Vacuum degree detection method for vacuum chamber of medical cyclotron

Abstract

The invention relates to the technical field of vacuum or sealing detection, in particular to a vacuum degree detection method for a vacuum chamber of a medical cyclotron. Firstly, the leakage rate of a vacuum chamber and the air pressure sequence of a vacuum system are obtained; analyzing an air pressure sequence by combining a vacuum pump connection sequence to obtain a vacuum pump state coefficient of the vacuum system; further obtaining the corrected indoor air pressure; acquiring a vacuum chamber state coefficient of the vacuum system according to the deviation condition of the air pressure and the leakage rate in the correction chamber relative to the corresponding preset standard; and finally obtaining the vacuum coefficient of the vacuum chamber and evaluating the vacuum degree of the vacuum chamber. Based on the multi-stage cooperative working mode of the vacuum pump in the vacuum system, the operation state of the vacuum pump is evaluated, then the measured indoor air pressure of the vacuum chamber is corrected, and then the state of the vacuum chamber is evaluated by combining the corrected indoor air pressure and the leakage condition of the vacuum chamber; and the vacuum degree of the vacuum chamber is accurately evaluated by integrating the vacuum pump operation state and the vacuum chamber state.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vacuum or sealing detection, and particularly relates to a method for detecting vacuum degree of a medical cyclotron vacuum chamber. BACKGROUND

[0002] The medical cyclotron is a device for accelerating charged particles by using the joint action of magnetic field and electric field, and is widely used in medical radiation diagnosis and treatment. In the medical cyclotron, the vacuum environment is crucial, which helps to minimize energy loss and scattering during particle acceleration, and improves the output stability and accuracy of the medical cyclotron. Therefore, it is crucial to detect the vacuum of the vacuum chamber of the medical cyclotron.

[0003] In the prior art, a vacuum gauge is usually used to detect the air pressure of the vacuum chamber in the medical cyclotron, and the detected air pressure is compared with a specified standard value to evaluate the vacuum degree. However, the vacuum degree of the vacuum chamber is mainly achieved by running a multi-stage vacuum pump for vacuumizing, and the vacuum pump may have faults or leaks, resulting in poor vacuumizing effect, which may interfere with the evaluation of the vacuum degree of the vacuum chamber, and may lead to misjudgment, thus reducing the accuracy of the vacuum degree detection result. SUMMARY

[0004] In order to solve the technical problem of low accuracy of the vacuum degree detection result of the vacuum chamber of the medical cyclotron in the prior art, the purpose of the present application is to provide a method for detecting the vacuum degree of the vacuum chamber of the medical cyclotron, and the technical solution is as follows: The present application provides a method for detecting the vacuum degree of the vacuum chamber of the medical cyclotron, which comprises: At the time to be detected, the leakage rate of the vacuum chamber in the vacuum system of the medical cyclotron and the air pressure sequence of the vacuum system are obtained. The air pressure sequence includes the standard atmospheric pressure at the exhaust port of the vacuum system, the indoor air pressure of the vacuum chamber in the vacuum system, and the port air pressure at each port of each vacuum pump. According to the connection sequence of the ports of the vacuum pump in the vacuum system, the relationship between the air pressures in the air pressure sequence is analyzed to obtain the state coefficient of the vacuum pump of the vacuum system. According to the indoor air pressure and the port air pressure of the vacuum pump connected to the vacuum chamber, and in combination with the state coefficient of the vacuum pump, the corrected indoor air pressure is obtained. According to the deviation of the corrected indoor air pressure from the preset air pressure and the deviation of the leakage rate from the preset leakage rate, the state coefficient of the vacuum chamber of the vacuum system is obtained. The vacuum coefficient of the vacuum chamber is obtained according to the state coefficient of the vacuum pump and the state coefficient of the vacuum chamber. The vacuum degree of the vacuum chamber at the time to be detected is evaluated according to the vacuum coefficient.

[0005] Further, the method for obtaining the air pressure sequence comprises: The vacuum system comprises at least one high vacuum pump and one low vacuum pump, wherein the suction port of the high vacuum pump is connected to the vacuum chamber, the exhaust port of the high vacuum pump is connected to the suction port of the low vacuum pump, and the exhaust port of the low vacuum pump is connected to the exhaust port of the vacuum system. The port air pressures at each port of the high vacuum pump and the low vacuum pump and the internal air pressure of the vacuum chamber are taken as sequence elements, and the sequence is sorted according to the order of gas outflow in the vacuum chamber during vacuumization to construct an air pressure sequence.

[0006] Further, the method for obtaining the vacuum pump state coefficient comprises: According to the difference between the port air pressure at the suction port and the port air pressure at the exhaust port of each vacuum pump, a state confidence parameter of each vacuum pump is obtained; and by fusing the state confidence parameters of all vacuum pumps, a first vacuum pump state parameter of the vacuum system is obtained. According to the difference between adjacent air pressures in the air pressure sequence, a connection state coefficient of each port connection in the vacuum system is obtained; and by synthesizing the connection state coefficients of all port connections, a second vacuum pump state parameter of the vacuum system is obtained. The product of the first vacuum pump state parameter and the second vacuum pump state parameter is taken as the vacuum pump state coefficient.

