Method for deflecting gas jet in pressurized system

Abstract

To provide articles of manufacture, systems, and methods employing a gas-deflector plate in low to ultra-high vacuum systems that use differential pumping.SOLUTION: In certain embodiments, a gas-deflector plate is configured to be positioned between higher and lower pressure regions in a pressurized system. The gas-deflector plate has a channel extending through the gas-deflector plate, the channel being shaped and / or angled such that jetting gas moving through the channel enters the lower pressure region at an angle offset from a vertical axis of the gas-deflector plate and / or the channel. In other embodiments, a jet-deflector component is employed such that the jetting gas strikes such a jet-deflector component and is re-directed in another direction.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001] This application claims priority to U.S. Provisional Application No. 62 / 876,116, filed July 19, 2019, which is incorporated by reference in its entirety.

[0002] Provided herein are products, systems and methods employing a gas-deflector plate in low to ultra-high vacuum systems using differential pumping (e.g., gas-target particle accelerators, mass spectrometers, electron beam welding and windowless delivery ports). In certain embodiments, the gas-deflector plate is configured to be disposed between a higher pressure region and a lower pressure region in a pressurized system, with the channel through the gas-deflector plate shaped and / or angled such that a jetting gas moving through the channel enters the lower pressure region at an angle offset from the normal axis of the channel and / or the gas-deflector plate. In other embodiments, such a jet-deflector component is employed such that the jetting gas hits the jet-deflector component and is redirected in another direction. [Background technology]

[0003] Particle accelerator target designs can take the form of solids, liquids, or gas / plasmas. High pressure gas from the target will naturally flow towards the lower pressure parts of the accelerator system where high vacuum is required. Vacuum windows can be used to separate the target material from the high vacuum environment of the beamline while still allowing high energy particles to pass through. For accelerators operated continuously at high fluxes, the thermal stresses on the windows can be difficult to manage, making such an approach ineffective.

[0004] An alternative approach is to focus the beam through a narrow diameter aperture into the target chamber. To address this natural transport of gases escaping the target, a differential pumping system is employed, consisting of multiple pumping stages separated by additional coaxial apertures - up to 10 in a beamline. 9 Pressure ratios exceeding 1000 MPa are possible. In this approach, the high pressure target gas expanding through the target aperture will accelerate during its passage into the adjacent differentially pumped stage. In the case of a linear beamline where all pumping apertures are coaxial, this phenomenon can result in a significant portion of the blast gas condensing and crossing the adjacent pumping stage. As a result, higher pressures will propagate further up the course of the beamline. These higher pressures can then impede beam transport by increasing charge exchange, scattering, and / or reducing the focusing ability and overall effectiveness of the accelerator. Summary of the Invention

[0005] Provided herein are products, systems and methods employing a gas-deflector plate that may be combined with an asymmetric nozzle in low to ultra-high vacuum systems using differential pumping (e.g., gas-target particle accelerators, mass spectrometers, electron beam welding and windowless delivery ports). In certain embodiments, the gas-deflector plate is configured to be disposed between a higher pressure region and a lower pressure region in a pressurized system, with the channel through the gas-deflector plate shaped and / or angled such that a jetting gas moving through the channel enters the lower pressure region at an angle offset from the normal axis of the channel and / or the gas-deflector plate. In other embodiments, such a jet-deflector component is employed such that the jetting gas hits the jet-deflector component and is redirected in another direction.

[0006] In some embodiments, an article of manufacture includes a gas deflection plate having a top surface, a bottom surface, and a channel extending therethrough, the gas deflection plate having i) a vertical axis and a horizontal axis extending therethrough that are parallel to the top surface and the bottom surface, and ii) a vertical axis that is perpendicular to the vertical axis and the horizontal axis, the gas deflection plate being configured to be disposed between a region of higher pressure and a region of lower pressure in a pressurized system (e.g., as described in U.S. Pat. No. 8,837,662, which is incorporated herein by reference in its entirety) such that the top surface faces a region of lower pressure and the bottom surface faces a region of higher pressure, the channel having i) a top opening in the top surface of the gas deflection plate, and ii) a bottom opening in the bottom surface of the gas deflection plate. and a channel having a shape and / or angle such that a jet of gas traveling through the channel from the region of higher pressure to the region of lower pressure enters the region of lower pressure at an angle offset from the vertical axis.

