam slit and the third beam slit are not installed; the first electrode column, the fifth electrode column, the second electrode column, the third electrode column, the fourth electrode column, the sixth electrode column and the seventh electrode column are installed;

[0032] 2) Adjust the slit position to the small radius side of the lower support of the central region, and measure the beam intensity at this time by using the inner target;

[0033] 3) Move the slit position from the small radius side of the lower support of the central region to the direction of the seventh electrode column gradually, the step length of the movement is the same as the slit width, and the beam intensity is measured again by using the inner target;

[0034] 4) The slit position is moved multiple times and the flow intensity is measured until the slit position reaches the side of the seventh electrode column, i.e., the flow intensity distribution at different positions is obtained.

[0035] Further, the dynamic installation of each central region electrode column is accumulated, i.e., the previously installed electrode columns are not removed until all the electrode columns are installed, and the first electrode column, the second electrode column, the third electrode column, the fourth electrode column, the fifth electrode column, the sixth electrode column and the seventh electrode column are retained in the working state of the accelerator.

[0036] Further, the dynamic installation of each beam slit is as follows: the current beam slit is removed immediately after the beam test of the current beam slit is completed; and the first beam slit, the second beam slit, the third beam slit and the fourth beam slit are not installed in the working state of the accelerator.

[0037] Further, the method for moving the slit position multiple times is as follows: a plurality of slit plates are processed, each slit plate is opened at different positions, the position of the slit is adjusted by replacing the slit plate, and the slit plate is replaced manually or by a motor.

[0038] Advantages and effects of the application

[0039] 1. The application provides a beam measurement method based on a dynamic cyclotron center structure, which realizes the distribution measurement of the beam intensity within the center area, lays a foundation for further debugging of the ion source injection system parameters and determination of the approximate range of the ion source injection system parameters through the distribution measurement of the beam from a small radius to a large radius at a first slit, lays a foundation for the preliminary debugging of the parameter range of the first high-frequency cavity and the accurate debugging of the parameters of the ion source injection system through the distribution measurement of the beam from a small radius to a large radius at a second slit, lays a foundation for the accurate debugging of the parameters of the first high-frequency cavity and the more accurate debugging of the parameters of the ion source injection system through the distribution measurement of the beam from a small radius to a large radius at a third slit, and lays a foundation for the debugging of the parameters of the second high-frequency cavity through the distribution measurement of the beam from a small radius to a large radius at a fourth slit.

[0040] 2. The application solves the problem of the test of the beam from a small radius to a large radius at each circumferential position along the center area through the random installation and random removal of the beam slit plates, removes all the beam slit plates when the test is completed, and thus solves the problem of the radial shielding of the beam before it reaches the inner target. The application retains only the electrode columns before the current test along the beam track through the cumulative installation of the electrode columns, avoids the shielding of the beam by the redundant electrode columns before the beam reaches the inner target due to the beam deviation, and thus solves the problem of the circumferential shielding of the beam before it reaches the inner target. Since the problems of the circumferential shielding and the radial shielding of the beam in the center area are solved, the beam test task from a small radius to a large radius at each set position in the center area is completed, and the problem of the long-term inability to measure the beam intensity distribution in the center area is solved. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 It is a top view of the dynamic center structure for the beam debugging of the application;

[0042] Figure 2 It is a front view of the beam slit plate of the application;

[0043] Figure 3 It is a flow chart of the beam measurement method based on the dynamic cyclotron center structure of the application;

[0044] 1: ion source lower support; 2: first high frequency cavity; 2-1: first high frequency cavity beam inlet; 2-2: first high frequency cavity beam outlet; 3: second high frequency cavity; 3-1: second high frequency cavity beam inlet; 3-2: second high frequency cavity beam outlet; 4: inner target; 5-1: first electrode column; 5-2: second electrode column; 5-3: third electrode column; 5-4: fourth electrode column; 5-5: fifth electrode column; 5-6: sixth electrode column; 5-7: seventh electrode column; 6-1: first beam slit; 6-2: second beam slit; 6-3: third beam slit; 6-4: fourth beam slit. The above first beam slit, second beam slit, third beam slit and fourth beam slit are short for first beam slit plate, second beam slit plate, third beam slit plate and fourth beam slit plate. DETAILED DESCRIPTION

[0045] The application will be further explained in combination with the accompanying drawings.