[0007] Further, the method for obtaining the first vacuum pump state parameter comprises: The air pressure difference between the port air pressure at the suction port and the port air pressure at the exhaust port of each vacuum pump is calculated; if the air pressure difference is less than 0, the state confidence parameter of the corresponding vacuum pump is set to 1; if the air pressure difference is greater than or equal to 0, the state confidence parameter of the corresponding vacuum pump is set to 0. The product of the state confidence parameters of all vacuum pumps is taken as the first vacuum pump state parameter of the vacuum system.

[0008] Further, the method for obtaining the second vacuum pump state parameter comprises: At the port connection between the suction port of the high vacuum pump and the vacuum chamber, the port air pressure of the suction port of the high vacuum pump and the internal air pressure of the vacuum chamber are taken as set elements to construct a first port air pressure set; and the ratio of the minimum value to the maximum value in the first port air pressure set is taken as a first connection state coefficient. At the port connection between the exhaust port of the high vacuum pump and the suction port of the low vacuum pump, the port air pressure of the exhaust port of the high vacuum pump and the port air pressure of the suction port of the low vacuum pump are taken as set elements to construct a second port air pressure set; and the ratio of the minimum value to the maximum value in the second port air pressure set is taken as a second connection state coefficient. A third port pressure set is constructed by taking the port pressure of the exhaust port of the low vacuum pump and the standard atmospheric pressure at the exhaust port of the vacuum system as a collective element at the port connection between the exhaust port of the low vacuum pump and the exhaust port of the vacuum system; and taking the ratio of the minimum value and the maximum value in the third port pressure set as a third connection state coefficient; The product of the first connection state coefficient, the second connection state coefficient, and the third connection state coefficient is taken as a second vacuum pump state parameter of the vacuum system.

[0009] Further, the method for obtaining the corrected indoor air pressure comprises: A constant 1 is taken as the weight of the indoor air pressure, and the vacuum pump state coefficient is taken as the weight of the port pressure of the exhaust port of the high vacuum pump. The indoor air pressure and the port pressure of the exhaust port of the high vacuum pump are weighted and averaged, and the weighted and averaged result is taken as the corrected indoor air pressure of the indoor air pressure.

[0010] Further, the method for obtaining the vacuum chamber state coefficient comprises: The air pressure difference between the corrected indoor air pressure and a preset air pressure is taken as an air pressure deviation. If the air pressure deviation is less than or equal to 0, a first vacuum chamber abnormality parameter is set to 0. If the air pressure deviation is greater than 0, the air pressure deviation is taken as the first vacuum chamber abnormality parameter. The leakage rate difference between the leakage rate and a preset leakage rate is taken as a leakage rate deviation. If the leakage rate deviation is less than or equal to 0, a second vacuum chamber abnormality parameter is set to 0. If the leakage rate deviation is greater than 0, the leakage rate deviation is taken as the second vacuum chamber abnormality parameter. The sum of the first vacuum chamber abnormality parameter and the second vacuum chamber abnormality parameter is negatively correlated, and the negatively correlated result is taken as a vacuum chamber state coefficient.

[0011] Further, the method for obtaining the vacuum coefficient comprises: The product of the vacuum pump state coefficient and the vacuum chamber state coefficient is taken as a vacuum coefficient.

[0012] Further, the method for evaluating the vacuum degree of the vacuum chamber at the to-be-detected time according to the vacuum coefficient comprises: If the vacuum coefficient is greater than or equal to a preset threshold value, it is determined that the vacuum degree of the medical cyclotron vacuum chamber is good. If the vacuum coefficient is less than the preset threshold value, it is determined that the vacuum degree of the medical cyclotron vacuum chamber is abnormal.

[0013] The application further provides a vacuum degree detection system of a medical cyclotron vacuum chamber.

[0014] The application has the following advantages: The application obtains the leakage rate of the vacuum chamber in the vacuum system of the medical cyclotron and the air pressure sequence of the vacuum system at the detection time, thereby providing an analysis basis for analyzing the state of the vacuum chamber and the vacuumizing state of the multi-stage vacuum pump in the vacuum system, analyzing the air pressure size relationship in the air pressure sequence in combination with the port connection sequence of the vacuum pump in the vacuum system, obtaining the vacuum pump state coefficient reflecting whether the running state of the vacuum pump in the vacuum system is normal, obtaining the corrected indoor air pressure in combination with the vacuum pump state coefficient according to the indoor air pressure and the port air pressure of the vacuum pump connected with the vacuum chamber, reducing the limitation of only relying on a single measurement result, and improving the reliability of the vacuum degree evaluation of the vacuum chamber, obtaining the vacuum chamber state coefficient reflecting the normal possibility of the vacuum chamber in the vacuum system according to the deviation of the corrected indoor air pressure of the vacuum chamber from the preset air pressure and the deviation of the leakage rate from the preset leakage rate from two aspects of the corrected indoor air pressure of the vacuum chamber and the leakage condition, obtaining the vacuum coefficient of the vacuum chamber according to the vacuum pump state coefficient and the vacuum chamber state coefficient, and evaluating the vacuum degree of the vacuum chamber at the detection time according to the vacuum coefficient. The application evaluates the running state of the vacuum pump based on the multi-stage cooperative working mode of the vacuum pump in the vacuum system, corrects the measured indoor air pressure of the vacuum chamber, then evaluates the state of the vacuum chamber in combination with the corrected indoor air pressure of the vacuum chamber and the leakage condition, then accurately evaluates the vacuum degree of the vacuum chamber by comprehensively considering the running state of the vacuum pump and the state of the vacuum chamber. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, and the advantages thereof, a brief introduction will be given to the drawings needed in the embodiments or the prior art description. Obviously, the drawings in the following description only show some embodiments of the application, and for those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0016] Figure 1 A flowchart of a medical cyclotron vacuum chamber vacuum degree detection method provided by an embodiment of the application; Figure 2 A flowchart of a vacuum pump state coefficient obtaining method provided by an embodiment of the application; Figure 3 A flowchart of a vacuum chamber state coefficient obtaining method provided by an embodiment of the application. Detailed Implementation

