Method for detecting vacuum degree of medical cyclotron vacuum chamber

Abstract

The present application relates to the technical field of vacuum or sealing detection, and particularly relates to a kind of vacuum degree detection method of medical cyclotron vacuum chamber.The present application first obtains the leak rate of vacuum chamber and the air pressure sequence of vacuum system;Then, in combination with the connection sequence of vacuum pump, the air pressure sequence is analyzed to obtain the state coefficient of vacuum pump of vacuum system;Further, the corrected indoor air pressure is obtained;Then, according to the deviation of the corrected indoor air pressure and the leak rate relative to the corresponding preset standard, the state coefficient of vacuum chamber of vacuum system is obtained;Finally, the vacuum coefficient of vacuum chamber is obtained, and the vacuum degree of vacuum chamber is evaluated.The present application is based on the multi-stage cooperative working mode of vacuum pump in vacuum system, evaluates the running state of vacuum pump, and then corrects the measured indoor air pressure of vacuum chamber, and then evaluates the state of vacuum chamber in combination with the corrected indoor air pressure and the leakage of vacuum chamber;Then, the vacuum degree of vacuum chamber is accurately evaluated by comprehensively considering the running state of vacuum pump and the state of vacuum chamber.

Description

Technical Field

[0001] This invention relates to the field of vacuum or sealing detection technology, specifically to a method for detecting the vacuum level of a medical cyclotron vacuum chamber. Background Technology

[0002] A medical cyclotron is a device that uses the combined action of magnetic and electric fields to accelerate charged particles and is widely used in medical radiology. In a medical cyclotron, a vacuum environment is crucial, as it helps minimize energy loss and scattering during particle acceleration, improving the output stability and accuracy of the cyclotron; therefore, vacuum testing of the vacuum chamber of a medical cyclotron is essential.

[0003] In existing technologies, vacuum gauges are typically used to detect the air pressure in the vacuum chamber of medical cyclotrons. The measured air pressure is then compared with a specified standard value to assess the vacuum level. However, the vacuum level of the vacuum chamber is mainly achieved by operating a multi-stage vacuum pump. The vacuum pump may also malfunction or leak, resulting in poor vacuuming performance. This can interfere with the assessment of the vacuum level of the vacuum chamber, potentially leading to misjudgments and low accuracy in the vacuum level detection results. Summary of the Invention

[0004] To address the technical problem of low accuracy in vacuum degree detection results for medical cyclotron vacuum chambers in existing technologies, the present invention aims to provide a method for detecting the vacuum degree of a medical cyclotron vacuum chamber. The specific technical solution adopted is as follows:

[0005] This invention proposes a method for detecting the vacuum level of a medical cyclotron vacuum chamber, the method comprising:

[0006] At the time to be detected, 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 obtained; 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.

[0007] By combining the port connection sequence of the vacuum pump in the vacuum system, the relationship between the gas pressure in the gas pressure sequence is analyzed to obtain the vacuum pump state coefficient of the vacuum system; based on the indoor gas pressure and the port gas pressure of the vacuum pump connected to the vacuum chamber, combined with the vacuum pump state coefficient, the corrected indoor gas pressure is obtained.

[0008] Based on 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 vacuum chamber state coefficient of the vacuum system is obtained; based on the vacuum pump state coefficient and the vacuum chamber state coefficient, the vacuum coefficient of the vacuum chamber is obtained.

[0009] The vacuum level of the vacuum chamber at the time of testing is evaluated based on the vacuum coefficient.

[0010] Furthermore, the method for obtaining the pressure sequence includes:

[0011] The vacuum system includes at least one high vacuum pump and one low vacuum pump, wherein the pumping port of the high vacuum pump is connected to the vacuum chamber, the exhaust port of the high vacuum pump is connected to the pumping 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.

[0012] The port pressures at each port of the high-vacuum pump and the low-vacuum pump, as well as the indoor pressure and standard atmospheric pressure of the vacuum chamber, are used as sequence elements and sorted according to the order of gas outflow from the vacuum chamber during evacuation to construct a pressure sequence.

[0013] Furthermore, the method for obtaining the vacuum pump state coefficient includes:

[0014] Based on the difference between the port pressure at the pumping port and the port pressure at the outlet port of each vacuum pump, the state confidence parameters of each vacuum pump are obtained; the state confidence parameters of all vacuum pumps are fused to obtain the first vacuum pump state parameters of the vacuum system.

[0015] Based on the difference between adjacent pressures in the pressure sequence, the connection state coefficient of each port connection in the vacuum system is obtained; by combining the connection state coefficients of all port connections, the second vacuum pump state parameter of the vacuum system is obtained.