[0046] Design principle of the application

[0047] 1: The innovation point of the application is that the problem of measuring the central zone beam distribution is solved by using a dynamic central zone structure. By dynamically installing a first central zone structure, the problem of measuring the central zone beam distribution at the first slit is solved, which lays a foundation for further debugging the ion source injection system parameters and determining the approximate range of the ion source injection system parameters. By dynamically installing a second central zone structure, the problem of measuring the central zone beam distribution at the second slit is solved, which lays a foundation for preliminarily debugging the parameter range of the first high frequency cavity and accurately debugging the parameters of the ion source injection system. By dynamically installing a third central zone structure, the problem of measuring the central zone beam distribution at the third slit is solved, which lays a foundation for accurately debugging the parameters of the first high frequency cavity and more accurately debugging the parameters of the ion source injection system. By dynamically installing a fourth central zone structure, the problem of measuring the central zone beam distribution at the fourth slit is solved, which lays a foundation for debugging the parameters of the second high frequency cavity. Since the problem of measuring the central zone beam distribution is solved, a foundation is laid for segmented central zone beam debugging, which effectively improves the central zone debugging efficiency.

[0048] 2. Design difficulty of dynamic central zone structure: One of the difficulties is that when the parameters of the ion source injection system, the first high frequency cavity and the second high frequency cavity are not adjusted well at the initial stage of debugging, the beam is prone to deviation. Once the beam deviates, the beam current on the inner target or the measured beam current is very weak. If the conventional accelerator central zone structure is used, the beam deviation cannot be measured, because the conventional accelerator central zone structure includes various electrode columns. Except that the first electrode column and the fifth electrode column are installed at the head of the high frequency cavity, the beam current may deviate at any one of the second, third, fourth, sixth and seventh electrode columns and hit the electrode column, so that the beam current on the inner target cannot be measured. If the beam current cannot be measured, it is not known whether the problem is caused by the ion source injection system or the high frequency cavity. According to the traditional method, 20 parameters are combined to form hundreds of parameters, and the hundreds of parameters are checked one by one. The second difficulty is to ensure the uniformity of the beam trajectory. The uniformity means not only to ensure the correct position of a point on the beam trajectory, but also to ensure the correct position of each point on the entire trajectory. It is difficult to ensure the correct position of each point on the entire trajectory. Because the beam is controlled not only by the ion source injection system, but also by the first high frequency cavity and the second high frequency cavity during one revolution. Although the current parameters of the ion source injection system can control the correct position of the current point, it does not mean that it can automatically control the correct position of each point on the subsequent trajectory. Although the current parameters of the first high frequency cavity or the second high frequency cavity can control the correct position of the beam trajectory at the outlet, it does not mean that it can automatically control the correct position of the beam trajectory at the inlet.

[0049] 3. Solution to the first difficulty: cumulative installation of electrode columns. In order to solve the beam deviation problem, the electrode columns of the central zone structure in the working state are all removed except the first electrode column 5-1 and the fifth electrode column 5-5 at the head of the high frequency cavity, so as to avoid the shielding of the beam by the excess electrode columns. The excess electrode columns are all the electrode columns after the current beam slit along the direction of the beam trajectory. The electrode columns before the current beam slit cannot be removed and must be retained, which do not belong to the excess electrode columns. Assuming that the beam on the second beam slit 6-2 is to be tested, only the second electrode column 5-2 and the third electrode column 5-3 related to the current second beam slit 6-2 need to be installed, and the fourth electrode column 5-4, the sixth electrode column 5-6 and the seventh electrode column 5-7 after the current beam slit are excess electrode columns. The excess electrode columns may deviate in any one of the 1-4 circles of the central zone because the parameters are not adjusted well, which leads to inaccurate measurement of the beam current on the inner target 4 outside the central zone. Through the cumulative installation of the electrode columns, the beam deviation problem is solved.