[0017] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a vacuum degree detection method for a medical cyclotron vacuum chamber according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0019] The following describes in detail, with reference to the accompanying drawings, a specific scheme for a vacuum degree detection method for a medical cyclotron vacuum chamber provided by the present invention.

[0020] Please see Figure 1 The diagram illustrates a flowchart of a vacuum degree detection method for a medical cyclotron vacuum chamber according to an embodiment of the present invention, specifically including: Step S1: At the time to be detected, obtain the leakage rate of the vacuum chamber in the vacuum system of the medical cyclotron and the gas pressure sequence of the vacuum system; the gas pressure sequence includes the standard atmospheric pressure at the exhaust port of the vacuum system, the indoor gas pressure of the vacuum chamber in the vacuum system, and the port gas pressure at each port of each vacuum pump.

[0021] To facilitate understanding of the subsequent analysis, the vacuum system of a medical cyclotron is first briefly described: The vacuum system mainly includes a vacuum chamber and multi-stage vacuum pumps. The vacuum chamber is a ring-shaped or spiral cavity in the medical cyclotron, providing a stable vacuum environment for particle cyclotron acceleration. The multi-stage vacuum pumps typically consist of several vacuum pumps connected sequentially and working in concert to gradually reduce the gas pressure in the vacuum chamber through staged evacuation, thereby obtaining a stable vacuum environment. When the medical cyclotron is running, the multi-stage vacuum pumps in the vacuum system will start running, continuously evacuating the vacuum to maintain a stable vacuum environment in the vacuum chamber.

[0022] Considering that, during the vacuumizing process, the vacuum pump far away from the vacuum chamber is used to preliminarily vacuumize, to create operating conditions for the vacuum pump close to the vacuum chamber to perform fine vacuumizing, as the gas in the vacuum chamber is gradually extracted, the gas pressure in the vacuum chamber will be smaller and smaller, and the vacuum degree will be higher and higher; the port gas pressures at the ports of the multiple-stage vacuum pump connected in sequence will also gradually decrease, the vacuum degree will increase, and the port gas pressure at the port closer to the vacuum chamber will be smaller, so there is a certain progressive relationship between the port gas pressures at the ports of the multiple-stage vacuum pump system; and considering that, if there is a certain leakage in the vacuum chamber, even if the multiple-stage vacuum pump continuously operates, it is difficult to maintain a stable vacuum environment in the vacuum chamber. Therefore, in one embodiment of the present application, the leakage rate of the vacuum chamber in the vacuum system of the medical cyclotron and the gas pressure sequence of the vacuum system are first obtained at the detection time, so as to facilitate subsequent analysis of the state of the vacuum chamber and the vacuumizing state of the multiple-stage vacuum pump in the vacuum system, and accurate evaluation of the vacuum degree in the vacuum chamber.

[0023] Preferably, in one embodiment of the present application, the method for obtaining the gas pressure sequence comprises: The vacuum system comprises at least one high vacuum pump and one low vacuum pump, wherein the gas extraction port of the high vacuum pump is connected with the vacuum chamber, the gas outlet port of the high vacuum pump is connected with the gas extraction port of the low vacuum pump, and the gas outlet port of the low vacuum pump is connected with the exhaust port of the vacuum system. The port gas pressures at each port of the high vacuum pump and the low vacuum pump, and the internal gas pressure of the vacuum chamber and the standard atmospheric pressure, are respectively taken as sequence elements, and are sorted according to the gas outflow sequence in the vacuum chamber during vacuumizing, to construct the gas pressure sequence.

[0024] As an example, a cold cathode ionization vacuum gauge is respectively installed at the gas extraction port and the gas outlet port of each vacuum pump, to measure the port gas pressures at the corresponding ports by using the cold cathode ionization vacuum gauge; then a cold cathode ionization vacuum gauge is arranged in the vacuum chamber, to collect the internal gas pressure of the vacuum chamber; at the same time, a helium mass spectrometer leak detector is used to measure the leakage rate of the vacuum chamber, and the standard atmospheric pressure outside the vacuum system is obtained; wherein the unit of the gas pressure is Pa, and the unit of the leakage rate is Pa·m³ / s. Then, the points through which the gas flows during the outflow of the gas in the vacuum chamber during vacuumizing are sorted to construct a sorting sequence, which is specifically represented as {vacuum chamber, gas extraction port of high vacuum pump, gas outlet port of high vacuum pump, gas extraction port of low vacuum pump, gas outlet port of low vacuum pump, exhaust port of vacuum system}, the gas pressures at the corresponding positions in the sorting sequence are taken as sequence elements, to construct the gas pressure sequence, so that the sequence order of the sorting sequence and the gas pressure sequence is consistent, wherein the corresponding sequence element of the exhaust port of the vacuum system in the sorting sequence is the standard atmospheric pressure, and the standard atmospheric pressure is a well-known knowledge and will not be described here.