[0016] The product of the first vacuum pump state parameter and the second vacuum pump state parameter is used as the vacuum pump state coefficient.

[0017] Furthermore, the method for obtaining the state parameters of the first vacuum pump includes:

[0018] Calculate the pressure difference between the port pressure at the pumping port and the port pressure at the outlet port of each vacuum pump; if the pressure difference is less than 0, set the state confidence parameter of the corresponding vacuum pump to 1; if the pressure difference is greater than or equal to 0, set the state confidence parameter of the corresponding vacuum pump to 0.

[0019] The product of the state confidence parameters of all vacuum pumps is taken as the first vacuum pump state parameter of the vacuum system.

[0020] Furthermore, the method for obtaining the state parameters of the second vacuum pump includes:

[0021] At the connection between the pumping port of the high vacuum pump and the port of the vacuum chamber, the port pressure of the pumping port of the high vacuum pump and the internal pressure of the vacuum chamber are used as set elements to construct a first port pressure set; the ratio of the minimum value to the maximum value in the first port pressure set is used as a first connection state coefficient.

[0022] At the port connection between the outlet port of the high vacuum pump and the pumping port of the low vacuum pump, the port pressure of the outlet port of the high vacuum pump and the port pressure of the pumping port of the low vacuum pump are used as set elements to construct a second port pressure set; the ratio of the minimum value to the maximum value in the second port pressure set is used as the second connection state coefficient.

[0023] At the port connection between the outlet port of the low vacuum pump and the exhaust port of the vacuum system, the port pressure at the outlet port of the low vacuum pump and the standard atmospheric pressure at the exhaust port of the vacuum system are used as set elements to construct a third port pressure set; the ratio of the minimum value to the maximum value in the third port pressure set is used as the third connection state coefficient.

[0024] The product of the first connection state coefficient, the second connection state coefficient, and the third connection state coefficient is used as the second vacuum pump state parameter of the vacuum system.

[0025] Furthermore, the method for obtaining the corrected indoor air pressure includes:

[0026] Using a constant 1 as the weight of the indoor air pressure, and the vacuum pump state coefficient 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 average result is used as the corrected indoor air pressure.

[0027] Furthermore, the method for obtaining the vacuum chamber state coefficient includes:

[0028] The pressure difference between the corrected chamber pressure and the preset pressure is taken as the pressure deviation; if the pressure deviation is less than or equal to 0, the 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.

[0029] The 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 abnormal parameter of the second vacuum chamber is set to 0; if the leakage rate deviation is greater than 0, the leakage rate deviation is taken as the abnormal parameter of the second vacuum chamber.

[0030] The sum of the abnormal parameters of the first vacuum chamber and the abnormal parameters of the second vacuum chamber is negatively correlated and mapped, and the result of the negative correlation mapping is used as the vacuum chamber state coefficient.

[0031] Furthermore, the method for obtaining the vacuum coefficient includes:

[0032] The product of the vacuum pump state coefficient and the vacuum chamber state coefficient is used as the vacuum coefficient.

[0033] Furthermore, the method for evaluating the vacuum level of the vacuum chamber at the time of detection based on the vacuum coefficient includes:

[0034] If the vacuum coefficient is greater than or equal to a preset threshold, the vacuum level of the medical cyclotron vacuum chamber is determined to be good; if the vacuum coefficient is less than the preset threshold, the vacuum level of the medical cyclotron vacuum chamber is determined to be abnormal.

[0035] The present invention also proposes a vacuum degree detection system for a medical cyclotron vacuum chamber. The system includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the vacuum degree detection method for a medical cyclotron vacuum chamber.

[0036] The present invention has the following beneficial effects:

