CN114235938B - Ultra-low vacuum device of dynamic ion probe and implementation method - Google Patents
Ultra-low vacuum device of dynamic ion probe and implementation method Download PDFInfo
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- CN114235938B CN114235938B CN202111467679.1A CN202111467679A CN114235938B CN 114235938 B CN114235938 B CN 114235938B CN 202111467679 A CN202111467679 A CN 202111467679A CN 114235938 B CN114235938 B CN 114235938B
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Abstract
The invention discloses an ultralow vacuum device of a dynamic ion probe and an implementation method thereof. The dynamic ion probe main body unit comprises a rapid sample loading vacuum cavity, a middle stage loading vacuum cavity and a sample analysis vacuum cavity. Wherein the fast sample loading vacuum cavity and the intermediate stage loading vacuum cavity are provided with a tubular cold trap device, and the sample analysis vacuum cavity is provided with an annular cold trap device. The invention has the advantage of improving and adaptively maintaining the vacuum performance of the dynamic ion probe.
Description
Technical Field
The invention relates to an ultralow vacuum device of a dynamic ion probe and an implementation method.
Background
The geological sample measured by the ion probe is inevitably adsorbed with water vapor or hydrogen whether the sample is a slice or a glue injection target. The existing vacuum pump of the instrument has smaller pumping speed on water vapor, so that the water vapor and hydrogen in the sample chamber are enriched, and the vacuum degree of the vacuum cavity of the instrument is poor, thereby limiting the performance and the use efficiency of the instrument.
Disclosure of Invention
In order to solve the technical problems, the ultralow vacuum device of the dynamic ion probe and the implementation method provided by the invention are mainly used for improving the performance of a vacuum system of the dynamic ion probe, and improving the performance of the vacuum system by orders of magnitude so as to solve the sample analysis with low background requirements, such as water content analysis of anhydrous minerals, and the like, and can effectively reduce the interference of analysis elements and hydrogen on elements during isotope analysis.
The system comprises a dynamic ion probe main body unit, a vacuum equipment unit, a control unit and a liquid nitrogen refrigerating unit; the dynamic ion probe main body unit comprises a rapid sample loading vacuum cavity, a middle stage loading vacuum cavity and a sample analysis vacuum cavity; the rapid sample loading vacuum cavity is provided with a first cylindrical cold trap device, the intermediate stage loading vacuum cavity is provided with a second cylindrical cold trap device, and the sample analysis vacuum cavity is provided with an annular cold trap device; a first isolation valve and a second isolation valve are respectively arranged between the rapid sample loading vacuum cavity and the intermediate stage loading vacuum cavity and between the rapid sample loading vacuum cavity and the sample analysis vacuum cavity; during dynamic ion probe analysis, the sample stage to be analyzed is arranged in the annular center of the annular cold trap device.
The implementation steps are as follows:
step one: placing a sample to be tested in a quick sample loading vacuum cavity, and starting a vacuum equipment unit;
step two: judging whether the pressure of the rapid sample loading vacuum cavity is lower than a liquid nitrogen input threshold, if so, not conveying liquid nitrogen, and avoiding the phenomenon that the cold trap adsorbs too much water vapor to reduce the adsorption performance; when the liquid nitrogen input threshold value is lower than the liquid nitrogen input threshold value, conveying liquid nitrogen to a first cylindrical cold trap device;
step three: judging whether the pressure of the quick sample loading vacuum cavity is lower than a first opening threshold value of the isolation valve, opening the first isolation valve when the pressure is lower than the threshold value, pushing a sample to be tested into the intermediate stage loading vacuum cavity, and closing the first isolation valve;
step four: delivering liquid nitrogen to the second cylindrical cold trap device, judging whether the vacuum pressure of the intermediate-stage loading vacuum cavity is lower than the opening threshold value of the second isolation valve, opening the second isolation valve when the vacuum pressure is lower than the threshold value, pushing the sample to be tested into the sample analysis vacuum cavity, and closing the second isolation valve;
step five: delivering liquid nitrogen to the annular cold trap device, when the vacuum pressure of the sample analysis vacuum cavity meets the analysis requirement, performing ablation on the sample by adopting a primary ion beam, and analyzing generated secondary ions through a mass spectrum device and an acquisition system; in the whole analysis flow, the liquid nitrogen liquid level reading unit judges the liquid nitrogen liquid level by reading the position of the floater, and automatically conveys liquid nitrogen when the liquid nitrogen liquid level is lower than the lower limit 1/3 of the liquid nitrogen liquid level.
