A two-stage differential vacuum chamber for molecular beam loading

Abstract

This utility model discloses a two-stage differential vacuum cavity for molecular beam loading, comprising a cavity body including a first sidewall, a second sidewall, a third sidewall, a fourth sidewall, a top wall, and a bottom wall. The first and third sidewalls are arranged opposite each other, as are the second and fourth sidewalls. Molecular beam inlets and outlets are respectively provided on the first and third sidewalls. A first vacuum port and a second vacuum port are respectively provided on the second and fourth sidewalls. A folded baffle is provided within the cavity, with its top edge connected to the top wall of the cavity and its bottom edge connected to the bottom wall. The intersection of the third and second sidewalls connects to one side of the folded baffle, and the intersection of the first and fourth sidewalls connects to the other side of the folded baffle. Differential circular holes are provided on the folded baffle. The folded baffle design maximizes the area of ​​the sidewall with the vacuum ports, providing a larger vacuum port.

Description

Technical Field

[0001] This utility model relates to the field of vacuum system device technology, specifically to a two-stage differential vacuum cavity for molecular beam loading, which is suitable for applications such as cold molecular ion physics research, molecular beam ionization and coulomb crystal preparation. Background Technology

[0002] In cold molecular ion physics research, molecular ions need to be prepared to low rotational dynamics, which is typically achieved using ultrasonic molecular beam technology for rotational cooling. However, if the ultrasonic molecular beam is directly introduced into the ion trap chamber, it will lead to insufficient vacuum, affecting the formation and trapping of coulomb crystals. Since the density of the ultrasonic molecular beam decreases significantly with increasing distance from the pulse valve, the greater the distance between the pulse valve and the ion trap, the lower the molecular beam density at the center of the ion trap, resulting in a lower ion loading rate.

[0003] Two-stage differential vacuum chambers achieve two-stage differential in a single vacuum chamber, effectively shortening the distance from the pulse valve to the ion trap chamber. Therefore, two-stage differential vacuum chambers have significant advantages in ultrasonic molecular beam cooling technology.

[0004] When a two-stage differential vacuum chamber is being evacuated, the size of the evacuation port diameter directly affects the evacuation effect; the larger the evacuation port diameter, the better the effect.

[0005] The patent document with publication number CN 119778228 A discloses a two-stage ultra-high vacuum differential pumping device based on a low-temperature pumping cold plate. The technical solution adopts a two-stage differential cavity by "installing a central partition in the vacuum container, which divides the vacuum container into a primary differential region and a secondary differential region". However, the central partition divides the plane on the wall where the vacuum pumping interface is set in two. Without expanding the cavity, the vacuum cavity can only provide a small vacuum pumping interface. Utility Model Content:

[0006] The purpose of this invention is to address the problems existing in the prior art by providing a two-stage differential vacuum cavity for molecular beam loading.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] A two-stage differential vacuum cavity for molecular beam loading includes a cubic cavity body. The cavity body includes a top wall, a bottom wall, and four side walls, designated as a first side wall, a second side wall, a third side wall, and a fourth side wall. The first and third side walls are positioned opposite each other, as are the second and fourth side walls. Molecular beam inlets and outlets are respectively located on the first and third side walls. A first vacuum port and a second vacuum port are respectively located on the second and fourth side walls. A folded baffle is disposed within the cavity, with its top edge connected to the top wall of the cavity. The top edge of the folded baffle blocks the top of the cavity. The wall is divided into a first top wall area and a second top wall area. The bottom edge of the folded baffle is connected to the bottom wall of the cavity. The bottom edge of the folded baffle divides the bottom wall of the cavity into a first bottom wall area and a second bottom wall area. The ridge line where the third side wall and the second side wall intersect is connected to one side edge of the folded baffle. The ridge line where the first side wall and the fourth side wall intersect is connected to the other side edge of the folded baffle. The first side wall, the second side wall, the first bottom wall area, the first top wall area, and the folded baffle form a first differential chamber. The third side wall, the fourth side wall, the second bottom wall area, the second top wall area, and the folded baffle form a second differential chamber. Differential circular holes are provided on the folded baffle.

[0009] The folded baffle includes a first inclined baffle, a straight baffle, and a second inclined baffle. The first inclined baffle, the straight baffle, and the second inclined baffle are all perpendicular to the top and bottom walls of the cavity. The straight baffle is located in the middle of the cavity and is arranged parallel to the first and third side walls. Differential circular holes are arranged on the straight baffle, extending in a direction perpendicular to the straight baffle and penetrating the straight baffle. The ridge line where the third and second side walls intersect is connected to one side of the first inclined baffle. The other side of the first inclined baffle is connected to one side of the straight baffle. The other side of the straight baffle is connected to one side of the second inclined baffle. The ridge line where the first and fourth side walls intersect is connected to the other side of the second inclined baffle.

