Vacuum and high voltage radio frequency system for medical linear accelerator

Abstract

Embodiments of the present disclosure relate to a vacuum and high voltage radio frequency system for a medical linear accelerator. A radio frequency system for a radiotherapy machine includes: a first portion including a first gas at a first pressure; a second portion comprising a second gas at a second pressure, the second gas being different from the first gas; and a component between the first portion and the second portion, the component containing a first gas at a first pressure.

Description

Technical Field

[0001] The example embodiments relate to radiation support systems including klystrons. Background Technology

[0002] Current medical linear accelerators use sulfur hexafluoride (SF6) gas to prevent electric arcing within the radio frequency (RF) waveguide structure. Summary of the Invention

[0003] One or more example embodiments relate to a radio frequency (RF) system for a medical linear accelerator, configured to reduce or prevent electric arcing without using sulfur hexafluoride (SF6) gas.

[0004] One or more example embodiments provide a vacuum-based RF system for a medical linear accelerator.

[0005] One or more example embodiments provide an RF system for medical linear accelerators based on a small amount of SF6 gas and a large amount of other gases.

[0006] One or more example embodiments provide a high-pressure gas RF system for a medical linear accelerator.

[0007] At least one example embodiment provides a radio frequency system for a radiotherapy machine, the radio frequency system comprising: a first part containing a gas; a second part containing the gas; a component between the first part and the second part; and a vacuum pump configured to generate a vacuum state inside the component.

[0008] The gas can be a non-reactive gas.

[0009] The gas can be N2.

[0010] The radio frequency system may also include a regulator configured to maintain the gas pressure in the first and second sections at 1 standard atmosphere (1 atm) to 2 standard atmospheres (2 atm).

[0011] The component can be a circulator.

[0012] The component may include multiple openings, and the vacuum pump may be configured to generate a vacuum state inside the component through the multiple openings.

[0013] At least one of the first or second parts may include a waveguide, and each of the plurality of openings may be smaller than the wavelength of the radio frequency signal of the waveguide.

[0014] Multiple openings can be slits.

[0015] The vacuum pump can be attached to the component via a CF flange.

[0016] Vacuum pumps can be configured to generate a vacuum state to act as an insulator, thereby reducing electric arcing within radio frequency systems.

[0017] The radio frequency system may also include a first radio frequency window between the first part and the component, and a second radio frequency window between the second part and the component.

[0018] The radio frequency system may further include: a first portion containing a gas at a first pressure; a second portion containing the gas; and a component between the first portion and the second portion, the component containing the gas at a second pressure different from the first pressure.

[0019] The first pressure can be 1 atm to 3 atm, and the second pressure can be 3 atm to 5 atm.

[0020] The radio frequency system may also include a first radio frequency window between the first part and the component, and a second radio frequency window between the second part and the component.

[0021] The first pressure can be 3 atm to 5 atm, and the second pressure can be 5 atm to 7 atm.

[0022] The radio frequency system may also include a first radio frequency window between the first part and the component, and a second radio frequency window between the second part and the component, wherein the first radio frequency window and the second radio frequency window are blocking windows.

[0023] The radio frequency system may further include: a third portion between the first portion and the rotary joint, the third portion containing the gas at a third pressure; a fourth portion between the second portion and the radio frequency source, the fourth portion containing the gas at a third pressure; a third radio frequency window between the third portion and the first portion; and a fourth radio frequency window between the second portion and the fourth portion.

[0024] The third pressure can be 1 atm to 3 atm.

[0025] The component can be a circulator.

[0026] The gas can be a non-reactive gas.

[0027] The first pressure can be lower than the second pressure.

[0028] At least one example embodiment provides a radiofrequency system for a radiotherapy machine, the radiofrequency system comprising: a first portion containing a first gas at a first pressure; a second portion containing the first gas; and a component between the first portion and the second portion, the component containing a second gas at a second pressure, the second gas being different from the first gas.

[0029] The first pressure can be the same as the second pressure.

[0030] The second gas can be SF6, and the first gas can be a non-reactive gas different from SF6.

[0031] The first gas can be N2.

[0032] The radio frequency system may also include a first radio frequency window between the first part and the component, and a second radio frequency window between the second part and the component.

[0033] At least one example embodiment provides a radiofrequency system for a radiotherapy machine, the radiofrequency system comprising: a first portion containing a first gas at a first pressure; a second portion containing a second gas at a second pressure, the second gas being different from the first gas; and a component between the first portion and the second portion, the component containing the first gas at the first pressure.

[0034] The first pressure can be the same as the second pressure.

[0035] The first gas can be SF6, and the second gas can be a non-reactive gas different from SF6.

[0036] The second gas can be N2.

[0037] The radio frequency system may also include a rotary joint and an RF source, with the component located between the rotary joint and the RF source. Attached Figure Description

[0038] Other objects and features of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings.

[0039] However, the accompanying drawings are merely examples and illustrations, intended for illustrative purposes only, and do not limit the invention. In the drawings:

[0040] Figure 1 This is an example of a radiofrequency (RF) system for a radiotherapy machine that uses SF6 gas.

[0041] Figure 2 This is a comparative example of an RF system for a radiotherapy machine according to an example embodiment, using N2 gas and a circulator designed to process 2 atm of N2 gas.

[0042] Figure 3 This is the RF system of a radiotherapy machine according to an example embodiment.

[0043] Figure 4A This is a top view of the configuration of a vacuum pump attached to a circulator according to an example embodiment.

[0044] Figure 4B This is an example of an appendix based on an example embodiment.

[0045] Figure 5 It is an RF system for a radiotherapy machine according to an example embodiment, which uses N2 gas and a circulator designed to process 4 atm of N2 gas.

[0046] Figure 6 It is an RF system for a radiotherapy machine according to an example embodiment, which uses N2 gas and a circulator designed to process 6 atm of N2 gas.

[0047] Figure 7 This is the RF system of a radiotherapy machine according to an example embodiment.

[0048] Figure 8A and Figure 8B These are examples of side and top views of a double-ridged waveguide, respectively.

[0049] Figure 9 This is an RF system for a radiotherapy machine according to an example embodiment, which uses N2 gas in some areas and SF6 gas in others.

[0050] Figure 10 It is an appendix based on the example embodiment.

[0051] Figure 11 These are examples of Paschen curves for some example gases.

[0052] Figure 12 This is an example of a Paschen curve for a quantitative comparison of SF6 and N2 gases.

[0053] Figure 13 This is an RF system according to an example embodiment. Detailed Implementation

[0054] Various exemplary embodiments will now be described more fully with reference to the accompanying drawings, in which only a few exemplary embodiments are shown. The specific structural and functional details disclosed herein are merely illustrative of exemplary embodiments. However, exemplary embodiments may be embodied in a variety of different forms and should not be construed as limited to the illustrated embodiments. Rather, the illustrated embodiments are provided by way of example only to make this disclosure thorough and complete, and to fully convey the concepts of this disclosure to those skilled in the art. Therefore, known processes, elements, and techniques may not be described with respect to some exemplary embodiments. Unless otherwise indicated, the same reference numerals denote the same elements throughout the drawings and written description, and therefore will not be repeated. However, the invention may be embodied in many alternative forms and should not be construed as limited to the exemplary embodiments set forth herein.