[0025] It should be noted that the type and number of vacuum pumps in the vacuum system need to be determined according to the actual equipment model of the medical cyclotron, and the above examples are only used for description and explanation in the embodiment; in other embodiments, other rough vacuum pumps and ultra-high vacuum pumps and the like can also exist, and the number of various types of vacuum pumps can also be different, so the implementer can also construct other lengths of pressure sequences according to the outflow order of the gas in the vacuum chamber during vacuum pumping.

[0026] It should be noted that during the above measurement process, the simultaneity of measurement needs to be ensured, that is, the measurement time of each pressure and leakage rate should be consistent; the above measurement process is a well-known prior art to those skilled in the art, and will not be described here.

[0027] Step S2, in combination with the port connection order of the vacuum pump in the vacuum system, analyze the pressure size relationship in the pressure sequence, obtain the vacuum pump state coefficient of the vacuum system; according to the indoor air pressure and the port air pressure of the vacuum pump connected with the vacuum chamber, in combination with the vacuum pump state coefficient, obtain the corrected indoor air pressure.

[0028] Considering that under normal circumstances, the port air pressure at each port in the multi-stage vacuum pump system also has a certain progressive relationship, the air pressure of the vacuum pump port closer to the vacuum chamber is smaller, and the difference in port air pressure when the adjacent vacuum pumps are connected should be similar; therefore, in combination with the port connection order of the vacuum pump in the vacuum system, the pressure size relationship in the pressure sequence can be analyzed to evaluate and obtain the vacuum pump state coefficient of the vacuum system; the vacuum pump state coefficient reflects whether the running state of the vacuum pump is normal, and the larger the vacuum pump state coefficient, the smaller the influence on the accuracy of the subsequent vacuum degree evaluation in the vacuum chamber.

[0029] Preferably, in an embodiment of the present application, the method for obtaining the vacuum pump state coefficient comprises: Please refer to Figure 2 which shows a flow chart of a method for obtaining a vacuum pump state coefficient according to an embodiment of the present application, and specifically comprises: Step S201, according to the difference between the port air pressure at the gas suction port and the port air pressure at the gas outlet port of each vacuum pump, obtain the state confidence parameter of each vacuum pump; fuse the state confidence parameters of all vacuum pumps to obtain the first vacuum pump state parameter of the vacuum system.

[0030] Considering that in the progressive relationship, the air pressure of the vacuum pump port closer to the vacuum chamber is smaller, it is indicated that under normal circumstances, the port air pressure at the gas suction port of each vacuum pump should be smaller than the port air pressure at the gas outlet port; based on this, the state confidence parameter of each vacuum pump can be evaluated and obtained, and then the first vacuum pump state parameter in the vacuum system can be evaluated by comprehensively evaluating the state confidence parameters of all vacuum pumps.

[0031] Wherein, the state confidence parameter reflects the possibility of normal operation of each vacuum pump, and the first vacuum pump state parameter reflects the possibility of normal operation of the entire multi-stage vacuum pump system.

[0032] In a preferred embodiment of the present application, the method for obtaining the first vacuum pump state parameter comprises: calculating the pressure difference between the port pressure at the gas suction port of each vacuum pump and the port pressure at the gas outlet port; if the pressure difference is less than 0, setting the state confidence parameter of the corresponding vacuum pump as 1; if the pressure difference is greater than or equal to 0, setting the state confidence parameter of the corresponding vacuum pump as 0; and taking the product of the state confidence parameters of all vacuum pumps as the first vacuum pump state parameter of the vacuum system.

[0033] In step S202, a connection state coefficient of each port connection in the vacuum system is obtained according to the difference between adjacent pressures in the pressure sequence; and a second vacuum pump state parameter of the vacuum system is obtained by synthesizing the connection state coefficients of all port connections.

[0034] Since the port pressures of adjacent vacuum pumps should be similar when connected under normal circumstances, and the sequence order of the pressure sequence is the order of the points through which the gas flows out of the vacuum chamber during vacuum pumping, which is the same as the connection order of adjacent vacuum pumps in the multi-stage vacuum pump system, the difference between some adjacent pressures in the pressure sequence can reflect the similarity of the port pressures of each port connection, and the more similar the port pressures are, the better the connection state of the port connection is. Based on this, the connection state coefficient of each port connection can be obtained, and then the second vacuum pump state parameter in the vacuum system can be evaluated by synthesizing the connection state coefficients of all port connections.

[0035] Wherein, the connection state coefficient reflects the sealing property of each port connection, i.e. whether the connection is intact; and the second vacuum pump state parameter reflects the sealing property or the intactness of the entire vacuum system.