[0037] This invention acquires the leakage rate of the vacuum chamber and the pressure sequence of the vacuum system within a medical cyclotron accelerator at the time of detection. This provides an analytical basis for subsequent analysis of the vacuum chamber's state and the evacuation status of the multi-stage vacuum pumps in the vacuum system. By combining the port connection sequence of the vacuum pumps in the vacuum system, the pressure relationships within the pressure sequence are analyzed to obtain a vacuum pump state coefficient reflecting the normal operation of the vacuum pumps. Based on the chamber pressure and the port pressure of the vacuum pumps connected to the vacuum chamber, combined with the vacuum pump state coefficient, a corrected chamber pressure is obtained, reducing the limitations of relying solely on a single measurement result and improving the reliability of vacuum level assessment within the vacuum chamber. Based on the deviation of the corrected chamber pressure from the preset pressure and the deviation of the leakage rate from the preset leakage rate, a vacuum chamber state coefficient reflecting the likelihood of normal operation of the vacuum chamber is obtained from both the corrected chamber pressure and leakage situation. The vacuum coefficient of the vacuum chamber is obtained based on the vacuum pump state coefficient and the vacuum chamber state coefficient. Finally, the vacuum level of the vacuum chamber at the time of detection is assessed based on the vacuum coefficient. This invention is based on the multi-stage cooperative operation mode of vacuum pumps in a vacuum system. It evaluates the operating status of the vacuum pump, corrects the measured indoor air pressure of the vacuum chamber, and then evaluates the vacuum chamber status by combining the corrected indoor air pressure and leakage situation. Finally, it comprehensively evaluates the vacuum degree of the vacuum chamber by combining the operating status of the vacuum pump and the vacuum chamber status. Attached Figure Description

[0038] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 A flowchart illustrating a method for detecting the vacuum level of a medical cyclotron vacuum chamber, as provided in one embodiment of the present invention;

[0040] Figure 2 A flowchart illustrating a method for obtaining the state coefficient of a vacuum pump according to an embodiment of the present invention;

[0041] Figure 3 This is a flowchart illustrating a method for obtaining the state coefficient of a vacuum chamber according to an embodiment of the present invention. Detailed Implementation

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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:

[0046] 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.

[0047] 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.

[0048] Considering that during the vacuuming process, the vacuum pump far from the vacuum chamber is used for initial vacuuming to create operating conditions for the vacuum pump near the vacuum chamber for precision vacuuming, as the gas in the vacuum chamber is gradually extracted, the gas pressure in the vacuum chamber will decrease and the vacuum degree will increase; the port gas pressure at each port of the sequentially connected multi-stage vacuum pump will also gradually decrease and the vacuum degree will increase, and the port gas pressure at the port closer to the vacuum chamber is lower. Therefore, there is a certain progressive relationship between the port gas pressure at each port in the multi-stage vacuum pump system. Furthermore, considering that if there is a certain leakage in the vacuum chamber, even if the multi-stage vacuum pumps continue to run, it may be difficult to maintain a stable vacuum environment in the vacuum chamber.

[0049] Therefore, in one embodiment of the present invention, the leakage rate of the vacuum chamber and the gas pressure sequence of the vacuum system in the vacuum system of the medical cyclotron are first obtained at the time to be detected, so as to facilitate the subsequent analysis of the state of the vacuum chamber and the vacuuming state of the multi-stage vacuum pump in the vacuum system, and accurately assess the vacuum degree in the vacuum chamber.

[0050] Preferably, in one embodiment of the present invention, the method for obtaining the pressure sequence includes:

[0051] The vacuum system includes at least one high vacuum pump and one low vacuum pump, wherein the pumping port of the high vacuum pump is connected to the vacuum chamber, the exhaust port of the high vacuum pump is connected to the pumping 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.

[0052] The port pressures at each port of the high-vacuum pump and the low-vacuum pump, as well as the internal pressure of the vacuum chamber and the standard atmospheric pressure, are used as sequence elements and sorted according to the order of gas outflow from the vacuum chamber during evacuation to construct a pressure sequence.

[0053] As an example, cold cathode ionization vacuum gauges are installed at the pumping and exhaust ports of each vacuum pump to measure the port pressure at each port. Then, a cold cathode ionization vacuum gauge is placed inside the vacuum chamber to collect the chamber's internal pressure. Simultaneously, a helium mass spectrometer leak detector is used to measure the leakage rate of the vacuum chamber and obtain the standard atmospheric pressure outside the vacuum system. The unit of pressure is Pa, and the unit of leakage rate is Pa·m³ / s.

[0054] Then, the points through which the gas flows out of the vacuum chamber during evacuation are sorted to construct a sorted sequence, specifically represented as {vacuum chamber, pumping port of high vacuum pump, outlet port of high vacuum pump, pumping port of low vacuum pump, outlet port of low vacuum pump, exhaust port of vacuum system}. The gas pressure at the corresponding position in the sorted sequence is used as the sequence element to construct a gas pressure sequence, so that the sequence order of the sorted sequence is consistent with the gas pressure sequence. The sequence element corresponding to the exhaust port of vacuum system in the sorted sequence is standard atmospheric pressure, which is common knowledge and will not be elaborated here.