[0055] This document discloses detailed illustrative embodiments. However, the specific structural and functional details disclosed herein are for the purpose of describing exemplary embodiments only. These exemplary embodiments may be embodied in various alternative forms and should not be construed as being limited to the embodiments set forth herein.

[0056] In this application, when the terms "about" and "substantially" are used in conjunction with numerical values, unless otherwise expressly defined, the numerical value intended to be associated includes a tolerance of ±10% of the stated value. Furthermore, regardless of whether a numerical value is modified with "about" or "substantially," it should be understood that these values ​​should be interpreted as including a tolerance of ±10% of the stated value. In this application, when the term "about" is used in conjunction with a numerical value of pressure, the numerical value intended to be associated includes a tolerance of ±1. For example, a waveguide configured to operate at about 2 atm can be configured to operate between 1 atm and 3 atm.

[0057] Accelerated electrons from a linear accelerator (LINAC) can then be used to generate X-rays of specific energies, for example, to treat patients. A LINAC can be a vacuum electronic device (VED) that operates using relatively high-power microwave signals. These microwave signals are generated by relatively high-power microwave sources, such as klystrons and / or magnetrons.

[0058] Microwave / radio frequency (RF) power can be conducted from the source to the LINAC via a waveguide network. When the vacuum electron microscope (VED) is in an ultra-high vacuum, the waveguide can be pressurized with a dielectric gas.

[0059] The electric field inside the hollow waveguides of RF systems such as those mentioned above can be relatively high. Dielectric gases can be used to reduce and / or prevent the possibility and / or effects of electrical breakdown in the waveguide. These high-power microwaves, traveling from the microwave source to the LINAC, may pass through various components such as circulators, flexible waveguides, rotary joints, couplers, water loads, phase bars, RF windows, etc.

[0060] Some components, such as the circulator, may generate unwanted electric arcs. To reduce or prevent electric arcs, some radiotherapy machines use sulfur hexafluoride (SF6) gas as an insulator to suppress electric arcs in the circulator.

[0061] Some radiotherapy machines reduce SF6 emissions into the atmosphere by using SF6 recovery equipment (including pumps) during machine manufacturing, maintenance, and / or repair. However, SF6 recovery processes do not address the issue of gradual SF6 leakage that can occur during normal operation. In some cases, the amount of SF6 leaked may significantly exceed the amount recovered during maintenance.

[0062] Figure 1 This is an example of an RF system for a radiotherapy machine that uses SF6 gas.

[0063] See Figure 1 The RF system 100 may include first and second RF windows 101a and 101b, first to third waveguides 102a to 102c, a rotary joint 103, a circulator 104, an RF source 110, and / or an accelerator conduit 111. Waveguides 102a to 102c may be configured to operate under an internal gas dielectric pressure of approximately 2 atm. As used herein, waveguides 102a to 102c may be referred to as waveguides, waveguide sections, or sections. As used herein, circulator 104 may be referred to as a component.

[0064] RF source 110 may be or may include an RF energy source, such as electromagnetic energy in the radio wave and / or microwave spectrum. For example, RF source 110 may be or may include at least one of a magnetron or a klystron. RF source 110 may generate electromagnetic radiation, and this electromagnetic radiation may propagate through RF system 100 to accelerator duct 111.

[0065] The RF system 100 may include a first RF window 101a coupled between the accelerator conduit 111 and the first waveguide 102a, a rotary joint 103 coupled between the first waveguide 102a and the second waveguide 102b, a circulator 104 coupled between the second waveguide 102b and the third waveguide 102c, a third waveguide 102c coupled between the circulator 104 and the second RF window 101b, and an RF source 110 coupled to the second RF window 101b. The RF window may be a pillbox-type RF window, a disc-type RF window, etc.

[0066] The circulator 104 acts as a one-way valve for microwave energy, protecting the RF source 110 by redirecting and absorbing any microwave energy reflected back from the accelerator conduit 111.

[0067] For example, at the start of beam-on operation, for the first pulse (e.g., the first few dozen pulses), a non-resonant RF pulse may be reflected backward from the accelerator duct 711. For example, the non-resonant RF pulse may be reflected backward in the first RF window 101a, the first waveguide 102a, the rotary joint 103, and / or the second waveguide 102b. The reflected portion of the pulse adds to the rest of the incoming pulse, creating an electric field that may be twice the normal intensity. Regions in the RF system 100 with doubled electric field intensity have a higher probability of experiencing arcing. The circulator 104 can reduce or prevent reflected waves from reaching and damaging the RF source 110.

[0068] The accelerator conduit 111 and the RF source 110 can be maintained under a vacuum. For example, pressurized gas may not be maintained in the accelerator conduit 111 and / or the RF source 110. For example, the vacuum state in the accelerator conduit 111 and the RF source 110 can be maintained at approximately 10. -8 The pressure below.

[0069] like Figure 1 As shown, in the RF system 100, SF6 gas at a pressure of approximately 2 atm can be maintained in waveguide 102. For example, regulator 112 can be configured to maintain the pressure in waveguide 102 and circulator 104 at approximately 2 atm. Circulator 104 can be configured to operate in which the SF6 gas at a pressure of approximately 2 atm acts as an insulator to prevent electric arcing inside circulator 104. However, SF6 is a highly damaging greenhouse gas. Therefore, a cost-effective alternative is needed to replace the use of SF6 gas to prevent electric arcing inside the circulator.

[0070] A possible alternative to using a circulator configured to operate with SF6 gas is to use a circulator configured to operate with other gases, such as nitrogen (N2).

[0071] Figure 11 These are examples of Paschen curves for some example gases.

[0072] The Paschen curve for a given gas indicates that the gas's breakdown voltage depends on pressure variations. See also Figure 11 Example Pascal plots for helium (He), neon (Ne), argon (Ar), hydrogen (H2), and nitrogen (N2) are shown. The vertical axis indicates the breakdown voltage V. B The horizontal axis indicates the combination of pressure and electrode gap distance (Torr cm). As from... Figure 11 As can be seen from the example Pascal curve shown, a high breakdown voltage V is required at high pressures. B Only then can an electric arc be generated ( Figure 11 (On the right side). As the air pressure decreases, a lower voltage V can be used. B Causes electric arc ( Figure 11 (in the middle), until the air pressure drops to almost a vacuum, in which case the vacuum acts as an insulator to prevent electric arcs ( Figure 11 (Left side).

[0073] The scale of the horizontal axis of the Paschen curve can depend on the geometry of the system containing the corresponding gas.

[0074] Figure 2 This is a comparative example of the RF system of a radiotherapy machine.

[0075] See Figure 2The RF system 200 may include first and second RF windows 201a and 201b, first to third waveguides 202a to 202c, a rotary joint 203, a circulator 204, an RF source 210, an accelerator conduit 211, and / or a regulator 212. As used herein, waveguides 202a to 202c may be referred to as waveguides, waveguide sections, or portions. As used herein, circulator 204 may be referred to as a component. Figure 2 Zhongyu Figure 1 Similar descriptions will be omitted, and the differences will be the main focus.