[0036] In a preferred embodiment of the present application, the method for obtaining the second vacuum pump state parameter comprises: At the port connection between the gas suction port of the high vacuum pump and the vacuum chamber, the port pressure of the gas suction port of the high vacuum pump and the internal pressure of the vacuum chamber are taken as set elements to construct a first port pressure set; and the ratio of the minimum value to the maximum value in the first port pressure set is taken as a first connection state coefficient. At the port connection between the gas outlet port of the high vacuum pump and the gas suction port of the low vacuum pump, the port pressure of the gas outlet port of the high vacuum pump and the port pressure of the gas suction port of the low vacuum pump are taken as set elements to construct a second port pressure set; and the ratio of the minimum value to the maximum value in the second port pressure set is taken as a second connection state coefficient. The third port pressure set is constructed by taking the port pressure of the exhaust port of the low vacuum pump and the standard atmospheric pressure at the exhaust port of the vacuum system as a set element at the port connection between the exhaust port of the low vacuum pump and the exhaust port of the vacuum system. The product of the first connection state coefficient, the second connection state coefficient, and the third connection state coefficient is taken as the second vacuum pump state parameter of the vacuum system.

[0037] As an example, in the sequence {vacuum chamber, suction port of high vacuum pump, exhaust port of high vacuum pump, suction port of low vacuum pump, exhaust port of low vacuum pump, exhaust port of vacuum system} described in step S1, the vacuum chamber and the suction port of the high vacuum pump correspond to one connection port, the exhaust port of the high vacuum pump and the suction port of the low vacuum pump correspond to one connection port, and the exhaust port of the low vacuum pump and the exhaust port of the vacuum system correspond to one connection port, totaling three connection ports. Therefore, the connection state parameters of each connection port can be evaluated according to the difference between the corresponding adjacent elements in the pressure sequence. In this example, the corresponding port pressure set at each connection port is first constructed, and then the connection state parameter at each connection port is evaluated by the ratio of the minimum value to the maximum value in the port pressure set. The closer the connection state parameter is to 1, the higher the sealing performance of the port connection, and the better the connection state. Then, the first connection state coefficient, the second connection state coefficient, and the third connection state coefficient corresponding to the three connection ports are multiplied, and the product of the three is taken as the second vacuum pump state parameter of the vacuum system. When the product of the three is large and tends to be close to 1, the second vacuum pump state parameter is larger, indicating that the sealing performance or connection state of the entire vacuum system is higher.

[0038] In step S203, the product of the first vacuum pump state parameter and the second vacuum pump state parameter is taken as the vacuum pump state coefficient.

[0039] The vacuum pump state coefficient combines the first vacuum pump state parameter reflecting whether the pressure at each port of the multi-stage vacuum pump system meets the progressive relationship under normal conditions, and the second vacuum pump state coefficient reflecting the pressure similarity at each port connection in the multi-stage vacuum pump system, and quantifies the normal operation state of the multi-stage vacuum pump system. The larger the vacuum pump state coefficient, the less likely the multi-stage vacuum pump system is to run abnormally, and the less the accuracy of the subsequent vacuum chamber vacuum degree evaluation is affected.

[0040] It should be noted that in the above embodiments, the value of the first vacuum pump state coefficient is 0 or 1, and the value of the second vacuum pump state coefficient is in the range of 0 to 1. Therefore, the value of the vacuum pump state coefficient ranges from 0 to 1.

[0041] The indoor air pressure in the vacuum chamber should be similar to the port air pressure at the pumping port of the high vacuum pump connected to the vacuum chamber, and the port air pressure can improve the reliability of the evaluation of the vacuum degree of the vacuum chamber. The indoor air pressure is measured synchronously during the vacuum pumping, and the operating state of the vacuum pump directly affects the pumping capacity and efficiency, thereby affecting the vacuum degree of the vacuum chamber. The greater the vacuum pump state coefficient, the higher the vacuum pumping efficiency, and the closer the measured indoor air pressure to the corresponding indoor air pressure in the vacuum state. When the port air pressure at the pumping port of the high vacuum pump connected to the vacuum chamber is combined, the reference significance of the port air pressure is greater. Therefore, the embodiment of the present application further obtains a corrected indoor air pressure according to the indoor air pressure, the port air pressure at the pumping port of the high vacuum pump connected to the vacuum chamber, and the vacuum pump state coefficient. By combining the port air pressure at the pumping port of the high vacuum pump connected to the vacuum chamber, the indoor air pressure is adjusted to obtain the corrected indoor air pressure, which reduces the limitations caused by relying on a single measurement result and improves the reliability of the evaluation of the vacuum degree in the vacuum chamber.

[0042] Preferably, in one embodiment of the present application, the method for obtaining the corrected indoor air pressure comprises: The constant 1 is used as the weight of the indoor air pressure, the vacuum pump state coefficient is used as the weight of the port air pressure at the pumping port of the high vacuum pump, the indoor air pressure and the port air pressure at the pumping port of the high vacuum pump are weighted and averaged, and the weighted and averaged result is used as the corrected indoor air pressure.

[0043] As an example, the calculation formula of the corrected indoor air pressure is: ; wherein, is the corrected indoor air pressure; is the indoor air pressure; is the vacuum pump state coefficient; is the port air pressure at the pumping port of the high vacuum pump.

[0044] In this example, since the value range of the vacuum pump state coefficient is 0 to 1, the constant 1 is set as the weight of the indoor air pressure, so that the weight of the indoor air pressure is greater than the weight of the port air pressure at the pumping port of the high vacuum pump, and then in the process of weighted and averaging, the measured indoor air pressure is more important than the corresponding port air pressure, and finally the weighted and averaged result is used as the corrected indoor air pressure.

