CN201134410Y - Area Array Ion Storage System - Google Patents

Abstract

Disclosed is an area array ion storage system, which includes: an ion generating part; an ion storage part, including: a first end electrode electrically connected to the ion generating part, formed to have a plurality of holes; a second end electrode, formed as Having a plurality of holes; an intermediate electrode formed to have a plurality of holes; a first insulator formed in a ring shape, sandwiched between the first terminal electrode and the intermediate electrode, and insulating the two; a second insulator formed in a ring shape , sandwiched between the middle electrode and the second end electrode, and make the two insulated. According to the utility model, since the ion storage part is made relatively thin, the uniformity of ion extraction is facilitated, and the broadening of ion mobility spectrum peaks is reduced. In addition, since the first insulator and the second insulator have a large hole, ions avoid collisions with the insulating materials on both sides when the storage space oscillates or thermally moves, thereby preventing the storage caused by charge transfer and charge accumulation discharge on the insulator. Instability and loss of ions.

Description

Area Array Ion Storage System

technical field

The utility model relates to an ion storage system of a detection device using ion migration technology to detect drugs and explosives, belonging to the technical field of safety detection.

Background technique

The ion mobility spectrometer realizes the resolution of ions according to the difference in drift speed of different ions under a uniform weak electric field. The use of ion storage makes the sensitivity of the ion mobility spectrometer reach the picogram level. Existing ion storage such as US Patent 5200614 and Chinese Patent 200310106393.6 all suffer from ion loss due to poor boundary conditions of the electric field.

The ion trap used in mass spectrometry is usually composed of end electrodes on both sides and a middle hole electrode, and the voltage applied to the two end electrodes and the middle hole electrode is adjusted to realize the storage and extraction of ions. US Patent 6124592, which is close to the ion trap used in mass spectrometry, provides a single ion storage method in the case of large-diameter ionization regions and migration regions. Due to the need to meet the storage potential requirements, the storage region is larger, and the distance traveled by ions is longer. Long, so a longer opening time and a higher voltage are required, and the starting point and inconsistency of different ions entering the migration region are relatively large.

In addition, the area array storage provided by US Patent No. 6,933,498 improves ion storage efficiency. However, since the insulator with holes corresponding to the ion trap is sandwiched between the end electrode and the intermediate electrode, the ions will collide with the insulator to cause charge transfer and accumulation and then discharge, resulting in unstable ion storage. affect the sensitivity.

Utility model content

In order to solve the above-mentioned problems in the prior art, the purpose of this utility model is to provide an area array ion storage system of an ion mobility spectrometer, which can better improve sensitivity and resolution.

In one aspect of the present utility model, an area array ion storage system is proposed, including: an ion generating part; an ion storage part, including: a first terminal electrode electrically connected to the ion generating part, formed to have a plurality of holes; The two terminal electrodes are formed to have a plurality of holes; the middle electrode is formed to have a plurality of holes; the first insulator is formed in a ring shape, sandwiched between the first end electrode and the middle electrode, and insulates the two; the second The insulator, formed in a ring shape, is sandwiched between the intermediate electrode and the second terminal electrode and insulates the two.

Preferably, the diameter D1 of the hole of the intermediate electrode is 1 to 2 times the thickness L2 of the storage portion.

Preferably, $\mathrm{D.}1=\sqrt{2}L2.$

Preferably, the ion generating part includes at least one of the following: nickel 63, corona discharge source, laser, ultraviolet light, X-ray.

Preferably, a first voltage is applied to the ion generating part and the first end electrode, a second voltage is applied to the intermediate electrode, and a fixed voltage is applied to the second end electrode.

Preferably, the area array ion storage system further includes a plurality of ring electrodes spaced apart from the second terminal electrode, wherein uniformly varying voltages are applied to the plurality of ring electrodes.

Preferably, the first voltage and the second voltage are floatable and have a voltage difference between them.

Because the utility model adopts the above scheme, for the common ion mobility spectrometer, the ion storage part is made relatively thin to facilitate ion extraction under the premise of meeting the voltage conditions required for ion storage and without reducing the storage efficiency. It reduces the broadening of the ion mobility spectrum peaks, which is beneficial to the resolution.

In addition, since the insulating materials of the first insulator and the second insulator are formed to have a large hole, ions cannot collide with the insulating materials on both sides when the storage space oscillates or thermally moves, which will not cause charge transfer and charge on the insulators. Storage instability and ion loss due to accumulation discharge.

In the ion storage stage, the positive or negative ions to be collected drift to the middle electrode of the storage part of the array under the action of the electric field, where a plurality of non-electric field regions, namely ion storage spaces, are formed. In the ion export stage, the voltage of one end electrode and the middle electrode of the ion generation part and the array ion storage part is changed to push the ions from the storage area to the migration area, and then the overall voltage returns to the storage state.