[0076] Unlike RF system 100, RF system 200 can be configured to operate using N2 gas instead of SF6 gas. For example, the first to third waveguides 202a to 202c and circulator 204 may include N2 at a pressure of approximately 2 atm.

[0077] Circulator 204 can be configured to operate in which N2 at a pressure of approximately 2 atm acts as an insulator, thereby preventing arcing within circulator 204. However, it should be noted that the circulator of RF system 100 (e.g., circulator 104) may not be operable by simply replacing SF6 gas with N2 gas. It is estimated that a circulator configured to operate using N2 gas, such as circulator 204, could be 1.5 to 2 times larger in volume than circulator 104, and the manufacturing cost could be significantly higher. Therefore, a more compact and cost-effective alternative is needed to replace the use of SF6 gas to prevent arcing within the circulator.

[0078] According to some example embodiments, and as referenced above Figure 11 The vacuum state can be maintained in the circulator to act as an insulator, thereby suppressing (e.g., reducing and / or preventing) electric arcs in the circulator.

[0079] Figure 3 This is the RF system of a radiotherapy machine according to an example embodiment.

[0080] See Figure 3 The RF system 300 according to an example embodiment includes first to fourth RF windows 301a to 301d, first to third waveguides 302a to 302c, a rotary joint 303, a circulator 304, a vacuum pump 305, a non-reactive gas supply source 306, a regulator 312, an RF source 310, and / or an accelerator conduit 311. As used herein, waveguides 302a to 302c may be referred to as waveguides, waveguide sections, or portions. As used herein, the circulator 304 may be referred to as a component. Figure 3 Zhongyu Figure 1 and Figure 2 Similar descriptions will be omitted, and the differences will be the main focus.

[0081] More specifically, the RF system 300 includes a first RF window 301a coupled between the accelerator duct 311 and the first waveguide 302a, a rotary joint 303 coupled between the first waveguide 302a and the second waveguide 302b, a fourth RF window 301d coupled between the second waveguide 302b and the circulator 304, a third RF window 301c coupled between the circulator 304 and the third waveguide 302c, and a second RF window 301b coupled between the third waveguide 302c and the RF source 310. These components can be coupled together in a conventional manner.

[0082] The first to fourth RF windows 201a to 301d can be, for example, medical-grade thin-walled RF windows. Over the years, medical-grade thin-walled RF windows have been proven to effectively transmit 5.5 MW RF pulses at a pressure difference of 2 atm.

[0083] and Figure 2 The comparative example shown differs; circulator 304 may be the same as or similar to conventional circulator 104, except that circulator 304 is configured to operate under vacuum. For example, a vacuum pump 305 may be attached to circulator 304 to maintain a vacuum. Furthermore, circulator 304 may include additional vacuum sealant (not shown) to maintain a vacuum.

[0084] Vacuum pump 305 includes vacuum pump 305a and vacuum pump power supply 305b. Vacuum pump 305a can be an ion pump. However, the example embodiment is not limited to this, and vacuum pump 305a can be any vacuum pump capable of maintaining a sufficient (e.g., ultra-high) vacuum state in circulator 304. For example, the vacuum pump can maintain a vacuum level below about 10 lux within circulator 304. -8 The pressure of the torrent. However, the example embodiments are not limited to this. For example, as mentioned above regarding Figure 11 The Paschen curves of the gas discussed illustrate the high insulation properties under high vacuum, but the units of the horizontal scale (e.g., pressure) depend on geometric details (e.g., the geometry of circulator 304). Therefore, the pressure maintained by vacuum pump 305 within circulator 304 can vary depending on the geometry of circulator 304. Vacuum pump power supply 305b can supply high voltage to vacuum pump 305a.

[0085] According to some example embodiments, a one-time process can be performed to generate a vacuum state inside the circulator 304. For example, a coarse pump and a turbo pump can be attached to the circulator 304 via nozzles to generate a sufficiently strong vacuum state to enable the ion pump to operate. For example, the coarse pump and / or turbo pump can be used to generate a vacuum state in the circulator 304 during manufacturing and can be removed from the circulator 304 before shipment. The vacuum pump 305a can remain attached to the circulator 304 during shipment. During shipment, the vacuum pump 305a can be battery powered, but the example embodiments are not limited to this, and the vacuum state can be maintained even without a constant power supply from the vacuum pump 305a so that the required pressure can be restored after shipment by running the vacuum pump 305a. For example, the vacuum pump 305a can be permanently attached to the circulator 304.

[0086] Figure 4A This is a top view illustrating the configuration of a vacuum pump attached to a circulator according to an example embodiment.

[0087] See Figure 4A The waveguide 304a included in the circulator 304 can have a rectangular cross-section. For example, the waveguide 304a can include a short wall 304a1 and a long wall 304a2. Attaching the pump to the short wall 304a1 would only potentially interfere with the RF current, which can be corrected by carefully selecting the aperture. The electric field along the short wall 304a1 is essentially zero, while the electric field along the long wall 304a2 reaches its maximum near the middle of the wall and is more likely to induce an arc.

[0088] like Figure 4A As shown, vacuum pump 305a may be attached to a portion of the short wall 304a1 of waveguide 304a included in circulator 304.

[0089] This portion of waveguide 304a may not be part of the circulator core, but rather a waveguide section near a port of the circulator or the RF load of the circulator. For example, circulator 304 may be a 3-port or 4-port circulator, where a port refers to an opening through which RF waves enter and / or exit circulator 304. RF waves can only enter and exit in a specific direction at each port of circulator 304. RF waves entering one port (e.g., input) must exit from a specific other port (e.g., output) based on which input is being used. In the positive direction, RF waves enter and pass through circulator 304, while reflected power is diverted to another output, where a water load absorbs and dissipates the RF in the reflected power. A load is required at a specific port to absorb the RF returning from the LINAC so that it does not return to the RF source 310. Therefore, placing a vacuum pump accessory near a port of circulator 304 or near the RF load of circulator 304 can reduce (e.g., minimize) the risk of RF waves interfering with the circulator ferrite near the core of circulator 304 during operation.

[0090] The vacuum pump 305a can be attached (e.g., coupled) to an accessory 306b on this portion of the waveguide 304a via a tube 306a. The tube 306a can be, for example, a copper tube. However, the example embodiment is not limited thereto, and the tube 306a can be any suitable material, such as low-carbon stainless steel.

[0091] Figure 4B This is an example of an appendix based on an example embodiment.

[0092] See Figure 4B Annex 306b may include multiple openings 306b1. The openings 306b1 may have a diameter smaller than the wavelength of the RF signal from the RF system 300. For example, the diameter of the opening 306b1 may be a fraction of the RF wavelength size. For instance, the diameter of the opening 306b1 may be approximately one-tenth of the RF wavelength size. Multiple openings 306b1 may be sufficient to provide adequate flow for good vacuum conduction. Therefore, the openings 306b1 can allow the vacuum pump 305a to maintain a vacuum state inside the circulator while reducing or preventing RF leakage from the circulator 304.