[0045] Step S3: According to the deviation of the corrected indoor air pressure from the preset air pressure and the deviation of the leakage rate from the preset leakage rate, a vacuum chamber state coefficient of the vacuum system is obtained; and according to the vacuum pump state coefficient and the vacuum chamber state coefficient, a vacuum coefficient of the vacuum chamber is obtained.

[0046] After the corrected indoor air pressure is obtained, the vacuum chamber state coefficient of the vacuum system can be obtained according to the deviation of the corrected indoor air pressure from the preset air pressure and the deviation of the leakage rate from the preset leakage rate; wherein the vacuum chamber state coefficient comprehensively evaluates the possibility of the normal state of the vacuum chamber from two aspects of the corrected indoor air pressure and the leakage of the vacuum chamber; the greater the vacuum chamber state coefficient is, the higher the vacuum degree of the vacuum chamber is, and the closer to the ideal vacuum environment.

[0047] Preferably, in an embodiment of the present application, the method for obtaining the vacuum chamber state coefficient comprises: Please participate Figure 3 which shows a flow chart of a method for obtaining a vacuum chamber state coefficient according to an embodiment of the present application, and specifically comprises: In step S301, the air pressure difference between the corrected indoor air pressure and the preset air pressure is taken as the air pressure deviation; if the air pressure deviation is less than or equal to 0, the first vacuum chamber abnormal parameter is set to 0; if the air pressure deviation is greater than 0, the air pressure deviation is taken as the first vacuum chamber abnormal parameter.

[0048] As an example, the preset air pressure is set to 1.7x10 -5 Pa, which is the vacuum degree requirement standard of the medical cyclotron vacuum chamber; when the air pressure is higher than the standard, it indicates that the vacuum degree is poor; the implementer can also adjust it according to the specific model requirements of the medical cyclotron; when the air pressure deviation is less than or equal to 0, it indicates that the corrected indoor air pressure is less than or equal to the preset air pressure, and the corrected indoor air pressure is within the preset standard range; then the first vacuum chamber abnormal parameter is set to 0; on the contrary, the air pressure deviation is directly taken as the first vacuum chamber abnormal parameter; the greater the air pressure deviation is, the poorer the current vacuum state is, and the greater the first vacuum chamber abnormal parameter is.

[0049] In step S302, the leakage rate difference between the leakage rate and the preset leakage rate is taken as the leakage rate deviation; if the leakage rate deviation is less than or equal to 0, the second vacuum chamber abnormal parameter is set to 0; if the leakage rate deviation is greater than 0, the leakage rate deviation is taken as the second vacuum chamber abnormal parameter.

[0050] As an example, the preset leakage rate is set to 1x10 -10 Pa·m³ / s, which is the leakage rate requirement standard of the medical cyclotron vacuum chamber; when the leakage rate is higher than the standard, it indicates that the vacuum degree is poor; the implementer can also adjust it according to the specific model requirements of the medical cyclotron; when the leakage rate deviation is less than or equal to 0, it indicates that the leakage rate of the vacuum chamber is within the preset standard range; then the second vacuum chamber abnormal parameter is set to 0; on the contrary, the leakage rate deviation is directly taken as the second vacuum chamber abnormal parameter; the greater the leakage rate deviation is, the poorer the current vacuum state is, and the greater the second vacuum chamber abnormal parameter is.

[0051] Step S303, the sum of the first vacuum chamber abnormal parameter and the second vacuum chamber abnormal parameter is negatively correlated mapped, and the negatively correlated mapped result is taken as the vacuum chamber state coefficient.

[0052] As an example, the calculation formula of the vacuum chamber state parameter is: ; wherein, is the vacuum chamber state coefficient; is the exponential function with the natural constant e as the base; is the first vacuum chamber abnormal parameter; is the second vacuum chamber abnormal parameter.

[0053] In the present example, the sum of the first vacuum chamber abnormal parameter and the second vacuum chamber abnormal parameter is taken as x in the exponential function with the natural constant e as the base for negatively correlated mapping adjustment logic. The larger the sum is, the worse the vacuum state in the vacuum chamber is, and the lower the vacuum degree in the vacuum chamber is. When the sum is 0, it means that the current vacuum state is good, and the higher the vacuum degree is.

[0054] It is considered that the state in the vacuum chamber and the running state of the vacuum pump both have certain influence on the vacuum degree of the vacuum chamber. The better the state in the vacuum chamber and the running state of the vacuum pump are, the more ideal the vacuum environment in the vacuum chamber can be maintained, and the higher the vacuum degree of the vacuum chamber is. Therefore, the vacuum coefficient is obtained according to the vacuum pump state coefficient and the vacuum chamber state coefficient in the embodiment of the present application.

[0055] Preferably, in one embodiment of the present application, the product of the vacuum pump state coefficient and the vacuum chamber state coefficient is taken as the vacuum coefficient. The vacuum coefficient reflects the vacuum degree of the vacuum chamber from the side. The higher the vacuum coefficient is, the higher the vacuum degree of the vacuum chamber is.

[0056] Step S4, the vacuum degree of the vacuum chamber at the to-be-detected moment is evaluated according to the vacuum coefficient.

[0057] In one preferred embodiment of the present application, the method for evaluating the vacuum degree of the vacuum chamber at the to-be-detected moment according to the vacuum coefficient comprises: If the vacuum coefficient is greater than or equal to the preset threshold value, it is determined that the vacuum degree of the medical cyclotron vacuum chamber is good. If the vacuum coefficient is less than the preset threshold value, it is determined that the vacuum degree of the medical cyclotron vacuum chamber is abnormal. The preset threshold value is set to 0.55, and the implementer can also set it according to actual needs.

