Composite structure of partitioned linear ion trap terminal electrode and partitioned linear ion trap

Abstract

The invention provides a composite structure of a partitioned linear ion trap end electrode and a partitioned linear ion trap composed of the composite structure. The partitioned linear ion trap sequentially comprises a first composite structure end electrode, a quadrupole trap, an intermediate connecting part, a multi-pole trap and a second composite structure end electrode according to the electrode space connection sequence. The first composite structure end electrode and the second composite structure end electrode are the same in structure and are each composed of a disc structure with a hole formed in the center and a rod structure with a hole formed in the center. The rod structure is fixed to the circle center of the disc structure and located in a space defined by the quadrupole trap or the multi-pole electrode rod. According to the invention, the requirement on the shuttle voltage can be reduced, and the generation of full-coverage axial trapping or pushing force on ions in the well region is ensured.

Description

Technical Field

[0001] The invention belongs to the field of time-frequency technology, and in particular relates to a composite structure of end electrodes of a partitioned linear ion trap, and a partitioned linear ion trap composed of the composite structure. Background Art

[0002] The working principle of a passive atomic clock is to use the atomic hyperfine energy level transition spectrum as the clock transition curve, and the modulated high-frequency signal as the microwave feed signal. The frequency difference between the microwave feed signal and the clock transition frequency corresponds to the atomic transition probability. For atomic clocks with atoms or ions as working materials, factors such as the Doppler effect, Dick effect, the number of signal measurements, and the free evolution time of ions or atoms during Ramsey detection are all important factors affecting the stability of the atomic clock. Ion trapped atomic clocks use static electricity, magnetic fields, or radio frequency fields added to electrodes of specific configurations to form an ion trap, which confines ions in an almost isolated and "uninterrupted" environment under ultra-high vacuum, which can greatly reduce the frequency shift caused by the collision between ions and the wall. It has the characteristics of high stability, low drift rate, light weight, and small size.

[0003] The partitioned linear ion trap is designed for ion-trapped atomic clocks. It divides the linear trap into two coaxial zones, the shorter of which is the pumping zone (quadrupole trap) and the longer of which is the microwave resonance zone (multipole trap). By changing the DC bias of the two zones, the trapped ions can be allowed to shuttle freely between the two zones along the central axis. The advantages of the partitioned linear trap are: (1) The ion density in the microwave resonance zone is reduced, and the second-order Doppler frequency shift is reduced. (2) The independent microwave resonance zone can be electromagnetically shielded to reduce the influence of external stray magnetic fields.

[0004] The end electrode design of the partitioned linear ion trap can adopt a disk electrode and a rod electrode structure. The disk electrode needs to be loaded with a higher shuttling voltage than the rod electrode, and the mortality rate during ion shuttling is relatively large; the rod electrode can obtain a higher ion shuttling efficiency, but it blocks the ion pumping light, affecting the ion pumping light intensity, which is not conducive to axial manipulation of ions.

[0005] It is necessary to design an electrode that takes into account the advantages of both coil and rod structures. Summary of the invention

[0006] In view of this, the present invention provides a composite structure of a partitioned linear ion trap end electrode, which solves the shortcomings of the disk electrode and the rod electrode, can reduce the requirements for the shuttle voltage, and ensure full coverage of the axial confinement or pushing force on the ions in the trap area.

[0007] In order to solve the above technical problems, the present invention is implemented as follows.

[0008] A composite structure of a partitioned linear ion trap end electrode comprises: the composite structure is composed of a disk structure with a central opening and a rod structure with a central opening; the rod structure is fixed at the center of the disk structure.

[0009] The present invention also provides a partitioned linear ion trap, which comprises a first composite structure end electrode, a quadrupole trap, an intermediate connecting component, a multipole trap and a second composite structure end electrode in order of the spatial connection order of the electrodes; the first composite structure end electrode and the second composite structure end electrode have the same structure, both consisting of a disk structure with a central opening and a rod structure with a central opening; the rod structure is fixed at the center of the disk structure and is located in the space surrounded by the electrode rods of the quadrupole trap or the multipole.

[0010] Preferably, the intermediate connecting component between the quadrupole trap and the multipole trap is an open-hole flange.

[0011] Preferably, direct current voltages are respectively loaded on the electrode rods of the multipole trap and the quadrupole trap, and after a shuttling potential difference is formed, the ions shuttle back and forth between the multipole trap and the quadrupole trap.

[0012] Beneficial effects:

[0013] (1) The present invention utilizes the structure of the disk electrode portion to ensure the intensity of the pumping light, making it easier to manipulate ions along the axial direction;

[0014] (2) Ensure that the ions in the trap are fully trapped or pushed in the axial direction;

[0015] (3) Reduced requirements for shuttle voltage;

[0016] (4) The present invention improves the performance of a partitioned linear ion trap and can be used in the design of a partitioned linear ion trap in an ion trapped atomic clock. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The diagram is a simulation diagram of the end electrodes of the disk structure and ion shuttling in the prior art; (a) is a structural diagram, and (b) is a simulation diagram of ion shuttling.