[0093] like Figure 4B As shown, the multiple openings 306b1 can be multiple slits. For example, the diameter d1 of the opening 306b1 in the first direction can be larger than the diameter d2 of the opening 306b1 in a second direction perpendicular to the first direction. The diameter d1 can be smaller than the wavelength of the RF signal of the RF system 300. However, since the diameter d2 is parallel to the RF wall current, it will not cause as much interference to the RF wave as d1, so the diameter d2 may not be significantly larger. For example, as... Figure 4BAs shown, the diameter d2 of the plurality of slits 306b1 can vary. The orientation of the plurality of slits 306b1 can be aligned with the direction of the wall current in that portion of the waveguide 304 (e.g., the plurality of slits 306b1 can be oriented parallel to the electric field in the waveguide). For example, the diameter d2 can be in the direction of the wall current. However, the example embodiment is not limited to this, and the plurality of openings 306b1 can be some other shape different from the slits. For example, the plurality of openings 306b1 can be a mesh of holes, where each hole has a diameter d1. A mesh of holes may be more symmetrical than slits, but has poorer gas conductivity.

[0094] The tube 306a can be attached to the vacuum pump 305a and / or accessory 306b in a manner that forms a good seal, such that the net gas inflow does not exceed the amount that the pump 305a can remove. For example, the tube 306a can be attached to the vacuum pump 305a and / or accessory 306b via a brazed CF flange. However, the example embodiment is not limited thereto, and any suitable vacuum connection device can be used.

[0095] Back Figure 3 ,and Figure 1 and Figure 2 Unlike other systems, RF system 300 may include a third RF window 301c coupled between circulator 304 and third waveguide 302c, and a fourth RF window 301d coupled between circulator 304 and second waveguide 302b. Waveguides 302a to 302c may be configured to operate at a pressure of approximately 2 atm. Therefore, regulator 312 may be configured to maintain the pressure in the waveguides at approximately 2 atm.

[0096] Non-reactive gas supply source 306 can supply non-reactive gases. For example, non-reactive gas supply source 306 can supply N2. However, the example embodiment is not limited to this, and any non-reactive gas can be used. However, as referenced above... Figure 12 The discussion may involve maintaining different nonreactive gases at pressures different from those described in the example using N2. For ease of discussion, the nonreactive gas may be referred to as N2 gas in this document. However, it should be understood that N2 may be replaced by other nonreactive gases besides SF6.

[0097] Figure 12 These are examples of Paschen curves for some example gases used to quantitatively compare SF6 and N2 gases.

[0098] See Figure 12 Example Paschen curves for N2, SF6, and air are shown. The vertical axis indicates the breakdown voltage V. B The horizontal axis indicates the combination of pressure and distance between electrodes, measured in Torr cm.

[0099] from Figure 12 As shown in the Paschen curve, in order to suppress the electric arc in the N2 gas circulator 304, the N2 gas needs to be maintained at a pressure between 2.3 and 3.5 times that of the SF6 gas pressure. For example, in order to replace the SF6 gas in the circulator 104 configured to use 2 atm of SF6 gas, the circulator 304 needs to maintain the N2 gas pressure at approximately 5 atm to 7 atm.

[0100] like Figure 3 As shown, the RF system 300 may include at least one regulator 312 attached to waveguides 302b and / or 302a, and at least one regulator 312 attached to waveguide 302c. For example, the RF system 300 may include at least one regulator on each side of the circulator 304, configured to maintain the pressure of the N2 gas between the first RF window 301a and the second RF window 301b in the RF system at about 2 atm (except for the circulator 304, which is maintained in a vacuum state). However, the example embodiment is not limited to this. For example, at least one regulator 312 may be configured to maintain the pressure of the N2 gas in the RF system 300 from the third RF window 301c to the second RF window 301b at about 2 atm, and maintain the pressure of the N2 gas from the first RF window 301a to the fourth RF window 301d at a higher pressure (e.g., about 3 atm to about 4 atm) to take into account the double-intensity electric field that may be generated by reflected RF pulses in this portion of the RF system 300.

[0101] Therefore, the RF system 300 can reduce and / or prevent arcing in the circulator 304 without using SF6. Since the RF system 300 uses an existing circulator (e.g., circulator 104) and adds vacuum, instead of using a redesigned circulator (e.g., circulator 204), the cost of the RF system 300 can be relatively low, and the increase in size of the RF system 300 can also be relatively small.

[0102] Some example embodiments provide alternative RF systems that use non-reactive gases other than SF6 and do not require maintaining a vacuum in the circulator.

[0103] Figure 5 This is the RF system of a radiotherapy machine according to an example embodiment.

[0104] See Figure 5The RF system 500 according to an example embodiment may include first to fourth RF windows 501a to 501d, first to third waveguides 502a to 502c, a rotary joint 503, a circulator 504, a non-reactive gas supply source 506, first and second regulators 312a and 312b, an RF source 510, and / or an accelerator conduit 511. As used herein, waveguides 502a to 502c may be referred to as waveguides, waveguide sections, or portions. As used herein, the circulator 504 may be referred to as a component. Figure 5 Zhongyu Figures 1-3 Similar descriptions will be omitted, and the differences will be the main focus.

[0105] More specifically, the RF system 500 includes a first RF window 501a coupled between the accelerator duct 511 and the first waveguide 502a, a rotary joint 503 coupled between the first waveguide 502a and the second waveguide 502b, a fourth RF window 501d coupled between the second waveguide 502b and the circulator 504, a third RF window 501c coupled between the circulator 504 and the third waveguide 502c, and a second RF window 501b coupled between the third waveguide 502c and the RF source 510.

[0106] As stated above, SF6 gas in a circulator designed for SF6 gas (e.g., circulator 104) cannot simply be replaced with another non-reactive gas (e.g., N2). Instead, as referenced... Figure 2 As discussed, to use N2, it may be necessary to design a circulator for N2 at approximately 2 atm to reduce or prevent arcing within the circulator. However, unlike RF system 200, RF system 500 can use a different non-reactive gas (e.g., N2) at a higher pressure (e.g., approximately 4 atm) in an existing circulator (e.g., circulator 104) to form an insulator, thereby reducing or preventing arcing within circulator 504, without designing a new circulator.

[0107] For example, with Figure 2 Unlike the comparative example described herein, RF system 500 includes a third RF window 501c coupled between circulator 504 and third waveguide 502c, and a fourth RF window 501d coupled between circulator 504 and second waveguide 502b. The third and fourth RF windows 501c and 501d may be separate windows with a small portion of waveguide and RF flanges, which are bolted to the flange of circulator 504d.

[0108] Waveguides 502a to 502c can be configured to operate at a pressure of approximately 2 atm. Therefore, a first regulator 512a can be configured to maintain the pressure in the waveguide at approximately 2 atm. For example, the RF system 500 may include at least one first regulator 512a attached to waveguides 502b and / or 502a, and at least one first regulator 512a attached to waveguide 502c. For example, the RF system 500 may include at least one regulator on each side of the circulator 504, configured to maintain the pressure of the N2 gas between the first RF window 501a and the second RF window 501b in the RF system 500 at approximately 2 atm (except for the circulator 504, which is maintained at a higher pressure). However, embodiments are not limited to this. For example, at least one regulator 512 may be configured to maintain the pressure of N2 gas in the RF system 500 from the third RF window 501c to the second RF window 501b at about 2 atm and the pressure of N2 gas from the first RF window 501a to the fourth RF window 501d at a higher pressure (e.g., about 3 atm to about 4 atm) to take into account the double-intensity electric field that may be generated by reflected RF pulses in this part of the RF system 500.