[0007] In certain embodiments, a system is provided herein that includes: a) any of the gas deflector plates described herein; and b) a jet deflector component having a first surface, the jet deflector component being configured to be positioned in a lower pressure region such that the jet of gas entering the lower pressure region strikes the first surface and is redirected in a different direction. In certain embodiments, the first surface has a shape selected from the group of flat, concave, convex, and textured shapes. In other embodiments, the jet deflector component further includes a first mounting component (e.g., screws, rods, holes, nuts, etc.), and the gas deflector plate further includes a second mounting component (e.g., screws, rods, holes, nuts, etc.), and the first and second mounting components allow the jet deflector component to be attached to the gas deflector plate (e.g., with bolts and openings for bolts).

[0008] In some embodiments, a system is provided that includes: a) a pressurization subsystem that includes i) a region of higher pressure and ii) a region of lower pressure; and b) a gas deflector plate that includes a top surface, a bottom surface, and a channel extending through the gas deflector plate, the gas deflector plate having i) a longitudinal axis and a lateral axis that extend through the gas deflector plate that are parallel to the top surface and the bottom surface, and ii) a vertical axis that is perpendicular to the longitudinal axis and the lateral axis, the gas deflector plate having a top surface that faces the lower pressure region. Provided herein is a system having a channel disposed between the higher pressure region and the lower pressure region such that the channel faces the higher pressure region and the bottom faces the higher pressure region, the channel including i) a top opening in the top surface of the gas deflector plate and ii) a bottom opening in the bottom surface of the gas deflector plate, the channel having a shape and / or angle such that a jet of gas traveling through the channel from the higher pressure region to the lower pressure region enters the lower pressure region at an angle offset from the vertical axis. In certain embodiments, the system further comprises c) a jet deflector component having a first surface, the jet deflector component being disposed within the lower pressure region such that the jet of gas entering the lower pressure region strikes the first surface and is redirected in a different direction.

[0009] In another embodiment, a system includes: a) a pressurizable subsystem including: i) a first region; and ii) a second region; and b) a gas deflector plate having a top surface, a bottom surface, and a channel extending through the gas deflector plate, the gas deflector plate having i) a longitudinal axis and a lateral axis extending through the gas deflector plate that are parallel to the top surface and the bottom surface, and ii) a vertical axis that is perpendicular to the longitudinal axis and the lateral axis, the gas deflector plate having a top surface facing the front surface. Provided herein is a system having a channel disposed between the first and second regions such that the channel faces the second region and the bottom surface faces the first region, the channel including i) an upper opening in the upper surface of the gas deflection plate and ii) a bottom opening in the bottom surface of the gas deflection plate, the channel having a shape and / or angle such that a jet of gas traveling through the channel from the first region to the second region enters the second region at an angle offset from the vertical axis.

[0010] In another embodiment, the method includes the steps of: a) disposing a gas deflection plate between a first region and a second region of a pressurizable system, wherein the gas deflection plate comprises a top surface, a bottom surface, and a channel extending through the gas deflection plate, the gas deflection plate having i) a longitudinal axis and a lateral axis extending through the gas deflection plate that are parallel to the top surface and the bottom surface, and ii) a vertical axis that is perpendicular to the longitudinal axis and the lateral axis, the gas deflection plate being disposed between the first region and the second region such that the top surface faces the second region and the bottom surface faces the first region. Provided herein is a method comprising one or more of: i) a channel including: i) a top opening in the top surface of the gas deflection plate; and ii) a bottom opening in the bottom surface of the gas deflection plate; and b) actuating the pressurizable subsystem such that the pressurizable system is pressurized and the first region is at a higher pressure than the second region, whereby a jet of gas travels through the channel from the first region to the second region and enters the second region at an angle offset from the vertical axis.

