# US 12,119,215 B1 · Electrostatic ion trap

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 12,119,215 B1
- Document ID: US12119215B1
- Status: Granted
- Kind: B1
- Application number: 18/035,331
- Filed: 2022-05-18
- Published: 2024-10-17
- Granted: 2024-10-15
- Earliest claimed: 2021-11-30
- Assignees: Ningbo University
- Applicants: Ningbo University
- Inventors: Fu-Xing Xu; Li Ding
- Web page: https://patentgrep.com/patent/US12119215B1

## CPC

- H01J 49/4245: {Electrostatic ion traps (H01J49/422 takes precedence)}
- H01J 49/424: {Three-dimensional ion traps, i.e. comprising end-cap and ring electrodes}
- Y02A 50/2351: Atmospheric particulate matter [PM], e.g. carbon smoke microparticles, smog, aerosol particles, dust
- H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H)
- Y02A: TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE

## Abstract

The invention relates to an electrostatic ion trap having a central axis and a central symmetrical plane perpendicular to the central axis. The electrostatic ion trap comprises an inner electrode group arranged along the central axis and a pair of outer electrode groups arranged on two sides of the central symmetry plane along the central axis. Each outer electrode group comprises a plurality of electrode plates. The plurality of electrode plates are circumferentially distributed around a periphery of the inner electrode group and centered on the central axis. At least two electrode plates in the same outer electrode group are electrically connected. A potential difference is formed when voltages are respectively applied to the inner electrode group and the outer electrode groups, thereby forming a space for trapping ions between the inner electrode group and the outer electrode groups.

## Claims

### Claim 1

An electrostatic ion trap, comprising:
a central axis and a central symmetry plane perpendicular to the central axis;
an inner electrode group (1); and
a pair of outer electrode groups (2) arranged on two sides of the central symmetry plane along the central axis,
wherein each outer electrode group (2) comprises a plurality of electrode plates (2.1), the plurality of electrode plates (2.1) are circumferentially distributed around a periphery of the inner electrode group (1) and centered on the central axis, at least two electrode plates (2.1) in the same outer electrode group (2) are electrically connected, and a potential difference is formed when voltages are respectively applied to the inner electrode group (1) and the outer electrode groups (2), thereby forming a space (3) for trapping ions between the inner electrode group (1) and the outer electrode groups (2).

### Claim 2 (depends on 1)

The electrostatic ion trap of claim 1, wherein the inner electrode group (1) comprises a central electrode (1.1), the central electrode (1.1) being arranged along with the central axis.

### Claim 3 (depends on 1)

The electrostatic ion trap of claim 1, wherein the inner electrode group (1) comprises two central electrodes (1.1), the two central electrodes (1.1) being arranged centrosymmetrically about the central axis.

### Claim 4 (depends on 1)

The electrostatic ion trap of claim 1, wherein the pair of outer electrode groups (2) are symmetrically disposed on opposite sides of the central symmetry plane.

### Claim 5 (depends on 1)

The electrostatic ion trap of claim 1, wherein the plurality of electrode plates (2.1) of each outer electrode group (2) are evenly arranged on the periphery of the inner electrode group (1), wherein the electrode plates (2.1) of one of the pair of outer electrode groups (2) and the electrode plates (2.1) of another of the pair of the outer electrode groups (2) are staggered circumferentially.

### Claim 6 (depends on 1)

The electrostatic ion trap of claim 1, wherein both ends of the inner electrode group (1) are fixedly connected with two insulating end covers (4) respectively through threaded fasteners;
an insulating central ring sleeve (5) is arranged between the two insulating end covers (4) at a position, corresponding to the central symmetrical plane, of the periphery of the inner electrode group (1);
the electrode plates (2.1) of the outer electrode groups (2) are clamped between the insulating end covers (4) and the insulating central ring sleeve (5);
each electrode plate (2.1) has a clamping portion (2.1.3) integrally formed at one end corresponding to the insulating central ring sleeve (5), and a positioning portion (2.1.4) integrally and convexly formed at another end corresponding to the insulating end cover (4);
each insulating end cover (4) has an inner surface, a positioning step (4.1) integrally formed on an inner surface, and a plurality of radially extending positioning grooves (4.2) circumferentially formed on the inner surface and surrounding the positioning step (4.1);
each electrode plate (2.1) is abutted against and clamped with the insulating central ring sleeve (5) through the clamping portion (2.1.3); and
each electrode plate (2.1) is clamped with a respective one of the insulating end covers (4) through the positioning portion (2.1.4) of said electrode plate (2.1) received in the positioning groove (4.2) of said insulating end covers (4) such that an inner side of said electrode plate (2.1) is abutted against the positioning step (4.1) of said insulating end covers (4).

### Claim 7 (depends on 1)

The electrostatic ion trap of claim 1, wherein the electrode plates in each outer electrode group are characterized into a first outer electrode unit group (2.1A) and a second outer electrode unit group (2.1B), an adjustment potential difference is formed between the first outer electrode unit group (2.1A) and the second outer electrode unit group (2.1B) when voltages are applied to the first outer electrode unit group (2.1A) and the second outer electrode unit group (2.1B), and the electrode plates of the first outer electrode unit group (2.1A) and the electrode plates of the second outer electrode unit group (2.1B) are distributed alternatively.

### Claim 8 (depends on 7)

The electrostatic ion trap of claim 7, wherein
each electrode plate (2.1) of the first outer electrode unit group (2.1A) has a first arc-shaped structure at a side corresponding to the inner electrode group (1), the first arc-shaped structure of each electrode plate (2.1) of the first outer electrode unit group (2.1A) comprises a first arc-shaped segment (2.1.1) and a second arc-shaped segment (2.1.2);
each electrode plate (2.1) of the second outer electrode unit group (2.1B) has a second arc-shaped structure at a side corresponding to the inner electrode group (1), the second arc-shaped structure of the electrode plate (2.1) of the second outer electrode unit group (2.1B) comprises a first arc-shaped segment (2.1.1) and a third arc-shaped segment (2.1.5); and
a distance from the third arc-shaped segment (2.1.5) to the central axis is smaller than that from the second arc-shaped segment (2.1.2) to the central axis.

### Claim 9 (depends on 1)

The electrostatic ion trap of claim 1, wherein each electrode plate (2.1) on the incident path of ions into the space (3) in the outer electrode group (2) is provided with an entrance notch (6) to facilitate entry of the ions.

### Claim 10 (depends on 1)

The electrostatic ion trap of claim 1, wherein each electrode plate (2.1) is a hard metal plate having a thickness of 0.5 mm to 2 mm, made by an electric spark cutting process.