[0109] For example, circulator 504 can be configured to operate under a non-reactive gas pressure of approximately 4 atm to act as an insulator, thereby reducing and / or preventing electric arcing in circulator 504. Therefore, regulator 512b can be configured to maintain the pressure in circulator 504 at approximately 4 atm.

[0110] Figure 10 It is an appendix based on the example embodiment.

[0111] See Figure 5 and Figure 10 The second regulator 512b can be connected to an accessory 506b on the side of the waveguide 504a of the circulator 504 via a small opening 506b1 with a diameter of approximately 0.1 to 0.2 inches. This is sufficient to allow pressure in without RF leakage. Unlike accessory 306b, multiple holes or slits are not required to maintain the gas pressure in the circulator 504 because N2 can be easily filled through a single hole with a diameter of approximately 1 to 0.2 inches.

[0112] Figure 6 This is the RF system of a radiotherapy machine according to an example embodiment.

[0113] See Figure 6The RF system 600 according to an example embodiment may include first to sixth RF windows 601a to 601f, first to fifth waveguides 602a to 602e, a rotary joint 603, a circulator 604, a non-reactive gas supply source 606, first to third regulators 612a to 612c, an RF source 610, and / or an accelerator conduit 611. As used herein, waveguides 602a to 602e may be referred to as waveguides, waveguide sections, or portions. As used herein, the circulator 604 may be referred to as a component. Figure 6 Zhongyu Figures 1-3 and Figure 5 Similar descriptions will be omitted, and the differences will be the main focus.

[0114] and Figure 5 Unlike other current circulators, circulator 604 can be configured to use approximately 6 atm of a non-SF6 gas (e.g., N2) to form an insulator, thereby reducing or preventing arcing within circulator 604. (See reference...) Figure 5 Similar to the circulator 504 discussed, circulator 604 can be a current circulator (e.g., circulator 104).

[0115] The magnitude of the pressure differential that a given RF window can withstand before fracturing due to mechanical stress may be limited. For example, an RF window may last for several years under a pressure differential of 2 atm, but it may be unknown how long such an RF window could last under a pressure differential of 3 atm. To reduce the stress on the RF window, the RF system 600 employs a staged approach to ensure that the pressure differential between the ceramic side and the ceramic side of each RF window waveguide does not exceed 2 atm.

[0116] Specifically, with Figure 5 Unlike other systems, RF system 600 may include fifth and sixth RF windows 601e and 601f, and fourth and fifth waveguides 602d and 602e. The fourth and fifth waveguides may be configured to operate in a non-reactive gas at 4 atm.

[0117] Specifically, see Figure 6 The RF system 600 includes: a first RF window 601a coupled between the accelerator duct 611 and the first waveguide 602a; a rotary joint 603 coupled between the first waveguide 602a and the second waveguide 602b; a fifth RF window 601e coupled between the second waveguide 602b and the fourth waveguide 602d; a fourth RF window 601d coupled between the fourth waveguide 602d and the circulator 604; a third RF window 601c coupled between the circulator 604 and the fifth waveguide 602e; a sixth RF window 601f coupled between the fifth waveguide 602e and the third waveguide 602c; and a fourth RF window 601b coupled between the third waveguide 602c and the RF source 610.

[0118] The portions of the RF system 600 located between the first RF window 601a and the fifth RF window 601e, and between the second RF window 601b and the sixth RF window 601f, may contain a non-reactive gas at approximately 2 atm. For example, at least one first regulator 612a may be connected to at least one of the first waveguide 602a and / or the second waveguide 602b, and at least one first regulator 612a may be connected to the third waveguide 602c. The first regulator 612a may be configured to maintain a non-reactive gas at approximately 2 atm.

[0119] The portions of the RF system 600 located between the fifth RF window 601e and the fourth RF window 601d, and between the third RF window 601c and the sixth RF window 601f, may contain approximately 4 atm of non-reactive gas. For example, at least one third regulator 612c may be connected to the fourth waveguide 602d, and at least one third regulator 612c may be connected to the fifth waveguide 602e. The third regulator 612c may be configured to maintain a non-reactive gas at approximately 4 atm.

[0120] The second regulator 612b can be connected to the circulator 604. The second regulator 612b maintains the non-reactive gas in the circulator at about 6 atm to act as an insulator and thus suppress the electric arc in the circulator 604.

[0121] Figure 7 This is the RF system of a radiotherapy machine according to an example embodiment.

[0122] See Figure 7 The RF system 700 according to an example embodiment may include first to fourth RF windows 701a to 701d, first to third waveguides 702a to 702c, a rotary joint 703, a circulator 704, a non-reactive gas supply source 706, first and second regulators 712a and 712b, an RF source 710, and / or an accelerator conduit 711. As used herein, waveguides 702a to 702c may be referred to as waveguides, waveguide sections, or portions. As used herein, the circulator 704 may be referred to as a component. Figure 7 Zhongyu Figures 1-3 and Figures 5-6 Similar descriptions will be omitted, and the differences will be the main focus.

[0123] More specifically, the RF system 700 includes a first RF window 701a coupled between the accelerator conduit 711 and the first waveguide 702a, a rotary joint 703 coupled between the first waveguide 702a and the second waveguide 702b, a fourth RF window 701d coupled between the second waveguide 702b and the circulator 704, a third RF window 701c coupled between the circulator 704 and the third waveguide 702c, and a second RF window 701b coupled between the third waveguide 702c and the RF source 710.

[0124] The first regulator 712a is configured to maintain the pressure of the non-reactive gas in waveguides 702a to 702c at approximately 2 atm. The second regulator 712b is configured to maintain the pressure of the non-reactive gas in circulator 704 at approximately 6 atm to approximately 10 atm, for example, 8 atm. However, the example embodiment is not limited thereto. For example, the first regulator 712a may maintain the pressure of the non-reactive gas from the first RF window 701a to the second RF window 701b at a higher pressure (e.g., approximately 3 atm to approximately 4 atm) to take into account the double-intensity electric field that may be generated by reflected RF pulses in this part of the RF system 700.

[0125] and Figure 6 Unlike other RF windows, the third and fourth RF windows 701c and 701d do not employ a phased approach to ensure that the pressure difference from one side of the ceramic to the other does not exceed 2 atm for each RF window. Instead, they can be configured to withstand a pressure difference of more than 2 atm.

[0126] For example, the third and fourth RF windows 701c and / or 701d may include ceramic that is thicker than that of a standard thin-pane RF window. Even a slight increase in ceramic thickness can significantly enhance the strength of the RF window.