[0055] 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. This embodiment only uses the above example as an example for description. In other embodiments, there may be other coarse vacuum pumps and ultra-high vacuum pumps, and the number of each type of vacuum pump may also be different. Therefore, the implementer can also construct other lengths of gas pressure sequence according to the gas outflow sequence in the vacuum chamber during vacuuming.

[0056] It should be noted that in the above measurement process, the simultaneity of the measurements must be ensured, that is, the measurement time of each air pressure and leakage rate should be consistent; the above measurement process is already known to those skilled in the art and will not be described in detail here.

[0057] Step S2: Combine the port connection sequence of the vacuum pump in the vacuum system to analyze the relationship between the gas pressure in the gas pressure sequence and obtain the vacuum pump state coefficient of the vacuum system; based on the indoor gas pressure and the port gas pressure of the vacuum pump connected to the vacuum chamber, and combined with the vacuum pump state coefficient, obtain the corrected indoor gas pressure.

[0058] Considering that under normal circumstances, the port pressures at each port of a multi-stage vacuum pump system also exhibit a certain progressive relationship, with the pressure at the port of the vacuum pump closer to the vacuum chamber being lower, and the port pressure differences between adjacent vacuum pumps should be similar when connected; therefore, the relationship between the pressure magnitudes in the pressure sequence can be analyzed by combining the port connection order of the vacuum pumps in the vacuum system, and the vacuum pump state coefficient of the vacuum system can be evaluated and obtained. The vacuum pump state coefficient reflects whether the vacuum pump is operating normally. The larger the vacuum pump state coefficient, the smaller the impact on the accuracy of subsequent vacuum degree assessment in the vacuum chamber.

[0059] Preferably, in one embodiment of the present invention, the method for obtaining the vacuum pump state coefficient includes:

[0060] Please see Figure 2 The diagram illustrates a flowchart of a method for obtaining the state coefficient of a vacuum pump according to an embodiment of the present invention, specifically including:

[0061] Step S201: Based on the difference between the port pressure at the pumping port and the port pressure at the outlet port of each vacuum pump, obtain the state confidence parameters of each vacuum pump; fuse the state confidence parameters of all vacuum pumps to obtain the first vacuum pump state parameters of the vacuum system.

[0062] Considering that the pressure at the vacuum pump port is lower the closer to the vacuum chamber in the progressive relationship, it means that under normal circumstances, the port pressure at the pumping port of each vacuum pump should be lower than the port pressure at the outlet port. Based on this, the state confidence parameters of each vacuum pump can be evaluated and obtained, and then the state confidence parameters of all vacuum pumps can be combined to evaluate the state parameters of the first vacuum pump in the vacuum system.

[0063] Among them, the state confidence parameter reflects the probability of each vacuum pump operating normally, while the first vacuum pump state parameter reflects the probability of the entire multi-stage vacuum pump system operating normally.

[0064] In a preferred embodiment of the present invention, the method for obtaining the state parameters of the first vacuum pump includes:

[0065] Calculate the pressure difference between the port pressure at the pumping port and the port pressure at the outlet port of each vacuum pump; if the pressure difference is less than 0, set the state confidence parameter of the corresponding vacuum pump to 1; if the pressure difference is greater than or equal to 0, set the state confidence parameter of the corresponding vacuum pump 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.

[0066] Step S202: Based on the difference between adjacent gas pressures in the gas pressure sequence, obtain the connection state coefficient of each port connection in the vacuum system; combine the connection state coefficients of all port connections to obtain the second vacuum pump state parameters of the vacuum system.

[0067] Under normal circumstances, the port pressures of adjacent vacuum pumps should be similar when connected. The sequence of the pressure sequence is based on the order of the gas flow points when the gas flows out of the vacuum chamber during evacuation, and it is the same as the connection sequence of adjacent vacuum pumps in a multi-stage vacuum pump system. Therefore, the difference between some adjacent pressures in the pressure sequence can reflect the similarity of the port pressures at each port connection. The more similar the port pressures, the better the connection status at the port connection. Based on this, the connection status coefficient of each port connection can be obtained, and then the connection status coefficients of all port connections can be combined to evaluate the status parameters of the second vacuum pump in the vacuum system.

[0068] Among them, the connection status coefficient reflects the sealing performance of each port connection, i.e., whether the connection is intact; the second vacuum pump status parameter reflects the sealing performance or connection integrity of the entire vacuum system.

[0069] In a preferred embodiment of the present invention, the method for obtaining the state parameters of the second vacuum pump includes:

[0070] At the connection between the pumping port of the high vacuum pump and the port of the vacuum chamber, the port pressure of the pumping port of the high vacuum pump and the internal pressure of the vacuum chamber are used as set elements to construct a first set of port pressures; the ratio of the minimum value to the maximum value in the first set of port pressures is used as the first connection state coefficient.