[0058] In another embodiment of the present application, the specific fault point in the vacuum system of the medical cyclotron can be further evaluated. The specific evaluation steps are: When the second vacuum chamber abnormal parameter is greater than 0, that is, the leakage rate is greater than the preset leakage rate, it means that the vacuum chamber is not airtight, and the vacuum chamber is marked as a fault point. When the first vacuum pump state parameter is 0, it indicates that the port pressure variation of the vacuum pump in the multi-stage vacuum pump system does not satisfy the progressive relationship, which indicates that the vacuum pump state is abnormal, and the vacuum pump is marked as a fault point; When any connection state coefficient is less than a preset threshold such as 0.85, it indicates that the sealing or connection state at the connection port is not good; when the first connection state coefficient is less than 0.85, it indicates that the sealing or connection state at the port connection between the gas extraction port of the high vacuum pump and the port of the vacuum chamber is not good; when the second connection state coefficient is less than 0.85, it indicates that the sealing or connection state at the port connection between the gas outlet port of the high vacuum pump and the initial port of the low vacuum pump is not good, or the high vacuum pump and the low vacuum pump are faulty; when the third connection state coefficient is less than 0.85, it indicates that the low vacuum pump is faulty.

[0059] The application further provides a vacuum degree detection system of a medical cyclotron vacuum chamber, which comprises a memory, a processor, and a computer program stored in the memory and capable of running on the processor, and the processor implements the steps of the vacuum degree detection method of the medical cyclotron vacuum chamber described in steps S1-S4 when executing the computer program.

[0060] To sum up, the application first acquires the leakage rate of the vacuum chamber and the gas pressure sequence of the vacuum system; then, in combination with the port connection sequence of the vacuum pump in the vacuum system, analyzes the gas pressure size relationship in the gas pressure sequence, and acquires the vacuum pump state coefficient of the vacuum system; further acquires the corrected chamber internal gas pressure; then, according to the deviation of the corrected chamber internal gas pressure from the preset gas pressure and the deviation of the leakage rate from the preset leakage rate, acquires the vacuum chamber state coefficient of the vacuum system; finally, according to the vacuum pump state coefficient and the vacuum chamber state coefficient, acquires the vacuum coefficient of the vacuum chamber, so as to evaluate the vacuum degree of the vacuum chamber. The application evaluates the running state of the vacuum pump based on the multi-stage cooperative working mode of the vacuum pump in the vacuum system, further corrects the measured chamber internal gas pressure of the vacuum chamber, then, in combination with the corrected chamber internal gas pressure and the leakage of the vacuum chamber, evaluates the vacuum chamber state; finally, comprehensively evaluates the vacuum degree of the vacuum chamber by comprehensively considering the running state of the vacuum pump and the vacuum chamber state.

[0061] It should be noted that the above-mentioned sequence of the embodiments of the application is only for description, and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multi-task processing and parallel processing are also possible or can be advantageous.

[0062] Each embodiment in the specification is described in a progressive manner, and the same or similar parts between each embodiment can be referred to each other, and each embodiment mainly describes the difference from other embodiments.

Claims

1. A method of detecting a degree of vacuum of a medical cyclotron vacuum chamber, characterized by, The method comprises: At a detection time, a leakage rate of a vacuum chamber in a vacuum system of a medical cyclotron and a gas pressure sequence of the vacuum system are acquired; the gas pressure sequence comprises a standard atmospheric pressure at an exhaust port of the vacuum system, an internal gas pressure of the vacuum chamber, and a port gas pressure at each port of each vacuum pump; A vacuum pump state coefficient of the vacuum system is acquired by analyzing a gas pressure size relationship in the gas pressure sequence in combination with a port connection sequence of the vacuum pump in the vacuum system; a corrected internal gas pressure is acquired according to the internal gas pressure and the port gas pressure of the vacuum pump connected to the vacuum chamber in combination with the vacuum pump state coefficient; A vacuum chamber state coefficient of the vacuum system is acquired according to a deviation of the corrected internal gas pressure from a preset gas pressure and a deviation of the leakage rate from a preset leakage rate; a vacuum coefficient of the vacuum chamber is acquired according to the vacuum pump state coefficient and the vacuum chamber state coefficient; The vacuum degree of the vacuum chamber at the detection time is evaluated according to the vacuum coefficient.

2. The method of claim 1, wherein the pressure of the medical cyclotron vacuum chamber is detected by a pressure gauge. The acquisition method of the gas pressure sequence comprises: The vacuum system comprises at least one high-vacuum pump and one low-vacuum pump; the gas suction port of the high-vacuum pump is connected to the vacuum chamber; the gas outlet port of the high-vacuum pump is connected to the gas suction port of the low-vacuum pump; and the gas outlet port of the low-vacuum pump is connected to the exhaust port of the vacuum system; The port gas pressures at each port of the high-vacuum pump and the low-vacuum pump, the internal gas pressure of the vacuum chamber, and the standard atmospheric pressure are respectively taken as sequence elements, and are sorted according to the gas outflow sequence in the vacuum chamber during vacuumization to construct the gas pressure sequence.