[0011] In certain embodiments, there are no physical components blocking the jet of gas from the channel into the area of ​​low pressure. In certain embodiments, the angle of the jet of gas is offset from the vertical axis by at least 5 degrees or at least 10 degrees (e.g., at least 5 degrees...10 degrees...15 degrees...25 degrees...35 degrees...45 degrees...55 degrees...65 degrees...75 degrees...or 85 degrees). In some embodiments, the angle of the channel is offset from the vertical axis by at least 5 degrees or at least 10 degrees (e.g., at least 5 degrees...10 degrees...15 degrees...25 degrees...35 degrees...45 degrees...55 degrees...65 degrees...75 degrees...or 85 degrees). In other embodiments, the top opening comprises an asymmetric opening. In a further embodiment, the asymmetric opening is formed from first and second portions of the channel, the first portion being on an opposite side of the asymmetric opening from the second portion, and the second portion being at a greater angular offset from the vertical axis than the first portion.

[0012] In some embodiments, the pressurization system includes a differential pumping system. In certain embodiments, the pressurization system includes a particle accelerator system including i) an ion source, ii) an ion accelerator, iii) a differential pumping system, and iv) a target chamber. In some embodiments, the particle accelerator system includes some or all of the components of the system found in U.S. Pat. No. 8,837,662, which is incorporated herein by reference in its entirety. In further embodiments, the gas deflection plate is configured to be disposed between the target chamber and the differential pumping system. In other embodiments, the target chamber includes the higher pressure region and the differential pumping system includes the lower pressure region. In further embodiments, the pressurization system includes a mass spectrometer. In other embodiments, the mass spectrometer includes i) a sample chamber, ii) a differential pressure stage, and iii) an ionization chamber. In some embodiments, the gas deflection plate is configured to be disposed between the sample chamber and the differential pumping stage. In other embodiments, the sample chamber includes the higher pressure region and the differential pressure stage includes the lower pressure region. In certain embodiments, the channel has a diameter along most or all of its length of about 2.5-9.0 mm (e.g., 3.5 mm...4.5 mm...5.0 mm...5.5 mm...6.5 mm...7.9 mm...9.0 mm). In certain embodiments, the length of the channel is about 4-6 times the diameter of the channel. In certain embodiments, the length of the channel is about 15-35 mm (e.g., 15 mm...20 mm...25 mm...or 35 mm). In other embodiments, the top opening has a diameter of about twice the diameter of the channel, or about 6-18 mm (e.g., 7 mm...10 mm...15 mm...17 mm). In further embodiments, the gas deflector plate has a thickness between the top surface and the bottom surface of about 13-40 mm (e.g., 13 mm...25 mm...34 mm...or 40 mm). In other embodiments, the gas deflector has a circular or nearly circular shape, or a square or nearly square shape.In other embodiments, most or all of the gas deflector plate is made of a metal, hi further embodiments, the metal is selected from the group consisting of copper, tungsten, and stainless steel.

[0013] In some embodiments, the gas deflector includes one or more openings that allow attachment to the higher pressure area and / or the lower pressure area.

[0014] In certain embodiments, the jet deflector component is attached to the top surface of the gas deflector plate. In other embodiments, the pressurization subsystem is selected from the group consisting of a gas-target particle accelerator, a mass spectrometer, and a windowless outlet. In other embodiments, the higher pressure region comprises a target chamber of a particle accelerator and the lower pressure region comprises a portion of a differential pumping system. In certain embodiments, the gas deflector plate is constructed of a heat resistant material. [Brief description of the drawings]