[0127] The third and / or fourth RF windows 701c and 701d may include thicker ceramics. For example, the ceramics of the third and / or fourth RF windows 701c and 701d may be approximately 20% to 50% thicker than the ceramics of standard thin-pane RF windows. Thicker ceramics can be achieved by altering the waveguide shape of the RF window near the window ceramic and / or by adding tuning elements. These tuning elements may include inductive and / or capacitive pillars and / or irises near the ceramic. For example, the ceramic thickness of the third and / or fourth RF windows 701c and 701d may be approximately 3 mm to approximately 6 mm.

[0128] Alternatively, the third and / or fourth RF windows 701c and 701d can be block windows or disk windows. These windows use rectangular ceramic and are not referred to as pillbox windows. Unlike standard pillbox windows or disk windows, block windows and disk windows do not include a circular waveguide portion surrounding the circular ceramic. Block windows and disk windows have narrower bandwidths than pillbox windows and can withstand greater voltage drops. They are called disk windows or block windows because the thickness of the ceramic is designed to be half the RF wavelength. For example, the ceramic of the third and / or fourth RF windows 701c and 701d may be approximately 3 inches for our wavelength. This special property allows RF reflections to be canceled out internally and allows all power to be transmitted unimpeded.

[0129] Alternatively, the third and / or fourth RF windows 701c and 701d can be Thomson plane windows. Thomson plane windows have a ceramic diameter smaller than the waveguide dimension. A smaller diameter means a smaller surface area exposed to high voltage and a higher yield point. To match the RF through such windows, skillful tuning is required. This includes the tuning elements mentioned above, or a double-ridged waveguide could also be used.

[0130] Figure 8A and Figure 8B These are the side view and top view of the double-ridged waveguide, respectively.

[0131] See Figure 8A and Figure 8B The dual-ridge waveguide 800 (e.g., Thomson planar window) according to an example embodiment includes a ridge 801, a wall 802, and a ceramic 803.

[0132] The double-ridged waveguide 800 includes an RF window (e.g., ceramic 803) in the middle. The diameter of the ceramic 803 is smaller than that of the waveguide 800, and therefore it can withstand higher pressures without breaking. The double-ridged transition can be used to match the RF through the ceramic 803, which would otherwise have higher reflections.

[0133] like Figure 8A As shown, due to the shape of the ridge 801, the double-ridge waveguide 800 transitions from the rectangular portion 810 to the double-ridge portion 811 and then back to the rectangular portion 810. The ridge 801 can be formed of metal. For example, the ridge 801 can be formed of the same metal as the wall 802. The ridge 801 can be molded (e.g., machined) into the wall 802 of the double-ridge waveguide 800.

[0134] Ridge 801 focuses most of the RF field through the ceramic. For example, most of the RF signal can be focused between ridges 802 and through ceramic 803 without being reflected from the metal supporting the ceramic (e.g., wall 802 and / or ridge 801).

[0135] Some example embodiments do not completely eliminate the use of SF6 by using a vacuum state in the circulator or by using other non-reactive gases, but rather use SF6 as an insulator to reduce and / or prevent arcing inside the circulator, while significantly reducing the amount of SF6 used in the RF system.

[0136] Figure 9 This is the RF system of a radiotherapy machine according to an example embodiment.

[0137] See Figure 9 The RF system 900 according to an example embodiment may include first to fourth RF windows 901a to 901d, first to third waveguides 902a to 902c, a rotary joint 903, a circulator 904, first and second non-reactive gas supply sources 906a and 906b, first and second regulators 912a and 912b, an RF source 910, and / or an accelerator conduit 911. As used herein, waveguides 902a to 902c may be referred to as waveguides, waveguide sections, or portions. As used herein, the circulator 904 may be referred to as a component. Figure 9 Zhongyu Figures 1-3 and Figures 5-7 Similar descriptions will be omitted, and the main focus will be on describing the differences.

[0138] More specifically, the RF system 900 includes a first RF window 901a coupled between the accelerator duct 911 and the first waveguide 902a, a rotary joint 903 coupled between the first waveguide 902a and the second waveguide 902b, a fourth RF window 901d coupled between the second waveguide 902b and the circulator 904, a third RF window 901c coupled between the circulator 904 and the third waveguide 902c, and a second RF window 901b coupled between the third waveguide 902c and the RF source 910.

[0139] Circulator 904 can be an existing circulator (e.g., circulator 104) configured to use SF6 at approximately 2 atm as an insulator, thereby reducing arcing within circulator 904. However, with Figure 1 Unlike other systems, the RF system 900 includes third and fourth waveguides 901c and 901d, which are respectively coupled between the circulator 904 and the second and third waveguides 902b and 902c.

[0140] In addition to circulator 904, RF system 900 can be configured to operate using a non-reactive gas (e.g., N2) at approximately 2 atm instead of SF6. For example, non-reactive gas supply source 906a can supply a non-SF6 non-reactive gas. At least one first regulator 912a can be connected to at least one of first waveguide 902a and / or second waveguide 902b, and at least one first regulator 912a can be connected to a third waveguide 902c. The first regulator 912a can be configured to maintain a non-SF6 non-reactive gas at a pressure of approximately 2 atm in RF system 900 (excluding circulator 904). However, the example embodiment is not limited thereto. For example, the first regulator 912a may be configured to maintain the pressure of N2 gas in the RF system 900 from the third RF window 901c to the second RF window 901b at about 2 atm, and maintain the pressure of N2 gas from the first RF window 901a to the fourth RF window 901d at a higher pressure (e.g., about 3 atm to about 4 atm) to take into account the double-intensity electric field that may be generated by reflected RF pulses in this part of the RF system 900.

[0141] A non-reactive gas supply source 906b can supply SF6. At least one second regulator 912b can be connected to the waveguide of the circulator 904. The regulator 912b can be configured to maintain the SF6 in the circulator 904 at a pressure of approximately 2 atm.

[0142] Therefore, the RF system 900 according to the example embodiment can reduce or prevent electric arcing inside the circulator 904, while significantly reducing the amount of SF6 used in the system. For example, the volume of SF6 used by the RF system 900 is approximately 5% (e.g., about 5-10%) of the volume of SF6 used in current RF systems (e.g., RF system 100), thus reducing greenhouse gas emissions by about 95% (e.g., about 90-95%).

[0143] Figure 13 It is an RF system according to some example embodiments.

[0144] See Figure 13 The RF system 1300 according to an example embodiment may include first to third RF windows 1301a to 1301c, first to third waveguides 1302a to 1302c, a rotary joint 1303, a circulator 1304, first and second non-reactive gas supply sources 1306a and 1306b, first and second regulators 1312a and 1312b, an RF source 1310, and / or an accelerator conduit 1311. As used herein, waveguides 1302a to 1302c may be referred to as waveguides, waveguide sections, or portions. As used herein, the circulator 1304 may be referred to as a component. Figure 13 ZhongyuFigures 1-3 , Figures 5-7 and Figure 9 Similar descriptions will be omitted, and the differences will be the main focus.

[0145] More specifically, the RF system 1300 includes a first RF window 1301a coupled between the accelerator conduit 1311 and the first waveguide 1302a, a circulator 1304 coupled between the first waveguide 1302a and the third RF window 1301c, a second waveguide 1302b coupled between the third RF window 1301c and the rotary joint 1303, and a third waveguide 1302c coupled between the rotary joint 1303 and the second RF window 1301b, wherein the second RF window 1301b is coupled between the third waveguide 1302c and the RF source 1310.