[0050] 4. The solution to the second difficulty: install and remove the beam slit plate as needed. In order to solve the problem of beam uniformity, beam slit plates are installed at several special points in the central region of the beam trajectory (the positions of these special points are beam slit 6-1, beam slit 6-2, beam slit 6-3, and beam slit 6-4), and the beam slit is gradually moved from the small radius to the large radius, so that the beam from the small radius to the large radius is measured, and the beam uniformity is adjusted. At the same time, the beam slit plate is installed and removed as needed. If there is a beam slit plate in front of the current position, and the slit position of the beam slit plate in front is fixed, the beam slit plate in front will block other beams outside the slit (because the beam slit is cut in the plate, and the slit only occupies 2mm of the plate, the rest will block the beam), assuming that the slit is in the middle of the beam slit plate, then the beam slit behind cannot measure the beam from the small radius to the large radius outside the middle 2mm because the beam at the small radius and the large radius has been blocked by the beam slit plate in front. Therefore, when installing the beam slit plate, only the current beam slit plate is retained and the beam slit plate in front is removed. Through the above installation and removal of the beam slit plate, the problem of beam uniformity is solved.

[0051] Based on the above principle, the present application designs a beam measurement method based on the dynamic central region structure of the dynamic cyclotron, as shown in Figure 1 、 Figure 2 、 Figure 3 The dynamic central region structure is installed on the basis of the initial central region structure, and each central region electrode column and each beam slit is installed dynamically according to the steps of beam measurement. The basic central region structure includes: an ion source lower support body 1 fixed in the central region of the accelerator for injecting ions; a first high-frequency cavity 2 and a second high-frequency cavity 3 fixed symmetrically at 180 degrees on the ion source lower support body 1 for accelerating particles; and an inner target 4 fixed outside the central region for testing beam intensity.

[0052] The beam measurement method has the following steps:

[0053] Step one, dynamically install the first central region structure, and measure the beam distribution from the small radius to the large radius at the position of the first beam slit, which is arranged before the beam enters the first high-frequency cavity 2,

[0054] The specific process is as follows:

[0055] 1) the first central zone structure, that is, on the basis of the initial central zone structure, newly install the first beam slit 6-1, do not install the second beam slit 6-2, the third beam slit 6-3, and the fourth beam slit 6-4; install the first electrode column 5-1 and the fifth electrode column 5-5, and do not install the second electrode column 5-2, the third electrode column 5-3, the fourth electrode column 5-4, the sixth electrode column 5-6, and the seventh electrode column 5-7;

[0056] 2) adjust the slit position to the small radius side of the lower support body 1 of the central zone, and measure the beam intensity at this time by using the inner target 4;

[0057] 3) gradually move the slit position from the small radius side of the lower support body 1 of the central zone to the large radius direction of the lower support body of the central zone, the moving step is the same as the slit width, and the beam intensity is measured again by using the inner target 4;

[0058] 4) move the slit position multiple times and measure the flow intensity until the position of the first beam slit 6-1 is moved to the large radius side of the lower support body 1 of the central zone, that is, the flow intensity distribution at different positions is obtained.

[0059] Supplementary note 1

[0060] Both ends of the above-mentioned beam slit 6-1 are installed on the lower support body 1 of the central zone, one end is installed on the inner ring 1-1 of the lower support body 1 of the central zone, and the other end is installed on the outer ring 1-2 of the lower support body 1 of the central zone.

[0061] Step two, dynamically install the second central zone structure, and measure the beam intensity distribution from the small radius to the large radius at the position of the second beam slit; the second beam slit is arranged after the beam passes through the first high-frequency cavity 2;

[0062] The specific process is as follows:

[0063] 1) the second central zone structure, that is, on the basis of the initial central zone structure, newly install the second beam slit, do not install the first beam slit, the third beam slit, and the fourth beam slit; install the first electrode column, the fifth electrode column, the second electrode column, and the third electrode column, and do not install the fourth electrode column, the sixth electrode column, and the seventh electrode column;

[0064] 2) adjust the slit position to the small radius side of the lower support body of the central zone, and measure the beam intensity at this time by using the inner target;

[0065] 3) gradually move the slit position from the small radius side of the lower support body of the central zone to the direction of the third electrode column, the moving step is the same as the slit width, and the beam intensity is measured again by using the inner target;

[0066] 4) Move the slit position several times and measure the beam intensity until the slit position reaches the side of the fourth electrode column, i.e. the beam intensity distribution at different positions is obtained.