[0015] [Figure 1A] A gas-target particle accelerator is shown having a pair of gas deflector plates (30) between components having different pressures. [Figure 1B] A plate (50) is shown with uniform channels (1) that go straight through the plate and do not reduce pressure. [Diagram 2] An exemplary schematic diagram of a three-stage differential pumping configuration with uniform and straight channels (1) is shown. [Figure 3A] An exemplary gas deflector (30) is shown having channels (70) with asymmetric openings (7) that deflect a gas jet (arrow; 8) away from the normal axis of the gas deflector. [Figure 3B] 3A with dashed lines indicating the vertical (40) and horizontal (41) axes. [Figure 4]An exemplary schematic diagram of a three-stage differential pumping configuration with asymmetric openings (7) that deflect the blast gas (arrows; 8) downwards is shown. In certain embodiments, this asymmetry in the openings is differently positioned such that the blast gas is directed upward, left or right. [Figure 5A] An exemplary gas deflector plate is shown with asymmetric openings (7) that deflect a gas jet (arrow; 8) away from the vertical axis. When the gas jet hits the jet deflector (10), it is deflected in another direction (arrow; 12). [Figure 5B] 5A with a dotted line indicating the vertical axis (42). [Figure 6] An exemplary schematic diagram of a three-stage differential pumping configuration with asymmetric openings and a jet deflector (10) that moves the jet gas in different directions (arrows; 12) is shown. [Figure 7] Figure 1 shows the use of a channel (70) with an asymmetric aperture (7) for gas jet deflection in a particle accelerator application, with the particle beam shown as a dotted line (14). [Figure 8] 1 illustrates the use of a channel with an asymmetric aperture for gas jet deflection in a mass spectrometer. [Figure 9] An exemplary jet deflector device (10) is shown bolted to a gas deflector plate (30) using bolts (95). [Figure 10] An exemplary gas deflector (30) is shown that is composed of two parts: an outer housing and an inner replaceable "puck." In certain embodiments, these parts are held in place by other components such that leak paths between high and low pressure areas are minimized. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Provided herein are products, systems and methods employing a gas-deflector plate in low to ultra-high vacuum systems (e.g., gas-target particle accelerators, mass spectrometers and windowless delivery ports) using differential pumping. In certain embodiments, the gas-deflector plate is configured to be disposed between a higher pressure region and a lower pressure region in a pressurized system, with the channel through the gas-deflector plate shaped and / or angled such that a jetting gas moving through the channel from the higher pressure region to the lower pressure region enters the lower pressure region at an angle offset from the normal axis of the gas-deflector plate. In other embodiments, such a jet-deflector component is employed such that the jetting gas hits the jet-deflector component and is redirected in another direction.

[0017] In certain embodiments, the present disclosure provides gas deflection techniques for deflecting supersonic jets in differential pumping applications. In some embodiments, the deflection device is a gas deflector plate having a channel with an asymmetric aperture. When high pressure gas expands through the channel and the asymmetric aperture, the resulting gas jet (e.g., a supersonic gas jet) acquires an off-axis velocity component in the asymmetric direction. In certain embodiments, the shape and / or angle of the channel redirects the gas jet in a differential pumping system, reducing mass transport to lower pressure sections while reducing the pumping requirements to maintain a given stage pressure. In certain embodiments, the deflection of the gas jet is further improved by the addition of a jet deflector component located in the asymmetric direction of the aperture.

[0018] In some embodiments, systems, devices, and methods are provided herein that provide jet deflection techniques to mitigate the effects of supersonic and subsonic gas jets in staged differential pressure applications. In certain embodiments, angled and / or shaped (e.g., with asymmetric openings) gas deflector plates are provided herein in combination with jet deflector components that direct the jet gas off-axis of the plate. In certain embodiments, such gas deflector plates reduce mass transport between multiple differential pumping stages, thereby reducing pumping requirements and / or allowing lower base pressure for a given configuration.

[0019] In certain embodiments, systems, devices, and methods are provided herein that improve efficiency in differentially pumped systems. That is, the use of the systems, devices, and methods herein allows, for example, a larger pressure differential, all things being equal, or allows the same pressure differential to be achieved using smaller and / or fewer pumps, or allows a larger opening to exist between high pressure and low pressure regions. In certain embodiments, the systems, devices, and methods herein allow a larger opening diameter to be used for a given pumping configuration.

[0020] Below, a description of certain exemplary embodiments shown in the drawings is provided. It should be understood that the application of the present invention is not limited to such exemplary embodiments. Furthermore, in certain embodiments, the gas deflector and jet deflector components described below are used in accelerator systems such as those described in U.S. Patent No. 8,837,662. U.S. Patent No. 8,837,662 is incorporated herein by reference in its entirety.