[0071] At the port connection between the outlet port of the high vacuum pump and the pumping port of the low vacuum pump, the port pressure of the outlet port of the high vacuum pump and the port pressure of the pumping port of the low vacuum pump are used as set elements to construct a second port pressure set; the ratio of the minimum value to the maximum value in the second port pressure set is used as the second connection state coefficient.

[0072] At the port connection between the outlet port of the low vacuum pump and the exhaust port of the vacuum system, the port pressure at the outlet port of the low vacuum pump and the standard atmospheric pressure at the exhaust port of the vacuum system are used as set elements to construct a third port pressure set; the ratio of the minimum value to the maximum value in the third port pressure set is used as the third connection state coefficient.

[0073] The product of the first connection state coefficient, the second connection state coefficient, and the third connection state coefficient is used as the second vacuum pump state parameter of the vacuum system.

[0074] As an example, in the sorting sequence {vacuum chamber, pumping port of high vacuum pump, outlet port of high vacuum pump, pumping port of low vacuum pump, outlet port of low vacuum pump, exhaust port of vacuum system} described in step S1, the vacuum chamber and the pumping port of high vacuum pump correspond to one connection port, the outlet port of high vacuum pump and the pumping port of low vacuum pump correspond to one connection port, and the outlet port of low vacuum pump and the exhaust port of vacuum system correspond to one connection port, for a total of 3 connection ports; therefore, the connection status parameters of each connection port can be evaluated based on the differences between corresponding adjacent elements in the pressure sequence.

[0075] In this example, a set of port pressures corresponding to each connection port is first constructed. Then, the connection status parameter at each connection port is evaluated by the ratio of the minimum to the maximum value in the set of port pressures. The closer the connection status parameter is to 1, the higher the sealing performance and the better the connection status at that port. Then, the first connection status coefficient, the second connection status coefficient, and the third connection status coefficient corresponding to the three connection ports are multiplied together, and the product of the three is used as the second vacuum pump status parameter of the vacuum system. When the product of the three is large and closer to 1, the larger the second vacuum pump status parameter is, the higher the sealing performance or connection status of the entire vacuum system is.

[0076] Step S203: The product of the first vacuum pump state parameters and the second vacuum pump state parameters is used as the vacuum pump state coefficient.

[0077] The vacuum pump state coefficient integrates the first vacuum pump state parameter, which reflects whether the gas pressure at each vacuum pump port in the multi-stage vacuum pump system conforms to the progressive relationship under normal conditions, and the second vacuum pump state coefficient, which reflects the similarity of gas pressure at the connection of each port in the multi-stage vacuum pump system. This quantifies the normal operating state of the multi-stage vacuum pump system. The larger the vacuum pump state coefficient, the lower the possibility of abnormal operation of the multi-stage vacuum pump system, and the smaller the impact on the accuracy of subsequent vacuum chamber vacuum degree assessment.

[0078] It should be noted that in the above embodiments, since 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, the value range of the vacuum pump state coefficient is 0 to 1.

[0079] Considering that the internal pressure of the vacuum chamber should be similar to the port pressure at the pumping port of the high vacuum pump connected to it, combining this port pressure can improve the reliability of the vacuum degree assessment of the vacuum chamber; also considering that the internal pressure is measured simultaneously during vacuuming, and the operating state of the vacuum pump directly affects its pumping capacity and efficiency, thus affecting the vacuum degree of the vacuum chamber; the larger the vacuum pump state coefficient, the higher the vacuuming efficiency, and the closer the measured internal pressure is to the internal pressure corresponding to the vacuum state. At the same time, when combined with the port pressure at the pumping port of the high vacuum pump, the reference significance of this port pressure is also greater.

[0080] Therefore, this embodiment of the invention further obtains a corrected indoor air pressure based on the indoor air pressure and the port air pressure of the vacuum pump connected to the vacuum chamber, combined with 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 and adjusting the indoor air pressure to obtain the corrected indoor air pressure, the limitations caused by relying solely on a single measurement result are reduced, and the reliability of the vacuum level assessment in the vacuum chamber is improved.

[0081] Preferably, in one embodiment of the present invention, the method for obtaining corrected indoor air pressure includes:

[0082] Using a constant 1 as the weight of the indoor air pressure and the vacuum pump state coefficient as the weight of the port air pressure of the high vacuum pump's pumping port, the indoor air pressure and the port air pressure of the high vacuum pump's pumping port are weighted and averaged. The weighted average result is used as the corrected indoor air pressure.