[0067] Supplementary note 2

[0068] One end of the beam slit 6-2 is installed on the inner ring 1-1 of the lower support body 1 of the central region, and the other end is installed on the electrode column 5-3.

[0069] Step three, dynamically install the third central region structure, and measure the beam intensity distribution from the small radius to the large radius at the position of the third beam slit; the third beam slit is arranged before the beam enters the second high-frequency cavity 3.

[0070] The specific process is as follows:

[0071] 1) The third central region structure, that is, the third beam slit is newly installed on the basis of the initial central region structure, and the first beam slit, the second beam slit, and the fourth beam slit are not installed; the first electrode column, the fifth electrode column, the second electrode column, the third electrode column, and the fourth electrode column are installed, and the sixth electrode column and the seventh electrode column are not installed.

[0072] 2) Adjust the slit position to the small radius side of the lower support body of the central region, and use the inner target to measure the beam intensity at this time;

[0073] 3) Move the slit position from the small radius side of the lower support body of the central region to the direction of the fourth electrode column gradually, and the step length is the same as the slit width, and the beam intensity is measured again using the inner target;

[0074] 4) Move the slit position several times and measure the beam intensity until the slit position reaches the side of the fourth electrode column, i.e. the beam intensity distribution at different positions is obtained.

[0075] Supplementary note 3

[0076] One end of the beam slit 6-2 is installed on the inner ring 1-1 of the lower support body 1 of the central region, and the other end is installed on the electrode column 5-3.

[0077] Step four, dynamically install the fourth central region structure, and measure the beam intensity distribution from the small radius to the large radius at the position of the fourth beam slit; the fourth beam slit is arranged after the beam passes through the second high-frequency cavity 3.

[0078] The specific process is as follows:

[0079] 1) the fourth central zone structure, that is, on the basis of the initial central zone structure, a fourth beam slit is newly installed, and the first beam slit, the second beam slit, and the third beam slit are not installed; the first electrode column, the fifth electrode column, the second electrode column, the third electrode column, the fourth electrode column, the sixth electrode column, and the seventh electrode column are installed;

[0080] 2) the slit position is adjusted to the small radius side of the lower support body of the central zone, and the beam intensity at this time is measured by using the inner target;

[0081] 3) the slit position is gradually moved from the small radius side of the lower support body of the central zone to the direction of the seventh electrode column, the moving step is the same as the slit width, and the beam intensity is measured again by using the inner target;

[0082] 4) the slit position is moved multiple times and the flow intensity is measured until the slit position reaches the side of the seventh electrode column, that is, the flow intensity distribution at different positions is obtained;

[0083] Supplementary note 4

[0084] Both ends of the above-mentioned beam slit 6-4 are installed on the inner ring 1-1 of the lower support body 1 of the central zone at one end and on the electrode column 5-7 at the other end.

[0085] The dynamic installation of each central zone electrode column is a cumulative dynamic installation method, that is, the previously installed electrode columns are not removed until all the electrode columns are installed, and the first electrode column, the second electrode column, the third electrode column, the fourth electrode column, the fifth electrode column, the sixth electrode column, and the seventh electrode column are retained in the working state of the accelerator.

[0086] The dynamic installation of each beam slit is a method of retaining the current and removing the previous, that is, after the beam test of the current beam slit is completed, the current beam slit is immediately removed; in the working state of the accelerator, the first beam slit, the second beam slit, the third beam slit, and the fourth beam slit are not installed.