[0021] 1A shows a gas-target particle accelerator (25) with a pair of gas deflection plates (30) between components with different pressures. An ion source (26) is connected to an accelerator (27) which is connected to two differential pumping systems with two stages (28). Each stage is connected to a vacuum pump (29). A target chamber (32) has an ion confinement magnet (31) around it and is connected to the differential pumping system with the gas deflection plates (30) in between. The horizontal axis (40) of the gas deflection plates is shown by a dotted line.

[0022] FIG. 1B shows a plate with a uniform channel (1) that runs straight through the plate (50). FIG. 2 shows the use of such a uniform channel (1) located between a higher pressure stage (2) and a lower pressure stage (3). As a result of using a uniform channel (1), the gas jet (4) from the higher pressure stage to the lower pressure stage goes straight into the lower pressure stage (3) instead of being offset. When an opening 1 is located between two stages of different pressure, where stage (2) is at a higher pressure than stage (3), the pressure difference between the two stages will result in a gas flow between the stages, tending to equalize the pressure in the two stages. A pump can be employed to counteract this mass flow. The pump will return gas discharged into the lower pressure stage back into the higher pressure stage, thus maintaining the pressure difference. Ultimately, the pressure difference that can be maintained between the connected regions will depend on the exhaust capacity of each region and the size of the opening between the two regions. A commonly observed phenomenon that reduces the efficiency of a coaxial differential pumping system is the formation of gas jets between regions. If the pressure is sufficiently different between any two stages, gas emerging from the higher pressure region will form a jet as it enters the lower pressure region. The jet is a continuous, coherent, directional flow of gas that can traverse a given pressure region and emerge largely intact (unaffected) into the next pumping stage. The jet effectively "bypasses" a given pumping stage, thereby significantly reducing the efficiency of the differential pumping system.

[0023] For systems with three or more stages, a significant portion of the jet may traverse the first differentially pumped stage (3), reducing the efficiency of this stage while increasing the upstream pressure and exhaust demands in stages (5) and (6).

[0024] The problem of such gas jet bypass is addressed by the devices, systems and methods described herein. The function of these devices, systems and methods is to deflect the gas jet (jet of gas) off-axis and reduce or destroy its cohesiveness so that the pump at any given stage can act on the gas. For example, the gas deflector plates herein with angled or shaped channels (e.g., with asymmetric openings) result in gas jets with velocity components off-axis of the opening axis and / or the gas deflector plate. This velocity offset is, for example, in the asymmetric direction shown by arrow (8) in FIG. 3. This deflection limits the gas that is injected directly into the next differential pumping stage. In some embodiments, multiple configurations of this asymmetric opening are placed in series between pumping stages to increase this effect (see FIG. 1A).

[0025] Figure 3A shows an exemplary gas deflector plate (30) with a channel (70) with asymmetric openings (7) that deflect the jet of gas (arrow; 8) away from the vertical axis (beam axis) of the gas deflector plate. Figure 3B shows the exemplary gas deflector plate (30) of Figure 3A with dotted lines indicating the vertical axis (40) and horizontal axis (41). The vertical and horizontal axes are perpendicular to the vertical axis (beam axis).

[0026] Figure 4 shows an exemplary schematic diagram of a three-stage differential pumping configuration with asymmetric openings (7) that deflect the jet of gas (arrows; 8) downward away from the vertical axis (beam axis). Boxes (3), (5) and (6) represent the differential pumping stages. Stage (2) is a higher pressure stage than stages (3), (5) and (6).

[0027] Figure 5A shows an exemplary gas deflector plate with a channel (70) with asymmetric openings (7) that deflect the gas jet (arrow; 8) away from the vertical axis (beam axis). When the gas jet hits the jet deflector component (10), the gas jet is deflected in another direction (arrow; 12). Figure 5B shows the exemplary gas deflector plate (30) of Figure 5A with a dotted line indicating the vertical axis (42) (aka "beam axis").

[0028] FIG. 6 shows an example schematic of a three-stage differential pumping configuration with an asymmetric aperture and a jet deflector component (10) that moves the gas jet in different directions (arrows; 12) that are offset from the vertical axis (beam axis). Boxes (3), (5) and (6) show the differential pumping stages. Stage (2) is a higher pressure stage than stages (3), (5) and (6). The addition of the jet deflector component provides additional deflection of the gas jet as indicated by arrows (12).