[0010] The first top wall area is provided with a first vacuum gauge interface, and the second top wall area is provided with a second vacuum gauge interface.

[0011] A molecular beam collimator is provided on the flat baffle.

[0012] The molecular beam collimator includes a collimation cylinder and a collimation hole disposed within the collimation cylinder. The two ends of the collimation cylinder are the molecular beam collimator inlet and the molecular beam collimator outlet, respectively. The molecular beam collimator outlet is coaxially arranged with the differential circular hole. The molecular beam collimator is located on the side of the flat baffle facing the first differential chamber.

[0013] The flat baffle is provided with a circular mounting groove, which is coaxially arranged with the differential circular hole, and the molecular beam collimator is embedded in the circular mounting groove.

[0014] A collimator cover plate is provided on the outside of the molecular beam collimator, and the collimator cover plate is fixedly mounted on the flat baffle.

[0015] The collimator cover plate is provided with a central hole, the diameter of which is larger than the inner diameter of the collimator cylinder and smaller than the outer diameter of the collimator cylinder.

[0016] The molecular beam inlet, molecular beam outlet, first vacuum port, and second vacuum port are all provided with connecting flanges on their outer sides, which are located on the side wall of the cavity. The first vacuum gauge port and the second vacuum gauge port are also provided with vacuum gauge flanges on their outer sides, which are located on the top wall of the cavity.

[0017] The cavity and the folded baffle are both made of stainless steel.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0019] 1. By setting a folded partition, the side wall on the cavity where the vacuum port is set retains the maximum area, so that a larger vacuum port can be set compared with the traditional two-stage differential cavity without changing the cavity size.

[0020] 2. A molecular beam collimator is installed on the folded partition plate, which makes the molecular beam have better directionality and uniformity when entering the differential aperture, thereby improving the reliability of the system.

[0021] 3. The cavity is provided with a vacuum gauge interface, which can be set to monitor the vacuum level of the first differential chamber and the second differential chamber in real time, and the vacuum environment can be adjusted as needed;

[0022] 4. This utility model has a simple structure and is easy to operate. Attached Figure Description

[0023] Figure 1 This is an exploded view of the structure of this utility model;

[0024] Figure 2 This is a top view of the cavity connection. Figure 1 ;

[0025] Figure 3 This is a top view of the cavity connection. Figure 2 ;

[0026] Figure 4 This is a front view of the cavity;

[0027] Figure 5 This is a rear view of the cavity;

[0028] Figure 6 This is the left view of the cavity;

[0029] Figure 7 This is a schematic diagram of the molecular beam collimator.

[0030] Figure 8 This is a schematic diagram of the collimator cover plate.

[0031] Wherein, 1-cavity, 2-folded baffle, 3-first differential chamber, 4-second differential chamber, 5-first vacuum gauge interface, 6-second vacuum gauge interface, 7-molecular beam collimator, 8-collimator cover plate.

[0032] 101 - First sidewall, 102 - Second sidewall, 103 - Third sidewall, 104 - Fourth sidewall, 201 - Differential circular hole, 202 - Straight baffle, 203 - First inclined baffle, 204 - Second inclined baffle, 301 - Molecular beam inlet, 302 - First vacuum interface

[0033] 401 - Molecular beam outlet, 402 - Second vacuum port, 801 - Center hole of cover plate, 802 - Cover plate mounting hole. Detailed Implementation

[0034] To facilitate understanding and implementation of this utility model by those skilled in the art, the present utility model will be further described in detail below with reference to embodiments. The embodiments described herein are only for illustration and explanation and are not intended to limit the present utility model.

[0035] Example 1:

[0036] like Figure 1 , Figure 2 ,as well as Figure 3 As shown, a two-stage differential vacuum chamber for molecular beam loading includes a cubic cavity 1. The cavity 1 comprises a top wall, a bottom wall, and four side walls: a first side wall 101, a second side wall 102, a third side wall 103, and a fourth side wall 104. The first and third side walls are positioned opposite each other, as are the second and fourth side walls. A molecular beam inlet 301 and a molecular beam outlet 401 are respectively provided on the first and third side walls 101 and 103. A first vacuum port 302 and a second vacuum port 402 are respectively provided on the second and fourth side walls 102 and 104. Connecting flanges are provided on the outer sides of the molecular beam inlet 301, the molecular beam outlet 401, the first vacuum port 302, and the second vacuum port 402, and are located on the side walls of the cavity 1. In this embodiment, the dimensions of the cavity 1 are 203.2 mm (length × width × height).