Description of drawings

Fig. 1 is a schematic cross-sectional view of an area array ion storage system according to an embodiment of the present invention;

Fig. 2 is the schematic cross-sectional view of the ionization region and the array storage region in the system as shown in Fig. 1;

3A to 3F are schematic diagrams of the detailed structure of the ionization region and the array storage region shown in FIG. 2;

4 is a schematic diagram of the electrode potentials of the system according to an embodiment of the present invention in positive ion mode;

Fig. 5 is a schematic diagram of the voltage of each electrode changing with time when the system is in positive ion mode according to an embodiment of the present invention.

Detailed ways

The utility model will be further described below in conjunction with the accompanying drawings and specific embodiments. The utility model can work in both the negative ion mode and the positive ion mode. For the sake of convenience, this article only introduces the situation of the positive ion mode.

Referring to Fig. 1 and Fig. 2, the area array ion storage system according to the embodiment of the present utility model includes an ion generating part 1, an area array storage part 2, a group of ring electrodes 3, a Faraday disk 4, etc. arranged in sequence.

The ion generating section 1 is an ionization source, which may be a source such as nickel 63, corona discharge, laser, ultraviolet light, X-ray, and the like.

As shown in Figure 2, the ion generating part 1 and the area array storage part 2 are integrated, including a grid of electrodes 5 arranged in sequence as shown in Figure 3A, and a first grid electrode 5 with a plurality of holes in the shape as shown in Figure 3B. Terminal electrode 6, the shape of the first annular insulator 7 as shown in Figure 3C, the shape of the intermediate electrode 8 with a plurality of holes as shown in Figure 3D, the shape of the second annular insulator 9 as shown in Figure 3E, the shape The second terminal electrode 10 with a plurality of holes is shown in FIG. 3F.

As shown in Figures 2 and 3, a plurality of holes on the two terminal electrodes 6 and 10 and the intermediate electrode 8 are arranged in one-to-one correspondence, and the two insulators 7 and 9 only connect the first and second terminal electrodes 6 and 9 at the peripheral part. 10 is spaced and electrically insulated from the middle electrode 8, while there is only one large hole in the middle of the first and second insulators 7 and 9, thereby forming a ring-shaped insulator. In this way, since the insulating material on both sides is a large hole, the ions cannot collide with the insulating materials on both sides when the storage space is oscillating or thermally moving, which will not cause storage instability and storage instability caused by charge transfer and charge accumulation and discharge on the insulator. ion loss.

In addition, the ion generating section 1 is mechanically and electrically connected to one side of the array storage section 2 . The ion storage part 2 is formed in a relatively thin form, which facilitates the uniform extraction of ions and reduces the broadening of ion mobility spectrum peaks. There is a certain voltage difference between the voltages applied to the first end electrode 6 and the middle electrode 8 of the ion generating part 1 and the area array storage part 2, and the voltages applied thereto can float. The second end electrode 10 of the area array storage part 2 is applied with a fixed voltage, The ring electrode 3 is applied with a uniform and decreasing voltage to form a migration region.

The shape of the holes formed in the above-mentioned terminal electrodes is preferably a round hole, of course, including various types of holes, such as hexagonal holes, square holes, etc., preferably satisfying that D1 is equal to 1 to 2 times L2, and L2 is less than 5mm. preferred $\mathrm{D.}1=\sqrt{2}L2,$ Where D1 is the hole diameter of the middle electrode 8 or the effective hole diameter in other shapes, L2 is the distance between the two end electrodes 6 and 10, and L1 and L2 are selected according to the actual situation.

Referring to Fig. 2 and Fig. 4, the reference numeral 11 represents the voltage applied on the ion generating part 1 and the first end electrode 6, the reference numeral 12 represents the DC bias of the radio frequency voltage applied on the intermediate electrode 8, and the voltage 11 and 12 is able to float. In addition, a fixed voltage 13 is applied to the second terminal electrode 10 . The second terminal electrode 10 and the ring electrode 3 are applied with a uniformly decreasing voltage 14 to form a transition zone. The dotted line shown in Figure 4 is the voltage of each node when ions are extracted, the solid line is the voltage of each node in the storage stage, and the solid line 14 is the voltage of each point in the migration region, which remains constant during storage and extraction.

In the ion storage stage, an equal voltage 11 is applied to the first end electrode 6 and the second end electrode 10 , and a radio frequency voltage 12 with a DC bias voltage lower than the voltage 11 is applied to the middle electrode 8 . In this way, the positive ions will move to the formed potential well 12 for storage, and the bias voltage of the voltage 12, the frequency and the amplitude of the radio frequency voltage can be adjusted to form a suitable potential well depth. In other words, in the ion storage stage, the positive or negative ions to be collected drift to the middle electrode 8 of the array storage part 2 under the action of the electric field, where a plurality of non-electric field regions, namely ion storage spaces, are formed.