[0146] Circulator 1304 can be an existing circulator (e.g., circulator 104) configured to use SF6 gas at approximately 2 atm as an insulator, thereby reducing arcing within circulator 1304. However, with Figure 9 Unlike other devices, the position of the circulator 1304 can be moved closer to the accelerator conduit 1311. For example, as from... Figure 13 It is understood that the only waveguide section between the circulator 1304 and the accelerator duct 1311 can be the first waveguide 1302a.

[0147] Therefore, as discussed above, the circulator 1304 can reduce or prevent reflected waves from the accelerator duct 1311 from reaching any of the second waveguide 1302b, rotary joint 1303, third waveguide 1302c, or RF source 1310.

[0148] like Figure 13 As shown, circulator 1304 and first waveguide 1302a can be configured to operate using SF6 gas at approximately 2 atm. For example, a non-reactive gas supply source 1306b can supply SF6 gas, and at least one regulator 1312b can be configured to maintain the SF6 gas in first waveguide 1302a and circulator 1304 at approximately 2 atm. Figure 1 Similar to the RF system 100 shown, maintaining SF6 gas at a pressure of about 2 atm is sufficient to reduce or prevent arcing in the waveguide between the accelerator duct 1311 and the circulator 1304, where a double-intensity electric field from the reflected RF pulse may exist.

[0149] Since the circulator can reduce and / or prevent a double-strength electric field from reaching waveguides 1302b-1302c and rotary joint 1303, maintaining a non-reactive gas (e.g., N2 gas) at a pressure of approximately 2 atm, other than SF6, is sufficient to reduce or prevent arcing in this part of the RF system 1300. Therefore, the non-reactive gas supply source 1306a can supply a non-reactive gas other than SF6 (e.g., N2 gas), and at least one regulator 1312a can be configured to maintain the non-reactive gas in the second waveguide 1302b, the third waveguide 1303c, and the rotary joint 1303 at approximately 2 atm.

[0150] Therefore, according to the example embodiment, RF system 1300 can reduce or prevent electric arcing within circulator 1304 while significantly reducing the amount of SF6 used in the system. For example, the volume of SF6 used in RF system 1300 is approximately 5% (e.g., about 5-10%) of the volume of SF6 used in current RF systems (e.g., RF system 100), thus reducing greenhouse gas emissions by about 95% (e.g., about 90-95%). Although the invention has been described in detail with reference to example embodiments, the invention is not limited to the disclosed examples, and those skilled in the art can derive other variations therefrom without departing from the scope of the invention.

[0151] No element set forth in the claims is intended to be a “device plus functional element” in the sense of section 112(f) of Chapter 35 of the United States Code, unless an element is explicitly stated using the phrase “device for…” or, in the case of a method claim, explicitly stated using the phrase “operation for…” or “step for…”.

[0152] Therefore, the described exemplary embodiments can obviously be varied in many ways. Such variations should not be considered as departing from the spirit and scope of the invention, and it will be apparent to those skilled in the art that all such modifications are intended to be included within the scope of the following claims.

[0153] The terminology used herein is for describing particular embodiments only and is not intended to limit the exemplary embodiments. As used herein, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” are also intended to include the plural forms. As used herein, the terms “and / or” and “at least one of…” include any and all combinations of one or more associated listed items. It should also be understood that the terms “comprising” and / or “including” as used herein specify the presence of the stated feature, integer, step, operation, element, and / or component, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or combinations thereof. As used herein, the term “and / or” includes any and all combinations of one or more associated listed items. Expressions such as “at least one of…” when used before a list of elements modify the entire list of elements, not a single element in the list.

[0154] It should also be noted that in some alternative implementations, the functions / actions shown may differ from those shown in the diagrams. For example, two diagrams shown consecutively may actually be executed substantially simultaneously, or sometimes in reverse order, depending on the functions / actions involved.

[0155] The specific structural and functional details disclosed herein are merely illustrative of exemplary embodiments. However, the invention may be embodied in many alternative forms and should not be construed as being limited to the embodiments set forth herein.

[0156] Non-limiting illustrative examples

[0157] The following are non-limiting illustrative embodiments disclosed herein:

[0158] Illustrative Example 1. A radio frequency system for a radiotherapy machine, comprising: a first part containing gas; a second part containing gas; a component between the first part and the second part; and a vacuum pump configured to generate a vacuum state inside the component.

[0159] Illustrative Example 2. The radio frequency system according to Illustrative Example 1, wherein the gas is a non-reactive gas.

[0160] Illustrative Example 3. The radio frequency system according to any one of the foregoing illustrative examples, wherein the gas is N2.

[0161] Illustrative Example 4. The radio frequency system according to any one of the foregoing illustrative examples further includes a regulator configured to maintain the gas pressure in the first and second portions at 1 atm to 2 atm.

[0162] Illustrative Example 5. The radio frequency system according to any one of the foregoing illustrative examples, wherein the component is a circulator.

[0163] Illustrative Example 6. The radio frequency system according to any one of the foregoing illustrative examples, wherein the component includes a plurality of openings, and wherein a vacuum pump is configured to generate a vacuum state inside the component through the plurality of openings.

[0164] Illustrative Example 7. The radio frequency system according to Illustrative Example 6, wherein at least one of the first portion or the second portion includes a waveguide, and wherein each of the plurality of openings is smaller than the wavelength of the RF signal of the waveguide.

[0165] Illustrative Example 8. The radio frequency system according to Illustrative Example 6 or Illustrative Example 7, wherein the plurality of openings are slits.

[0166] Illustrative Example 9. The radio frequency system according to any one of the foregoing illustrative examples, wherein the vacuum pump is attached to the component via a CF flange.

[0167] Illustrative Example 10. The radio frequency system according to any one of the foregoing illustrative examples, wherein a vacuum pump is configured to generate a vacuum state to act as an insulator, thereby reducing electric arcing within the radio frequency system.

[0168] Illustrative Example 11. The radio frequency system according to any one of the foregoing illustrative embodiments further includes a first radio frequency window between the first portion and the component, and a second radio frequency window between the second portion and the component.

[0169] Illustrative Example 12. A radiofrequency system for a radiotherapy machine, the radiofrequency system comprising: a first portion containing a gas at a first pressure; a second portion containing the gas; and a component between the first portion and the second portion, the component containing the gas at a second pressure different from the first pressure.

[0170] Illustrative Example 13. The radio frequency system according to Illustrative Example 12, wherein the first pressure is 1 atm to 3 atm and the second pressure is 3 atm to 5 atm.

[0171] Illustrative Example 14. The radio frequency system according to Illustrative Example 12, wherein the first pressure is 3 atm to 5 atm and the second pressure is 5 atm to 7 atm.

[0172] Illustrative Example 15. The radio frequency system according to any one of Illustrative Examples 12-14 further includes: a first radio frequency window between the first portion and the component; and a second radio frequency window between the second portion and the component.