[0018] Figure 2 The diagrams are the simulation diagrams of the end electrodes of the rod structure and ion shuttling in the prior art; (a) is the structure diagram, and (b) is the simulation diagram of ion shuttling.

[0019] Figure 3 This is the hollow "rod + disk" structure end electrode structure of the present invention.

[0020] Figure 4 This is a simulation diagram of ion shuttling of the end electrode structure of the hollow "rod + disk" structure of the present invention. DETAILED DESCRIPTION

[0021] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0022] The present invention combines the advantages of disk electrodes and rod electrodes at the end of a partitioned linear ion trap, and proposes a composite structure of an end electrode of a partitioned linear ion trap. The composite structure adopts a hollow "rod + disk" design. The composite structure consists of a disk structure with a central opening and a rod structure with a central opening. The rod structure is fixed at the center of the disk structure, which solves the shortcomings of the disk electrode and the rod electrode. Through this composite structure, the requirements for the shuttle voltage can be reduced, and the axial confinement or pushing force of the ions in the trap area is guaranteed to be fully covered, thereby improving the performance of the partitioned linear ion trap.

[0023] like Figure 1-2 As shown, the partitioned linear ion trap consists of a quadrupole ion trap zone and a multipole ion trap zone. The two ion trap zones are connected in a coaxial straight line in space, and the middle connecting component is an open-hole flange.

[0024] The two end electrodes of the disk structure end electrode adopt a disk structure, the disk completely covers the quadrupole well and the multipole well, and the spatial connection sequence of the electrodes is disk structure-multipole well-opening flange-quadrupole well-disk structure.

[0025] The electrodes at both ends of the rod structure end electrode adopt a central rod structure, and the diameter of the central rod is smaller than the maximum spacing of the well electrodes. The order of the electrode space connection is rod structure-multipolar well-opening flange-quadrupole well-rod structure.

[0026] Figure 3 A partitioned linear ion trap using the above-mentioned hollow "rod + disk" structure end electrode is shown. The partitioned linear ion trap adopts a composite structure, consisting of a disk structure with a central opening and a rod structure. The rod structure is fixed at the center of the disk structure and is located in the space surrounded by the electrode rods of the quadrupole trap / multipole. The order of electrode space connection is "rod + disk" composite structure-multipole trap-opening flange-quadrupole trap-"rod + disk" composite structure. After DC voltage is applied to the electrode rods of the multipole trap and the quadrupole trap respectively to form a shuttle potential difference, ions shuttle back and forth between the multipole trap and the quadrupole trap.

[0027] from Figure 1 to Figure 3 It can be seen from the ion movement shuttling diagram that the hollow "rod + disk" end electrode can obtain a smaller ion distribution range after ion manipulation.

[0028] The present invention adopts a hollow "rod + disk" structure to design a partitioned linear ion trap end electrode. Compared with the method of using a disk or rod structure alone, it can reduce the requirements for the shuttle voltage, ensure full coverage of the axial confinement or pushing force on the ions in the trap area, and improve the performance of the partitioned linear ion trap.

[0029] The above specific embodiments only describe the design principle of the present invention. The shapes and names of the components in the description may be different and are not limited. Therefore, those skilled in the art in the field of the present invention may modify or replace the technical solutions recorded in the above embodiments; and these modifications and replacements do not deviate from the creative purpose and technical solutions of the present invention and should all fall within the protection scope of the present invention.

Claims

1. A composite structure of a partitioned linear ion trap end electrode, characterized in that: include: The composite structure consists of a disk structure with a central hole and a rod structure with a central hole; the rod structure is fixed at the center of the disk structure.

2. A partitioned linear ion trap, characterized in that: According to the order of spatial connection of the electrodes, the electrodes include a first composite structure end electrode, a quadrupole well, an intermediate connecting component, a multipole well, and a second composite structure end electrode in sequence; the first composite structure end electrode and the second composite structure end electrode have the same structure, both consisting of a disk structure with a central opening and a rod structure with a central opening; the rod structure is fixed at the center of the disk structure and is located in the space surrounded by the electrode rods of the quadrupole well or the multipole.

3. The partitioned linear ion trap according to claim 2, characterized in that: The intermediate connecting component between the quadrupole trap and the multipole trap is an open-hole flange.

4. The partitioned linear ion trap according to claim 2, characterized in that: DC voltage is loaded on the electrode rods of the multipole trap and the quadrupole trap respectively. After the shuttling potential difference is formed, the ions shuttle back and forth between the multipole trap and the quadrupole trap.

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