When the voltages 11 and 12 applied on the first terminal electrode 6 and the intermediate electrode 8 are increased from the solid line to the voltage shown by the dotted line, and the radio frequency voltage component of 12 is turned off, the ions are introduced into the migration region for drift and resolution. , and then the overall voltage returns to the voltage in the storage state.

Referring to Fig. 5, reference numeral 15 represents the time-varying waveform of the applied voltage on the ion generating part 1 and the first terminal electrode 6, and the reference numeral 16 represents the time-varying waveform of the applied voltage on the intermediate electrode 8, the accompanying drawings Mark 17 represents the waveform of the voltage applied to the second terminal electrode 10 as a function of time.

During the storage phase, the voltage 15 applied to the ion generating part 1 and the first end electrode 6 and the voltage 17 applied to the second end electrode 10 are equal and higher than the voltage 16 applied to the middle electrode 8, as shown in the upper right corner of FIG. 5 The enlarged diagram of is the RF waveform superimposed by the DC bias voltage, which can be a square wave, a sine wave, a sawtooth wave, etc. The ions are stored in multiple zero electric field regions of the middle electrode 8 .

In the ion extraction phase, the voltage 15 applied to the ion generating part 1 and the first end electrode 6 and the voltage 16 applied to the intermediate electrode 8 are higher than the voltage 17 applied to the second end electrode 10, and the voltage 16 is removed at this time. Without the AC component, ions are pushed out of the storage region into the migration region.

Because the utility model adopts the above-mentioned scheme, for the common ion mobility spectrometer, the ion storage part is made relatively thin to facilitate the uniform extraction of ions under the premise of meeting the voltage conditions required for ion storage and without reducing the storage efficiency. It reduces the broadening of the ion mobility spectrum peaks, which is beneficial to the resolution.

In addition, since the insulating materials of the first insulator 7 and the second insulator 9 have large pores to facilitate the movement of ions, the ions cannot collide with the insulating materials on both sides when the storage space is oscillating or thermally moving, thus causing no charge transfer. Storage instability and ion loss due to charge accumulation discharge on the insulator.

In the ion storage stage, the positive or negative ions to be collected drift to the middle electrode 8 of the array storage part 2 under the action of the electric field, where a plurality of non-electric field regions, namely ion storage spaces, are formed. In the ion extraction stage, the voltage of the first end electrode 6 and the middle electrode 8 of the ion generating part 1 and the array ion storage part 2 are changed to push ions from the storage area to the migration area, and then the overall voltage returns to the storage state.

It should be noted that the above embodiments are only used to illustrate and not limit the technical solutions of the present utility model, although the present utility model has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: the present utility model can still be carried out Modifications or equivalent replacements, any modifications or partial replacements that do not depart from the spirit and scope of the present invention shall be covered by the claims of the present invention.

Claims (7)

1. An area array ion storage system, comprising: Ion generating part (1); It is characterized in that it also includes: an ion storage part (2), including: a first terminal electrode (6) electrically connected to the ion generating part (1), formed to have a plurality of holes; The second terminal electrode (10) is formed to have a plurality of holes; an intermediate electrode (8) formed with a plurality of holes; The first insulator (7), formed in a ring shape, is sandwiched between the first terminal electrode (6) and the intermediate electrode (8), and insulates the two; The second insulator (9), formed in a ring shape, is sandwiched between the intermediate electrode (8) and the second terminal electrode (10), and insulates the two. 2. The area array ion storage system according to claim 1, characterized in that the diameter D1 of the hole of the middle electrode (8) is 1 to 2 times the distance L2 between the two electrodes. 3. The area array ion storage system according to claim 2, characterized in that $\mathrm{D.}1=\sqrt{2}L2.$ 4. The area array ion storage system according to claim 1, characterized in that the ion generating part (1) comprises at least one of the following: nickel 63, corona discharge source, laser, ultraviolet light, X-ray. 5. The area array ion storage system according to claim 1, characterized in that a first voltage is applied to the ion generating part (1) and the first end electrode (6), and the middle electrode (8) is A second voltage is applied, and a fixed voltage is applied to the second terminal electrode (10). 6. The area array ion storage system according to claim 5, characterized in that it further comprises a plurality of ring electrodes (3) spaced apart from the second terminal electrode (10), wherein the plurality of ring electrodes ( 3) A uniformly varying voltage is applied to it. 7. The area array ion storage system of claim 5, wherein the first voltage and the second voltage are capable of floating and there is a voltage difference between them.

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