[0173] Illustrative Example 16. The radio frequency system according to any one of Illustrative Examples 12-15 further includes: a first radio frequency window between the first portion and the component; and a second radio frequency window between the second portion and the component, wherein the first radio frequency window and the second radio frequency window are blocking windows.

[0174] Illustrative Example 17. The radio frequency system according to Illustrative Example 14 further includes: a third portion between a first portion and a rotary joint, the third portion containing the gas at a third pressure; a fourth portion between a second portion and an RF source, the fourth portion containing the gas at the third pressure; a third radio frequency window between the third portion and the first portion; and a fourth radio frequency window between the second portion and the fourth portion.

[0175] Illustrative Example 18. The radio frequency system according to Illustrative Example 17, wherein the third pressure is 1 atm to 3 atm.

[0176] Illustrative Example 19. The radio frequency system according to any one of Illustrative Examples 12-18, wherein the component is a circulator.

[0177] Illustrative Example 20. The radio frequency system according to any one of Illustrative Examples 12-19, wherein the gas is a non-reactive gas.

[0178] Illustrative Example 21. The radio frequency system according to any one of Illustrative Examples 12-20, wherein the first pressure is lower than the second pressure.

[0179] Illustrative Example 22. A radiofrequency system for a radiotherapy machine, the radiofrequency system comprising: a first portion containing a first gas at a first pressure; a second portion containing the first gas; and a component between the first portion and the second portion, the component containing a second gas at a second pressure, the second gas being different from the first gas.

[0180] Illustrative Example 23. The radio frequency system according to Illustrative Example 22, wherein the first pressure and the second pressure are the same.

[0181] Illustrative Example 24. The radio frequency system according to any one of Illustrative Examples 22-23, wherein the second gas is SF6 and the first gas is a non-reactive gas different from SF6.

[0182] Illustrative Example 25. The radio frequency system according to Illustrative Example 24, wherein the first gas is N2.

[0183] Illustrative Example 26. The radio frequency system according to any one of Illustrative Examples 22-25 further includes a first radio frequency window between the first portion and the component, and a second radio frequency window between the second portion and the component.

[0184] Illustrative Example 27. A radio frequency system for a radiotherapy machine, the radio frequency system comprising: a first portion containing a first gas at a first pressure; a second portion containing a second gas at a second pressure, the second gas being different from the first gas; and a component between the first portion and the second portion, the component containing the first gas at the first pressure.

[0185] Illustrative Example 28. The radio frequency system according to Illustrative Example 27, wherein the first pressure and the second pressure are the same.

[0186] Illustrative Example 29. The radio frequency system according to any one of Illustrative Examples 27-28, wherein the first gas is SF6 and the second gas is a non-reactive gas different from SF6.

[0187] Illustrative Example 30. The radio frequency system according to Illustrative Example 29, wherein the second gas is N2.

[0188] Illustrative Example 31. The radio frequency system according to any one of Illustrative Examples 27-30 further includes a rotary connector and an RF source, wherein the component is located between the rotary connector and the RF source.

Claims

1. A radiofrequency system for a radiotherapy machine, the radiofrequency system comprising: The first part contains gas; The second part contains the gas; The component between the first part and the second part; as well as A vacuum pump configured to generate a vacuum state inside the component.

2. The radio frequency system according to claim 1, wherein the gas is a non-reactive gas.

3. The radio frequency system according to claim 1, wherein the gas is N2.

4. The radio frequency system according to claim 1, further comprising: A regulator configured to maintain the pressure of the gas in the first and second portions at 1 atm to 2 atm.

5. The radio frequency system according to claim 1, wherein the component is a circulator.

6. The radio frequency system of claim 1, wherein the component includes a plurality of openings, and The vacuum pump is configured to generate the vacuum state inside the component through the plurality of openings.

7. The radio frequency system of claim 6, wherein at least one of the first portion or the second portion comprises a waveguide, and Each of the plurality of openings is smaller than the wavelength of the radio frequency signal of the waveguide.

8. The radio frequency system of claim 6, wherein the plurality of openings are slits.

9. The radio frequency system of claim 1, wherein the vacuum pump is attached to the component via a CF flange.

10. The radio frequency system of claim 1, wherein the vacuum pump is configured to generate the vacuum state to act as an insulator, thereby reducing electric arcing within the radio frequency system.

11. The radio frequency system according to claim 1, further comprising: A first radio frequency window between the first part and the component; as well as A second radio frequency window between the second part and the component.

12. A radiofrequency system for a radiotherapy machine, the radiofrequency system comprising: The first portion contains the gas at a first pressure; The second part contains the gas; as well as A component between the first part and the second part, the component containing the gas at a second pressure, which is different from the first pressure.

13. The radio frequency system of claim 12, wherein the first pressure is 1 atm to 3 atm, and the second pressure is 3 atm to 5 atm.

14. The radio frequency system according to claim 12, further comprising: A first radio frequency window between the first part and the component; as well as A second radio frequency window between the second part and the component.

15. The radio frequency system of claim 12, wherein the first pressure is 3 atm to 5 atm, and the second pressure is 5 atm to 7 atm.

16. The radio frequency system according to claim 12, further comprising: A first radio frequency window between the first part and the component; as well as The second radio frequency window between the second part and the component The first radio frequency window and the second radio frequency window are blocking windows.

17. The radio frequency system according to claim 15, further comprising: In the third portion between the first portion and the rotary joint, the third portion contains the gas at a third pressure; In the fourth section between the second section and the radio frequency source, the fourth section contains the gas at the third pressure; The third radio frequency window between the third part and the first part; as well as The fourth radio frequency window between the second part and the fourth part.

18. The radio frequency system of claim 17, wherein the third pressure is 1 atm to 3 atm.

19. The radio frequency system of claim 12, wherein the component is a circulator.

20. The radio frequency system of claim 12, wherein the gas is a non-reactive gas.

21. The radio frequency system of claim 12, wherein the first pressure is lower than the second pressure.

22. A radiofrequency system for a radiotherapy machine, the radiofrequency system comprising: A first portion comprising a first gas at a first pressure; The second part contains the first gas; as well as The component between the first part and the second part contains a second gas at a second pressure, the second gas being different from the first gas.

23. The radio frequency system of claim 22, wherein the first pressure is the same as the second pressure.

24. The radio frequency system of claim 22, wherein the second gas is SF6, and the first gas is a non-reactive gas different from SF6.

25. The radio frequency system of claim 24, wherein the first gas is N2.

26. The radio frequency system according to claim 22, further comprising: A first radio frequency window between the first part and the component; as well as A second radio frequency window between the second part and the component.

27. A radiofrequency system for a radiotherapy machine, the radiofrequency system comprising: A first portion comprising a first gas at a first pressure; A second portion comprising a second gas at a second pressure, the second gas being different from the first gas; as well as The component between the first part and the second part contains the first gas at the first pressure.

28. The radio frequency system of claim 27, wherein the first pressure is the same as the second pressure.

29. The radio frequency system of claim 27, wherein the first gas is SF6, and the second gas is a non-reactive gas different from SF6.

30. The radio frequency system of claim 29, wherein the second gas is N2.

31. The radio frequency system according to claim 27, further comprising: Rotary joint; as well as RF source The component is located between the rotary joint and the RF source.

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