[0083] As an example, the formula for calculating corrected indoor air pressure is: ;in, To correct the indoor air pressure; Indoor air pressure; This refers to the vacuum pump state coefficient; This refers to the port pressure at the pumping port of the high vacuum pump.

[0084] In this example, since the vacuum pump state coefficient ranges from 0 to 1, a constant 1 is set as the weight of the indoor air pressure, making the weight of the indoor air pressure greater than the weight of the port air pressure of the high vacuum pump. Thus, in the weighted averaging process, the measured indoor air pressure is given more weight than the corresponding port air pressure. Finally, the weighted averaging result is used as the corrected indoor air pressure.

[0085] Step S3: Based on 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, obtain the vacuum chamber state coefficient of the vacuum system; obtain the vacuum coefficient of the vacuum chamber based on the vacuum pump state coefficient and the vacuum chamber state coefficient.

[0086] After obtaining the corrected chamber pressure, the vacuum chamber state coefficient of the vacuum system can be obtained based on the deviation of the corrected chamber pressure from the preset pressure and the deviation of the leakage rate from the preset leakage rate. The vacuum chamber state coefficient comprehensively evaluates the possibility of the vacuum chamber being in a normal state from the perspectives of the corrected chamber pressure and leakage. The larger the vacuum chamber state coefficient, the higher the vacuum level of the vacuum chamber is likely to be, and the closer it is to the ideal vacuum environment.

[0087] Preferably, in one embodiment of the present invention, the method for obtaining the vacuum chamber state coefficient includes:

[0088] Please participate Figure 3 The diagram illustrates a flowchart of a method for obtaining the state coefficient of a vacuum chamber according to an embodiment of the present invention, specifically including:

[0089] Step S301: The 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 abnormal parameter of the first vacuum chamber is set to 0; if the air pressure deviation is greater than 0, the air pressure deviation is taken as the abnormal parameter of the first vacuum chamber.

[0090] As an example, the preset air pressure is set to 1.7 × 10⁻⁶. -5 Pa is the standard vacuum level requirement for the vacuum chamber of a medical cyclotron. When the air pressure is higher than this standard, it indicates that the vacuum level is not good. 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 means that the air pressure in the correction chamber is less than or equal to the preset air pressure. If the air pressure in the correction chamber is within the preset standard range, the abnormal parameter of the first vacuum chamber is set to 0. Conversely, the air pressure deviation is directly used as the abnormal parameter of the first vacuum chamber. The larger the air pressure deviation, the worse the current vacuum state is, and the larger the abnormal parameter of the first vacuum chamber is.

[0091] Step S302: The 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 abnormal parameter of the second vacuum chamber is set to 0; if the leakage rate deviation is greater than 0, the leakage rate deviation is taken as the abnormal parameter of the second vacuum chamber.

[0092] As an example, the default leakage rate is set to 1×10. -10 Pa·m³ / s is the standard for the leakage rate requirement of the vacuum chamber of a medical cyclotron accelerator. When the leakage rate is higher than this standard, it indicates that the vacuum level is not good. The implementer can also adjust it according to the specific model requirements of the medical cyclotron accelerator. When the leakage rate deviation is less than or equal to 0, it means that the leakage rate of the vacuum chamber is within the preset standard range, and the abnormal parameter of the second vacuum chamber is set to 0. Conversely, the leakage rate deviation is directly used as the abnormal parameter of the second vacuum chamber. The larger the leakage rate deviation, the worse the current vacuum state is, and the larger the abnormal parameter of the second vacuum chamber is.

[0093] Step S303: Perform negative correlation mapping on the sum of the abnormal parameters of the first vacuum chamber and the abnormal parameters of the second vacuum chamber, and use the negative correlation mapping result as the vacuum chamber state coefficient.

[0094] As an example, the formula for calculating the state parameters of a vacuum chamber is: ;in, The vacuum chamber state coefficient; It is an exponential function with the natural constant e as the base; These are the abnormal parameters for the first vacuum chamber; These are abnormal parameters for the second vacuum chamber.

[0095] In this example, the sum of the anomaly parameters of the first and second vacuum chambers is used as an exponential function with the natural constant e as the base. The sum of x is used to adjust the negative correlation mapping logic. The larger the sum, the worse the vacuum condition in the vacuum chamber and the lower the vacuum level. When the sum is 0, it means that the current vacuum condition is good and the vacuum level is higher.