[0087] The method for moving the slit position multiple times is as follows: multiple clamping slit plates are processed, each clamping slit plate has different slit positions, the slit position is adjusted by replacing the clamping slit plate, and the slit plate is replaced manually or by a motor.

[0088] Example One

[0089] Based on the above measurement method, the application also designs a central zone beam test method based on the central zone beam measurement method, which comprises the following steps:

[0090] Step one, the beam distribution of four slits from small radius to large radius is obtained by theoretical calculation, and the theoretical position of the maximum current of the four slits is determined respectively;

[0091] Supplementary note 5

[0092] The step one solves the problem of the maximum current position of the theoretical calculation, and the maximum current position of the theoretical calculation is used for comparison with the maximum current position of the actual measurement of the "beam measurement method based on the structure of the central region of the dynamic cyclotron".

[0093] Step two, the inner target measurement is used to ensure that the beam has been injected into the accelerator, and the specific process is as follows:

[0094] 1) On the basis of the basic central region structure, the electrode column 1 and the electrode column 5 are newly installed, and the electrode column 1 and 5 are respectively installed in the head of the high frequency cavity 1 and the high frequency cavity 2;

[0095] 2) The inner target measurement is used to measure the beam, and the parameters of the ion source injection system are adjusted to ensure that the beam has been injected into the cyclotron.

[0096] Step three, the inner target measurement is used to adjust the parameters of the ion source injection system to make the measured value of the maximum current position and the corresponding theoretical value of the beam slit 1 at the position basically consistent, thereby preliminarily determining the approximate range of the ion source injection system parameters; the specific process is as follows:

[0097] 1) On the basis of the basic central region structure, the newly installed beam slit 1 is retained, and the electrode column 1 and the electrode column 5 of the first central region structure are retained;

[0098] 2) The circumferential position of the newly installed beam slit 1 is installed in front of the beam inlet of the high frequency cavity 1; the radial position of the beam slit 1 is that the two ends are respectively fixed on the ion source lower support body;

[0099] 3) The inner target measurement is used to measure the beam, and the parameters of the ion source injection system are adjusted to make the measured value of the maximum current position and the corresponding theoretical value of the beam slit 1 at the position basically consistent, thereby preliminarily determining the approximate range of the ion source injection system parameters.

[0100] Step four, the inner target measurement is used to adjust the parameters of the ion source injection system and the high frequency cavity 1 to make the measured value of the maximum current position and the corresponding theoretical value of the beam slit 2 at the position basically consistent, preliminarily determine the parameter range of the high frequency cavity 1, and more accurately determine the parameters of the ion source injection system. The specific process is as follows:

[0101] 1) On the basis of the basic central zone structure, newly install electrode column 2, electrode column 3 and beam slit 2, and retain electrode column 1, electrode column 5 of the second central zone structure, remove slit 1 of the second central zone structure; the electrode column 2 and the electrode column 3 are respectively installed at the front and rear sides of the beam outlet of the high-frequency cavity one, and the beam slit 2 is installed at the rear side of the beam outlet of the high-frequency cavity one;

[0102] 2) Use the internal target to measure the beam, adjust the ion source injection system parameters and the high-frequency cavity 1 parameters to make the measured value of the position where the current is the strongest and the corresponding theoretical value of the beam slit 2 substantially consistent, preliminarily determine the parameter range of the high-frequency cavity 1, and more accurately determine the parameters of the ion source injection system.

[0103] Step five, use the internal target to measure, adjust the high-frequency cavity 1 parameters to make the measured value of the position where the current is the strongest and the corresponding theoretical value of the beam slit 3 substantially consistent, and accurately determine the parameters of the high-frequency cavity 1; the specific process is as follows:

[0104] 1) On the basis of the basic central zone structure, newly install electrode column 4 and beam slit 3, and retain electrode column 1, electrode column 5, electrode column 2, electrode column 3 of the third central zone structure, remove slit 2 of the third central zone structure; the electrode column 4 and the beam slit 3 are both installed at the front side of the beam inlet of the high-frequency cavity two.