[0037] A folded baffle 2 is provided in the cavity 1, dividing the cavity 1 into a first differential chamber 3 and a second differential chamber 4. The top edge of the folded baffle 2 is connected to the top wall of the cavity 1, dividing the top wall of the cavity 1 into a first top wall region and a second top wall region. The bottom edge of the folded baffle 2 is connected to the bottom wall of the cavity 1, dividing the bottom wall of the cavity 1 into a first bottom wall region and a second bottom wall region. The ridge line where the third side wall 103 and the second side wall 102 intersect is connected to one side edge of the folded baffle 2. Next, the intersecting edge of the first sidewall 101 and the fourth sidewall 104 connects to the other side of the folded baffle 2. The first sidewall 101, the second sidewall 102, the first bottom wall region, the first top wall region, and the folded baffle 2 form the first differential chamber 3. The third sidewall 103, the fourth sidewall 104, the second bottom wall region, the second top wall region, and the folded baffle 2 form the second differential chamber 4. The folded baffle 2 is provided with a differential circular hole 201, and the first differential chamber 3 and the second differential chamber 4 are connected through the differential circular hole 201. The molecular beam enters the first differential chamber 3 from the molecular beam inlet 301, passes through the differential circular hole 201 and enters the second differential chamber 4, and finally exits the second differential chamber 4 from the molecular beam outlet 401.

[0038] The folded baffle 2 includes a first inclined baffle 203, a straight baffle 202, and a second inclined baffle 204. The first inclined baffle 203, the straight baffle 202, and the second inclined baffle 204 are all perpendicular to the top and bottom walls of the cavity 1. The straight baffle 202 is located in the middle of the cavity 1 and is arranged parallel to the first side wall 101 and the third side wall 103. A differential circular hole 201 is provided on the straight baffle 202, extending perpendicularly to and penetrating the straight baffle 202. The ridge line where the third side wall 103 intersects the second side wall 102 connects to one side of the first inclined baffle 203. The other side of the first inclined baffle 203 connects to one side of the straight baffle 202, and the other side of the straight baffle 202 connects to the second side wall 103. One side of the inclined baffle 204 is connected, and the ridge line where the first sidewall 101 and the fourth sidewall 104 intersect is connected to the other side of the second inclined baffle 204. Since the sidewalls where the first vacuum port 302 and the second vacuum port 402 of the cavity 1 are located do not contact the folded baffle 2, when the folded baffle 2 separates the cavity 1, the sidewalls where the first vacuum port 302 and the second vacuum port 402 of the cavity 1 can retain the largest area. Thus, when the volume of the cavity 1 does not change, a larger vacuum port can be provided when the sidewalls where the first vacuum port 302 and the second vacuum port 402 of the cavity 1 are divided.

[0039] In some embodiments, both the cavity 1 and the folded baffle 2 are made of stainless steel. Stainless steel has excellent oxidation resistance at high temperatures, which can effectively prevent surface oxidation and extend service life. Stainless steel also has high mechanical strength and can withstand greater pressure and mechanical stress, which allows the vacuum differential cavity to withstand higher vacuum pressure differences, ensuring the stability and safety of the system.

[0040] The first and second top wall regions of the cavity 1 are respectively provided with a first vacuum gauge interface 5 and a second vacuum gauge interface 6. Vacuum gauge flanges are provided on the outer sides of both the first and second vacuum gauge interfaces 5 and 6. Vacuum gauge flanges are mounted on the top wall of the cavity 1, and vacuum gauges are installed on these flanges. The vacuum levels of the first differential chamber 3 and the second differential chamber 4 can be monitored in real time through these vacuum gauges. Since the folded baffle 2 is not a planar partition, the straight baffle 202 in the middle of the folded baffle 2 is parallel to the first side wall 101 and the third side wall 103. The area between the differential circular hole 201 and the first side wall 101 on the first top wall region is relatively large (compared to the area between the differential circular hole 201 and the first side wall 101 on the first top wall region when the folded baffle 2 is a planar partition). The area between the differential circular hole 201 and the third side wall 103 on the second top wall region is also relatively large (compared to the area between the folded baffle 2 and the first side wall 101 on the first top wall region when the folded baffle 2 is a planar partition). When the baffle 2 is a planar partition, the area on the second top wall between the differential circular hole 201 and the third side wall 103, the first vacuum gauge interface 5 and the second vacuum gauge interface 6 can be parallel to the straight line of the molecular beam inlet 301, the differential circular hole 201, and the molecular beam outlet 401, even with a small cavity volume 1. This allows for better monitoring of the vacuum level along the path of the straight line of the molecular beam inlet 301, the differential circular hole 201, and the molecular beam outlet 401.