[0096] Considering that the internal condition of the vacuum chamber and the operating condition of the vacuum pump both have a certain impact on the vacuum degree of the vacuum chamber, the better the internal condition of the vacuum chamber and the better the operating condition of the vacuum pump, the more likely the ideal vacuum environment can be maintained in the vacuum chamber and the higher the vacuum degree of the vacuum chamber will be; therefore, the embodiment of the present invention will obtain the vacuum coefficient based on the vacuum pump condition coefficient and the vacuum chamber condition coefficient.

[0097] Preferably, in one embodiment of the present invention, the product of the vacuum pump state coefficient and the vacuum chamber state coefficient is used as the vacuum coefficient. The vacuum coefficient reflects the vacuum level of the vacuum chamber; the higher the vacuum coefficient, the higher the vacuum level of the vacuum chamber.

[0098] Step S4: Evaluate the vacuum level of the vacuum chamber at the time to be tested based on the vacuum coefficient.

[0099] In a preferred embodiment of the present invention, the method for evaluating the vacuum level of a vacuum chamber at the time to be detected based on the vacuum coefficient includes:

[0100] If the vacuum coefficient is greater than or equal to the preset threshold, the vacuum level of the medical cyclotron vacuum chamber is considered good; if the vacuum coefficient is less than the preset threshold, the vacuum level of the medical cyclotron vacuum chamber is considered abnormal. The preset threshold is set to 0.55, but the implementer can also set it according to actual needs.

[0101] In another embodiment of the present invention, the specific fault points in the vacuum system of the medical cyclotron can be further evaluated. The specific evaluation steps are as follows:

[0102] When the abnormal parameter of the second vacuum chamber is greater than 0, that is, when the leakage rate is greater than the preset leakage rate, it indicates that the vacuum chamber is not airtight, and the vacuum chamber is marked as the fault point.

[0103] When the status parameter of the first vacuum pump is 0, it indicates that the port pressure change of the vacuum pump in the multi-stage vacuum pump system does not meet the progressive relationship, indicating that the vacuum pump status is abnormal, and the vacuum pump is marked as a fault point.

[0104] When any connection state coefficient is less than a preset threshold, such as 0.85, it indicates that there is poor sealing or connection at the connection port; when the first connection state coefficient is less than 0.85, it indicates that the sealing or connection at the connection between the pump port of the high vacuum pump and the port of the vacuum chamber is poor; when the second connection state coefficient is less than 0.85, it indicates that the sealing or connection at the connection between the outlet port of the high vacuum pump and the initial port of the low vacuum pump is poor, or that the high vacuum pump and the low vacuum pump are malfunctioning; when the third connection state coefficient is less than 0.85, it indicates that the low vacuum pump is malfunctioning.

[0105] The present invention also proposes a vacuum degree detection system for a medical cyclotron vacuum chamber. The system includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the vacuum degree detection method for a medical cyclotron vacuum chamber described in steps S1-S4.

[0106] In summary, this invention first obtains the leakage rate of the vacuum chamber and the pressure sequence of the vacuum system; then, combining the port connection sequence of the vacuum pump in the vacuum system, it analyzes the pressure relationship in the pressure sequence to obtain the vacuum pump state coefficient; further, it obtains the corrected chamber pressure; then, based on the deviation of the corrected chamber pressure from the preset pressure and the deviation of the leakage rate from the preset leakage rate, it obtains the vacuum chamber state coefficient; finally, based on the vacuum pump state coefficient and the vacuum chamber state coefficient, it obtains the vacuum coefficient of the vacuum chamber to evaluate the vacuum degree of the vacuum chamber. This invention is based on the multi-stage cooperative operation mode of the vacuum pump in the vacuum system, evaluates the operating status of the vacuum pump, and then corrects the measured chamber pressure. Then, combining the corrected chamber pressure and leakage situation, it evaluates the vacuum chamber state; finally, by comprehensively considering the vacuum pump operating status and the vacuum chamber state, it accurately evaluates the vacuum degree of the vacuum chamber.