[0105] 2) Use the internal target to measure the beam, adjust the high-frequency cavity 1 parameters to make the measured value of the position where the current is the strongest and the corresponding theoretical value of the beam slit 3 substantially consistent, and accurately determine the parameters of the high-frequency cavity 1.

[0106] Step six, use the internal target to measure, adjust the high-frequency cavity 2 parameters to make the position where the current is the strongest and the corresponding theoretical value of the beam slit 3 substantially consistent, and determine the parameters of the high-frequency cavity 2; the specific process is as follows:

[0107] 1) On the basis of the basic central zone structure, newly install electrode column 6, electrode column 7 and beam slit 4; and retain electrode column 1, electrode column 2, electrode column 3, electrode column 4, electrode column 5 of the fourth central zone structure, remove slit 3 of the fourth central zone structure; the electrode column 6 and the electrode column 7 are respectively installed at the two sides of the beam inlet of the high-frequency cavity two; and the beam slit 4 is installed at the front side of the beam inlet of the high-frequency cavity two.

[0108] 2) Use the internal target to measure the beam, adjust the high-frequency cavity 2 parameters to make the position where the current is the strongest and the corresponding theoretical value of the beam slit 3 substantially consistent, and determine the parameters of the high-frequency cavity 2.

[0109] The beam slit is made of a non-magnetic material of metal; the method for moving the beam slit includes: processing a plurality of plates, each plate has a different slit opening position, and the slit position is adjusted by replacing the plate.

[0110] The above merely provides the description and illustration of the concept of the present application, and those skilled in the art can make various modifications or supplements to the specific embodiments described or adopt similar ways to replace, as long as they do not deviate from the concept of the present application or exceed the scope defined by the present claims, which shall belong to the protection scope of the present application.

Claims

1. A beam measurement method based on a dynamic central region structure of a cyclotron, wherein the dynamic central region structure is based on an initial central region structure, and wherein each central region electrode post is dynamically installed and each beam slit is dynamically installed according to a step of the beam measurement. The basic center zone structure comprises: a lower ion source support for injecting ions fixed in the accelerator center zone; a first high-frequency cavity and a second high-frequency cavity for accelerator particles fixed symmetrically at 180 degrees on the lower ion source support; and an inner target for testing beam intensity fixed outside the center zone; The beam measurement method comprises the following steps: Step 1: dynamically installing a first center zone structure to measure the beam distribution from the small radius to the large radius at the position of a first beam slit; the first beam slit is arranged before the beam enters the first high-frequency cavity; Step 2: dynamically installing a second center zone structure to measure the beam distribution from the small radius to the large radius at the position of a second beam slit; the second beam slit is arranged after the beam passes through the first high-frequency cavity; Step 3: dynamically installing a third center zone structure to measure the beam distribution from the small radius to the large radius at the position of a third beam slit; the third beam slit is arranged before the beam enters the second high-frequency cavity; Step 4: dynamically installing a fourth center zone structure to measure the beam distribution from the small radius to the large radius at the position of a fourth beam slit; the fourth beam slit is arranged after the beam passes through the second high-frequency cavity; The dynamic installation of each center zone electrode column is an accumulative dynamic installation method, that is, the previously installed electrode columns are not removed until all the electrode columns are installed, and the first electrode column, the second electrode column, the third electrode column, the fourth electrode column, the fifth electrode column, the sixth electrode column and the seventh electrode column are retained in the working state of the accelerator; The dynamic installation of each beam slit is a method of retaining the current and removing the previous, that is, after the beam test of the current beam slit is completed, the current beam slit is immediately removed; in the working state of the accelerator, the first beam slit, the second beam slit, the third beam slit and the fourth beam slit are not installed; The method of moving the slit position multiple times is as follows: multiple slit plates are processed, each slit plate has different slit positions, the position of the slit is adjusted by replacing the slit plate, and the slit plate is replaced manually or by a motor.