3. The method of claim 2, wherein the pressure of the medical cyclotron vacuum chamber is detected by a pressure gauge. The acquisition method of the vacuum pump state coefficient comprises: A state confidence parameter of each vacuum pump is acquired according to a difference between the port gas pressure at the gas suction port and the port gas pressure at the gas outlet port of each vacuum pump; a first vacuum pump state parameter of the vacuum system is acquired by fusing the state confidence parameters of all vacuum pumps; A connection state coefficient of each port connection in the vacuum system is acquired according to a difference between adjacent gas pressures in the gas pressure sequence; a second vacuum pump state parameter of the vacuum system is acquired by synthesizing the connection state coefficients of all port connections; The product of the first vacuum pump state parameter and the second vacuum pump state parameter is taken as the vacuum pump state coefficient.

4. The method of claim 3, wherein the pressure of the medical cyclotron vacuum chamber is detected by a pressure gauge. The acquisition method of the first vacuum pump state parameter comprises: A gas pressure difference value between the port gas pressure at the gas suction port and the port gas pressure at the gas outlet port of each vacuum pump is calculated; if the gas pressure difference value is less than 0, the state confidence parameter of the corresponding vacuum pump is set to 1; if the gas pressure difference value is greater than or equal to 0, the state confidence parameter of the corresponding vacuum pump is set to 0; The product of the state confidence parameters of all vacuum pumps is taken as the first vacuum pump state parameter of the vacuum system.

5. The method of claim 3, wherein the pressure of the medical cyclotron vacuum chamber is detected by a pressure gauge. The acquisition method of the second vacuum pump state parameter comprises: At the port connection between the gas suction port of the high-vacuum pump and the vacuum chamber, the port gas pressure of the gas suction port of the high-vacuum pump and the internal gas pressure of the vacuum chamber are taken as set elements to construct a first port gas pressure set; a first connection state coefficient is acquired by taking the ratio of the minimum value to the maximum value in the first port gas pressure set; At a port connection between an outlet port of a high vacuum pump and a suction port of a low vacuum pump, the port pressure of the outlet port of the high vacuum pump and the port pressure of the suction port of the low vacuum pump are taken as set elements to construct a second port pressure set; a ratio of a minimum value to a maximum value in the second port pressure set is taken as a second connection state coefficient; At a port connection between an outlet port of a low vacuum pump and an exhaust port of a vacuum system, the port pressure of the outlet port of the low vacuum pump and the standard atmospheric pressure at the exhaust port of the vacuum system are taken as set elements to construct a third port pressure set; a ratio of a minimum value to a maximum value in the third port pressure set is taken as a third connection state coefficient; A product of the first connection state coefficient, the second connection state coefficient and the third connection state coefficient is taken as a second vacuum pump state parameter of the vacuum system.

6. The method of claim 2, wherein the pressure of the medical cyclotron vacuum chamber is detected by a pressure gauge. The method for obtaining the corrected indoor air pressure comprises: A constant 1 is taken as a weight of the indoor air pressure, and the vacuum pump state coefficient is taken as a weight of the port pressure of the suction port of the high vacuum pump; the indoor air pressure and the port pressure of the suction port of the high vacuum pump are weighted and averaged, and a weighted and averaged result is taken as a corrected indoor air pressure of the indoor air pressure.

7. The method of claim 1, wherein the method is used for detecting a vacuum degree of a medical cyclotron vacuum chamber. The method for obtaining the vacuum chamber state coefficient comprises: A pressure difference between the corrected indoor air pressure and a preset pressure is taken as a pressure deviation; if the pressure deviation is less than or equal to 0, a first vacuum chamber abnormality parameter is set to 0; if the pressure deviation is greater than 0, the pressure deviation is taken as the first vacuum chamber abnormality parameter; A leakage rate difference between the leakage rate and a preset leakage rate is taken as a leakage rate deviation; if the leakage rate deviation is less than or equal to 0, a second vacuum chamber abnormality parameter is set to 0; if the leakage rate deviation is greater than 0, the leakage rate deviation is taken as the second vacuum chamber abnormality parameter; A sum of the first vacuum chamber abnormality parameter and the second vacuum chamber abnormality parameter is negatively correlated, and a negatively correlated result is taken as a vacuum chamber state coefficient.

8. The method of claim 1, wherein the method is used for detecting a vacuum degree of a medical cyclotron vacuum chamber. The method for obtaining the vacuum coefficient comprises: A product of the vacuum pump state coefficient and the vacuum chamber state coefficient is taken as a vacuum coefficient.

9. The method of claim 1, wherein the method is used for detecting a vacuum degree of a medical cyclotron vacuum chamber, and The method for evaluating the vacuum degree of the vacuum chamber at a detection time according to the vacuum coefficient comprises: If the vacuum coefficient is greater than or equal to a preset threshold, it is determined that the vacuum degree of the medical cyclotron vacuum chamber is good; if the vacuum coefficient is less than the preset threshold, it is determined that the vacuum degree of the medical cyclotron vacuum chamber is abnormal.

10. A system for detecting the vacuum degree of a medical cyclotron vacuum chamber, characterized by comprising: The system comprises a memory, a processor and a computer program stored in the memory and executable on the processor, and the processor implements the steps of the medical cyclotron vacuum chamber vacuum degree detection method according to any one of claims 1-9 when executing the computer program.

Images