[0029] FIG. 7 shows the use of a channel (70) with asymmetric openings for gas jet deflection in a particle accelerator application. A particle beam is shown as a dotted line (14). With a particle accelerator as shown in this figure, particles are accelerated into a high pressure gas (or plasma) target (13) long enough to decelerate the particle beam, shown by the arrow (14). The pressure in the target is higher than the differential pumping stage (15), the differential pumping stage (16) and the differential pumping stage (17). The incorporation of a channel (70) with asymmetric openings between the target and the adjacent differential pumping stages results in reduced pumping requirements and lower base pressures in the stages (15), (16) and (17). The incorporation of a jet deflector component further reduces gas transport between the target and the multiple connected differential stages.

[0030] 8 shows the use of a channel (70) with an asymmetric opening for gas jet deflection in a mass spectrometer. The mass spectrometer consists of a sample chamber (19) separated from an ionization chamber (20) by a differential pumping stage (21) and a differential pumping stage (22). The asymmetric opening located between the stages (19) and (21) deflects the gas, allowing the sample chamber to operate at high pressures and the ionization chamber to operate at high vacuum levels, and generally eliminating gas jetting phenomena that would normally occur between the stages (20), (21) and (22).

Claims

1. disposing a gas deflector between a first region and a second region of the pressurizable system; operating the pressurizable system such that the pressurizable system is pressurized and the first region is at a higher pressure than the second region, whereby a blast of gas travels from the first region to the second region through a channel in the gas deflector plate and enters the second region by exiting an asymmetric opening formed in the gas deflector plate; A method comprising:

2. The gas deflector includes: a first surface facing the first region; and a second surface facing the second region; and Including, The method of claim 1 , wherein the channel extends through the gas deflector plate having a first opening at the first surface and the asymmetric opening at the second surface.

3. the gas deflection plate has longitudinal and lateral axes extending through the gas deflection plate and parallel to the first and second surfaces; the gas deflector has a vertical axis perpendicular to the longitudinal and horizontal axes; The method of claim 2 , wherein gas traveling through the channels from the first region to the second region enters the second region at an angle offset from the normal axis.

4. The method of claim 3 , wherein the angular offset is at least 15 degrees.

5. the asymmetric opening is formed from a first portion and a second portion of the channel; the first portion is opposite the second portion across the asymmetric opening; The method of claim 3 , wherein the second portion has a greater angular deviation from the normal axis than the first portion.

6. The method of claim 1 , wherein no physical components obstruct the blast of gas exiting the channel and into the second region.

7. The method of claim 1 , further comprising coupling a jet deflector component to the gas deflector plate.

8. The method of claim 7 , wherein the jet deflector component is disposed in the second region.

9. the jet deflector component includes a surface; The method of claim 8 , wherein the jet of gas entering the second region impacts the surface of the jet deflector component and is redirected in a different direction.

10. The method of claim 9 , wherein the surface has a shape selected from the group of flat, concave, convex, and textured shapes.

11. The jet deflector component further includes a first mounting component; the gas deflector further comprises a second mounting component; The method of claim 7 , wherein the first mounting component and the second mounting component enable the jet deflector component to be attached to the gas deflector plate.

12. 2. The method of claim 1, wherein the pressurizable system is selected from the group consisting of a gas-target particle accelerator, a mass spectrometer, and a windowless nozzle.

13. The method of claim 1 , wherein the gas deflector is disposed between a target chamber and a differential pumping system.

14. The method of claim 1 , wherein the gas deflector is disposed between a sample chamber and a differential pumping stage.

15. The method of claim 2 , wherein the first opening has a diameter of 6 to 18 mm.

16. The method of claim 2, wherein the gas deflector has a thickness between the first surface and the second surface of between 13 and 40 mm.

17. The method of claim 1 , wherein the gas deflector has a circular or nearly circular shape.

18. The method of claim 1 , wherein most or all of the gas deflector plate is made of metal.

19. 20. The method of claim 18, wherein the metal is selected from the group consisting of copper, tungsten and stainless steel.

20. The method of claim 1 , wherein the gas deflector plate includes one or more openings that allow for attachment to the first region and / or the second region.

Images