[0107] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0108] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

Claims

1. A method of detecting a degree of vacuum of a medical cyclotron vacuum chamber, characterized by, The method includes: At the time to be detected, 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 obtained; 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. By combining the port connection sequence of the vacuum pump in the vacuum system, the relationship between the gas pressure in the gas pressure sequence is analyzed to obtain the vacuum pump state coefficient of the vacuum system; based on the indoor gas pressure and the port gas pressure of the vacuum pump connected to the vacuum chamber, combined with the vacuum pump state coefficient, the corrected indoor gas pressure is obtained. Based on 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 vacuum chamber state coefficient of the vacuum system is obtained; based on the vacuum pump state coefficient and the vacuum chamber state coefficient, the vacuum coefficient of the vacuum chamber is obtained. The vacuum level of the vacuum chamber at the time of testing is evaluated based on the vacuum coefficient. The method for obtaining the pressure sequence includes: The vacuum system includes at least one high vacuum pump and one low vacuum pump, wherein the pumping port of the high vacuum pump is connected to the vacuum chamber, the exhaust port of the high vacuum pump is connected to the pumping 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 pressure at each port of the high vacuum pump and the low vacuum pump, as well as the indoor pressure of the vacuum chamber and the standard atmospheric pressure, are used as sequence elements and sorted according to the order of gas outflow from the vacuum chamber during evacuation to construct a pressure sequence. The method for obtaining the vacuum pump state coefficient includes: Based on the difference between the port pressure at the pumping port and the port pressure at the outlet port of each vacuum pump, the state confidence parameters of each vacuum pump are obtained; the state confidence parameters of all vacuum pumps are fused to obtain the first vacuum pump state parameters of the vacuum system. Based on the difference between adjacent pressures in the pressure sequence, the connection state coefficient of each port connection in the vacuum system is obtained; by combining the connection state coefficients of all port connections, the 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 used as the vacuum pump state coefficient. The method for obtaining the state parameters of the first vacuum pump includes: Calculate the pressure difference between the port pressure at the pumping port and the port pressure at the outlet port of each vacuum pump; if the pressure difference is less than 0, set the state confidence parameter of the corresponding vacuum pump to 1; if the pressure difference is greater than or equal to 0, set the state confidence parameter of the corresponding vacuum pump 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; The method for obtaining the state parameters of the second vacuum pump includes: At the connection between the pumping port of the high vacuum pump and the port of the vacuum chamber, the port pressure of the pumping port of the high vacuum pump and the internal pressure of the vacuum chamber are used as set elements to construct a first port pressure set; the ratio of the minimum value to the maximum value in the first port pressure set is used as a first connection state coefficient. At the port connection between the outlet port of the high vacuum pump and the pumping port of the low vacuum pump, the port pressure of the outlet port of the high vacuum pump and the port pressure of the pumping port of the low vacuum pump are used as set elements to construct a second port pressure set; the ratio of the minimum value to the maximum value in the second port pressure set is used as the second connection state coefficient. At the port connection between the outlet port of the low vacuum pump and the exhaust port of the vacuum system, the port pressure at the outlet port of the low vacuum pump and the standard atmospheric pressure at the exhaust port of the vacuum system are used as set elements to construct a third port pressure set; the ratio of the minimum value to the maximum value in the third port pressure set is used as the third connection state coefficient. The product of the first connection state coefficient, the second connection state coefficient, and the third connection state coefficient is used as the second vacuum pump state parameter of the vacuum system.

2. The method of claim 1, wherein the pressure of the medical cyclotron vacuum chamber is detected by a pressure gauge. The method for obtaining the corrected indoor air pressure includes: Using a constant 1 as the weight of the indoor air pressure, and the vacuum pump state coefficient 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 average result is used as the corrected indoor air pressure.

3. 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 obtaining the vacuum chamber state coefficient includes: The pressure difference between the corrected chamber pressure and the preset pressure is taken as the pressure deviation; if the pressure deviation is less than or equal to 0, the 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. The 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 abnormal parameter of the second vacuum chamber is set to 0; if the leakage rate deviation is greater than 0, the leakage rate deviation is taken as the abnormal parameter of the second vacuum chamber. The sum of the abnormal parameters of the first vacuum chamber and the abnormal parameters of the second vacuum chamber is negatively correlated and mapped, and the result of the negative correlation mapping is used as the vacuum chamber state coefficient.

4. 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 obtaining the vacuum coefficient includes: The product of the vacuum pump state coefficient and the vacuum chamber state coefficient is used as the vacuum coefficient.

5. The method for detecting the vacuum degree of a medical cyclotron vacuum chamber according to claim 1, characterized in that, The method for evaluating the vacuum level of the vacuum chamber at the time of detection based on the vacuum coefficient includes: If the vacuum coefficient is greater than or equal to a preset threshold, the vacuum level of the medical cyclotron vacuum chamber is determined to be good; if the vacuum coefficient is less than the preset threshold, the vacuum level of the medical cyclotron vacuum chamber is determined to be abnormal.

6. A vacuum degree detection system for a medical cyclotron vacuum chamber, characterized in that, The system includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the vacuum degree detection method for a medical cyclotron vacuum chamber as described in any one of claims 1 to 5.

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