2. The beam measurement method based on the structure of the central region of a dynamic cyclotron according to claim 1, characterized in that, The dynamic installation of the first center zone structure in Step 1 measures the beam distribution from the small radius to the large radius at the position of the first beam slit, and the specific process is as follows: 1) The first center zone structure is newly installed with the first beam slit based on the initial center zone structure, and the second beam slit, the third beam slit and the fourth beam slit are not installed; the first electrode column and the fifth electrode column are installed, and the second electrode column, the third electrode column, the fourth electrode column, the sixth electrode column and the seventh electrode column are not installed; 2) The slit position is adjusted to the small radius side of the lower support of the center zone, and the beam intensity at this time is measured using the inner target; 3) The slit position is gradually moved from the small radius side of the lower support of the center zone to the large radius side of the lower support of the center zone, and the step length is the same as the slit width, and the beam intensity is measured again using the inner target; 4) The slit position is moved multiple times and the beam intensity is measured until the first beam slit is moved to the large radius side of the lower support of the center zone, and the beam intensity distribution at different positions is obtained.

3. The method of claim 1, wherein the structure of the central region of the dynamic cyclotron is characterized by: The second center zone structure is installed dynamically in step two, and the beam current distribution from the small radius to the large radius at the position of the second beam current slit is measured, and the specific process is as follows: 1) The second center zone structure, that is, the second beam current slit is newly installed on the basis of the initial center zone structure, and the first beam current slit, the third beam current slit, and the fourth beam current slit are not installed; the first electrode column, the fifth electrode column, the second electrode column, and the third electrode column are installed, and the fourth electrode column, the sixth electrode column, and the seventh electrode column are not installed; 2) The slit position is adjusted to the small radius side of the lower support body of the center zone, and the beam current intensity at this time is measured by using the inner target; 3) The slit position is gradually moved from the small radius side of the lower support body of the center zone to the direction of the third electrode column, the moving step is the same as the slit width, and the beam current intensity is measured again by using the inner target; 4) The slit position is moved multiple times and the current intensity is measured until the slit position reaches the side of the third electrode column, that is, the current intensity distribution at different positions is obtained.

4. The method of claim 1, wherein the structure of the central region of the dynamic cyclotron is characterized by: The third center zone structure is installed dynamically in step three, and the beam current distribution from the small radius to the large radius at the position of the third beam current slit is measured, and the specific process is as follows: 1) The third center zone structure, that is, the third beam current slit is newly installed on the basis of the initial center zone structure, and the first beam current slit, the second beam current slit, and the fourth beam current slit are not installed; the first electrode column, the fifth electrode column, the second electrode column, the third electrode column, and the fourth electrode column are installed, and the sixth electrode column and the seventh electrode column are not installed; 2) The slit position is adjusted to the small radius side of the lower support body of the center zone, and the beam current intensity at this time is measured by using the inner target; 3) The slit position is gradually moved from the small radius side of the lower support body of the center zone to the direction of the fourth electrode column, the moving step is the same as the slit width, and the beam current intensity is measured again by using the inner target; 4) The slit position is moved multiple times and the current intensity is measured until the slit position reaches the side of the fourth electrode column, that is, the current intensity distribution at different positions is obtained.

5. The method of claim 1, wherein the structure of the central region of the dynamic cyclotron is characterized by: The fourth center zone structure is installed dynamically in step four, and the beam current distribution from the small radius to the large radius at the position of the fourth beam current slit is measured, and the specific process is as follows: 1) The fourth center zone structure, that is, the fourth beam current slit is newly installed on the basis of the initial center zone structure, and the first beam current slit, the second beam current slit, and the third beam current slit are not installed; the first electrode column, the fifth electrode column, the second electrode column, the third electrode column, the fourth electrode column, the sixth electrode column, and the seventh electrode column are installed; 2) The slit position is adjusted to the small radius side of the lower support body of the center zone, and the beam current intensity at this time is measured by using the inner target; 3) The slit position is gradually moved from the small radius side of the lower support body of the center zone to the direction of the seventh electrode column, the moving step is the same as the slit width, and the beam current intensity is measured again by using the inner target; 4) The slit position is moved multiple times and the current intensity is measured until the slit position reaches the side of the seventh electrode column, that is, the current intensity distribution at different positions is obtained.

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