The beneficial effects of the invention are as follows: the invention provides an ultralow vacuum device of a dynamic ion probe and an implementation method thereof, which are used for improving the performance of a vacuum system of the dynamic ion probe, improving the performance of the vacuum system by orders of magnitude so as to solve the sample analysis of low background requirements, and the system can be applied to various dynamic ion probe instruments.
Drawings
Fig. 1: the dynamic ion probe ultra-low vacuum device forms a schematic diagram;
fig. 2: a cylindrical cold trap device structure diagram;
fig. 3: ring cold trap device structure diagram.
Detailed Description
The invention relates to a dynamic ion probe ultra-low vacuum device, which comprises a dynamic ion probe main body unit, a vacuum equipment unit, a control unit and a liquid nitrogen refrigerating unit. The dynamic ion probe main body unit comprises a rapid sample loading vacuum cavity 1-1, a middle stage loading vacuum cavity 1-4 and a sample analysis vacuum cavity 1-8. Wherein the quick sample loading vacuum cavity 1-1 and the middle stage loading vacuum cavity 1-4 are respectively provided with a tubular cold trap device 1-2 and a tubular cold trap device 1-5, and the sample analysis vacuum cavity is provided with an annular cold trap device 1-7. During dynamic ion probe analysis, the sample stage 1-10 to be analyzed is arranged in the annular center of the annular cold trap device 1-7. The control unit comprises a liquid nitrogen conveying control unit, a liquid nitrogen liquid level reading unit, a vacuum equipment control unit and a vacuum pressure reading unit; the liquid nitrogen refrigerating unit comprises a self-pressurizing liquid nitrogen device and low-temperature liquid nitrogen electromagnetic valves 1-9; the vacuum equipment unit comprises a vacuum pressure gauge group and a vacuum pump group.
An isolation valve 1-3 and an isolation valve 1-6 are arranged among the rapid sample loading vacuum chamber 1-1, the intermediate stage loading vacuum chamber 1-4 and the sample analysis vacuum chamber 1-8. The vacuum pressure gauge group and the vacuum pump group in the vacuum equipment unit are respectively communicated with the rapid sample loading vacuum cavity 1-1, the middle stage loading vacuum cavity 1-4 and the sample analysis vacuum cavity 1-8; the self-pressurizing liquid nitrogen device transmits liquid nitrogen to the cold trap device 1-2, the cold trap device 1-5 and the cold trap device 1-7 through the low-temperature liquid nitrogen electronic valve 1-9.
Fig. 2 is a schematic structural diagram of a tubular cold trap device, the tubular cold trap device 1-2 and the tubular cold trap device 1-5 are of a tee joint design, a vacuum cavity 2-2 of the tubular cold trap device 1-2 is in sealing connection with a quick sample loading vacuum cavity 1-1 through a CF flange end 2-3, the vacuum cavity 2-2 of the tubular cold trap device 1-5 is in sealing connection with a middle stage loading vacuum cavity 1-4 through the CF flange end 2-3, and the tubular liquid nitrogen cavity 2-1 is welded on an upper end face flange of the tee joint and is provided with an upper cover 2-4 with a liquid inlet and a liquid outlet. FIG. 3 is a schematic diagram of an annular cold trap device, wherein the annular cold trap device 1-7 is of a straight-through design, and an annular liquid nitrogen cavity 3-5 is welded on the inner wall of a liquid nitrogen inlet 3-1 and a liquid nitrogen outlet 3-2; the outer walls of the liquid nitrogen inlet 3-1 and the liquid nitrogen outlet 3-2 are welded and connected with the straight flange 3-4; the electrode flange 3-3 is welded with the through flange 3-4.