[0041] Example 2:

[0042] To improve the directionality and uniformity of the incoming molecular beam, a molecular beam collimator 7 is installed on the flat baffle 202.

[0043] In this embodiment, the flat baffle 202 is 40mm wide and 20mm thick, which is sufficient to ensure the installation of the molecular beam collimator 7.

[0044] The diameter of the differential circular hole 201 is 10mm, and the depth of the differential circular hole 201 is 20mm, which is the thickness of the flat baffle 202.

[0045] The molecular beam collimator 7 includes a collimation cylinder and a collimation hole disposed within the collimation cylinder. The two ends of the collimation cylinder are the molecular beam collimator inlet and the molecular beam collimator outlet, respectively. The molecular beam collimator inlet is used to receive the molecular beam, and the molecular beam collimator outlet is coaxially disposed with the differential circular hole 201. The molecular beam collimator 7 is located on the side of the flat baffle 202 facing the first differential chamber 3.

[0046] like Figure 6 As shown, the collimation aperture is used for collimation and focusing of the molecular beam and serves as the channel for the molecular beam; the collimation cylinder provides mechanical support and facilitates installation. In this embodiment, the inner diameter of the collimation cylinder is 18.2 mm, the outer diameter is 22.2 mm, and the thickness is 0.2 mm.

[0047] To facilitate the installation of the molecular beam collimator 7, a circular mounting groove is provided on the flat baffle 202. The circular mounting groove is coaxially arranged with the differential circular hole 201, and the molecular beam collimator 7 is embedded in the circular mounting groove.

[0048] To reinforce the molecular beam collimator 7, a collimator cover plate 8 is provided on the outside of the molecular beam collimator 7, and the collimator cover plate 8 is fixedly mounted on the flat baffle 202.

[0049] like Figure 7 As shown, the collimator cover plate 8 is square. The collimator cover plate 8 is provided with a central hole 801 and a mounting hole 802. The diameter of the central hole 801 is larger than the inner diameter of the collimator cylinder and smaller than the outer diameter of the collimator cylinder. When the collimator cover plate 8 is fixed on the flat baffle 202, the collimator cover plate 8 presses the molecular beam collimator 7 onto the flat baffle 202.

[0050] In this embodiment, the collimator cover plate 8 has a side length of 30 mm and the diameter of the central hole 801 of the cover plate is 18.4 mm.

[0051] Everything else is the same as in Example 1.

[0052] In use, the molecular beam inlet 301 is fixedly connected to the molecular beam emitting device, the molecular beam outlet 401 is connected to the lower-level vacuum system, the first vacuum port 302 and the second vacuum port 402 are respectively connected to the vacuum pump, and the first vacuum gauge port 5 and the second vacuum gauge port 6 are respectively connected to the first vacuum gauge and the second vacuum gauge. The vacuum pump evacuates the first differential chamber 3 and the second differential chamber 4. The first vacuum gauge and the second vacuum gauge can be used to observe the vacuum level of the first differential chamber 3 and the second differential chamber 4, respectively. The molecular beam emitted by the molecular beam emitting device enters the first differential chamber 3 through the molecular beam inlet 301, passes through the molecular beam collimator 7, enters the differential circular hole 201, exits through the differential circular hole 201, enters the second differential chamber 4, and then exits through the molecular beam outlet 401 into the lower-level vacuum system.

[0053] It should be noted that the embodiments described in this utility model are merely illustrative examples of the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described embodiments or use similar methods to replace them, but without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A two-stage differential vacuum cavity for molecular beam loading, comprising a cavity (1), characterized in that, The cavity (1) is a cube, and includes a top wall, a bottom wall and four side walls. The four side walls are a first side wall (101), a second side wall (102), a third side wall (103) and a fourth side wall (104). The first side wall and the third side wall are arranged opposite each other, and the second side wall and the fourth side wall are arranged opposite each other. A molecular beam inlet (301) and a molecular beam outlet (401) are respectively provided on the first side wall (101) and the third side wall (103). A first vacuum port (302) and a second vacuum port (402) are respectively provided on the second side wall (102) and the fourth side wall (104). A folded baffle (2) is provided in the cavity (1). The top edge of the folded baffle (2) is connected to the top wall of the cavity (1). The top edge of the folded baffle (2) divides the top wall of the cavity (1) into a first top wall region. In the second top wall area, the bottom edge of the folded baffle (2) is connected to the bottom wall of the cavity (1). The bottom edge of the folded baffle (2) divides the bottom wall of the cavity (1) into the first bottom wall area and the second bottom wall area. The edge line where the third side wall (103) and the second side wall (102) intersect is connected to one side of the folded baffle (2). The edge line where the first side wall (101) and the fourth side wall (104) intersect is connected to the other side of the folded baffle (2). The first side wall (101), the second side wall (102), the first bottom wall area, the first top wall area, and the folded baffle (2) form the first differential chamber (3). The third side wall (103), the fourth side wall (104), the second bottom wall area, the second top wall area, and the folded baffle (2) form the second differential chamber (4). The folded baffle (2) is provided with a differential circular hole (201).

2. The two-stage differential vacuum cavity for molecular beam loading according to claim 1, characterized in that, The folded baffle (2) includes a first inclined baffle (203), a straight baffle (202), and a second inclined baffle (204); the first inclined baffle (203), the straight baffle (202), and the second inclined baffle (204) are all perpendicular to the top and bottom walls of the cavity (1). The straight baffle (202) is located in the middle of the cavity (1) and is parallel to the first side wall (101) and the third side wall (103). A differential circular hole (201) is provided on the straight baffle (202), and the differential circular hole (201) is along... The edge line of the third sidewall (103) and the second sidewall (102) that intersects is connected to one side of the first inclined baffle (203), the other side of the first inclined baffle (203) is connected to one side of the straight baffle (202), the other side of the straight baffle (202) is connected to one side of the second inclined baffle (204), and the edge line of the first sidewall (101) and the fourth sidewall (104) that intersects is connected to the other side of the second inclined baffle (204).

3. A two-stage differential vacuum cavity for molecular beam loading according to claim 1, characterized in that, The first top wall area is provided with a first vacuum gauge interface (5), and the second top wall area is provided with a second vacuum gauge interface (6).

4. A two-stage differential vacuum cavity for molecular beam loading according to claim 2, characterized in that, A molecular beam collimator (7) is provided on the flat baffle (202).

5. A two-stage differential vacuum cavity for molecular beam loading according to claim 4, characterized in that, The molecular beam collimator (7) includes a collimation cylinder and a collimation hole disposed in the collimation cylinder. The two ends of the collimation cylinder are the molecular beam collimator inlet end and the molecular beam collimator outlet end, respectively. The molecular beam collimator outlet end is coaxially disposed with the differential circular hole (201). The molecular beam collimator (7) is located on the side of the flat baffle (202) facing the first differential chamber (3).

6. A two-stage differential vacuum cavity for molecular beam loading according to claim 5, characterized in that, The flat baffle (202) is provided with a circular mounting groove, which is coaxially arranged with the differential circular hole (201), and the molecular beam collimator (7) is embedded in the circular mounting groove.

7. A two-stage differential vacuum cavity for molecular beam loading according to claim 6, characterized in that, The molecular beam collimator (7) is provided with a collimator cover plate (8) on the outside, and the collimator cover plate (8) is fixedly mounted on the flat baffle (202).

8. A two-stage differential vacuum cavity for molecular beam loading according to claim 7, characterized in that, The collimator cover plate (8) is provided with a cover plate center hole (801), the diameter of which is greater than the inner diameter of the collimator cylinder and smaller than the outer diameter of the collimator cylinder.

9. A two-stage differential vacuum cavity for molecular beam loading according to claim 3, characterized in that, The molecular beam inlet (301), molecular beam outlet (401), first vacuum port (302) and second vacuum port (402) are all provided with connecting flanges on the outside of the molecular beam inlet (301), the molecular beam outlet (401), the first vacuum port (302) and the second vacuum port (402), and the connecting flanges are provided on the side wall of the cavity (1). The first vacuum port (5) and the second vacuum port (6) are both provided with vacuum gauge flanges on the outside of the cavity (1), and the vacuum gauge flanges are provided on the top wall of the cavity (1).

10. A two-stage differential vacuum cavity for molecular beam loading according to claim 1, characterized in that, The cavity (1) and the folded baffle (2) are both made of stainless steel.

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