The sample loading vacuum chamber 1-1, the cylindrical cold trap device 1-2 and the cylindrical cold trap device 1-5 in the middle stage loading vacuum chamber 1-4, and the annular cold trap device 1-7 in the sample analysis vacuum chamber 1-8 are provided with liquid nitrogen liquid level floats; the liquid nitrogen conveying control unit judges the liquid nitrogen liquid level by judging the position of the floater, and conveys liquid nitrogen when the liquid nitrogen liquid level is lower than the lower limit 1/3 of the liquid nitrogen liquid level.
The vacuum of the quick sample loading vacuum cavity 1-1, the middle stage loading vacuum cavity 1-4 and the sample analysis vacuum cavity 1-8 is gradually reduced; and a lower limit of the vacuum pressure threshold is set, and the isolation valve 1-3 and the isolation valve 1-6 can be opened only when the vacuum pressure is lower than the threshold.
The implementation method comprises the following steps:
the first step: placing a sample to be tested in a quick sample loading vacuum cavity 1-1, and starting a vacuum equipment unit;
and a second step of: judging whether the pressure of the rapid sample loading vacuum cavity is lower than a liquid nitrogen input threshold, if so, not conveying liquid nitrogen, and avoiding the phenomenon that the cold trap adsorbs too much water vapor to reduce the adsorption performance; when the liquid nitrogen input threshold value is lower than the liquid nitrogen input threshold value, delivering liquid nitrogen to the cylindrical cold trap device 1-2;
and a third step of: judging whether the pressure of the quick sample loading vacuum cavity is lower than the opening threshold value of the isolation valve 1-3, opening the isolation valve 1-3 when the pressure is lower than the threshold value, pushing a sample to be tested into the intermediate stage loading vacuum cavity 1-4, and closing the isolation valve 1-3;
fourth step: delivering liquid nitrogen to the cylindrical cold trap device 1-5, judging whether the vacuum pressure of the intermediate-stage loading vacuum cavity is lower than the opening threshold value of the isolation valve 1-6, opening the isolation valve 1-6 when the vacuum pressure is lower than the threshold value, pushing a sample to be tested into the sample analysis vacuum cavity 1-8, and closing the isolation valve 1-6;
fifth step: and (3) delivering liquid nitrogen to the annular cold trap devices 1-7, and when the vacuum pressure of the sample analysis vacuum cavity meets the analysis requirement, adopting a primary ion beam to carry out ablation on the sample, and analyzing generated secondary ions through a mass spectrum device and an acquisition system. In the whole analysis flow, the liquid nitrogen liquid level reading unit judges the liquid nitrogen liquid level by reading the position of the floater, and automatically conveys liquid nitrogen when the liquid nitrogen liquid level is lower than the lower limit 1/3 of the liquid nitrogen liquid level.
Claims (3)
1. A dynamic ion probe ultra-low vacuum device comprises a dynamic ion probe main body unit, a vacuum equipment unit, a control unit and a liquid nitrogen refrigerating unit; the dynamic ion probe main body unit comprises a rapid sample loading vacuum cavity (1-1), a middle stage loading vacuum cavity (1-4) and a sample analysis vacuum cavity (1-8); the rapid sample loading vacuum cavity (1-1) is provided with a first cylindrical cold trap device (1-2), the intermediate stage loading vacuum cavity (1-4) is provided with a second cylindrical cold trap device (1-5), and the sample analysis vacuum cavity (1-8) is provided with an annular cold trap device (1-7); a first isolation valve (1-3) and a second isolation valve (1-6) are respectively arranged between the rapid sample loading vacuum cavity (1-1) and the intermediate stage loading vacuum cavity (1-4) and between the sample analysis vacuum cavities (1-8); during dynamic ion probe analysis, a sample stage (1-10) to be analyzed is arranged at the annular center of an annular cold trap device (1-7); the first cylindrical cold trap device (1-2) and the second cylindrical cold trap device (1-5) are of tee joint design, a vacuum cavity (2-2) of the first cylindrical cold trap device is connected with a quick sample loading vacuum cavity (1-1) or an intermediate stage loading vacuum cavity (1-4) in a sealing mode through a CF flange end (2-3), and the cylindrical liquid nitrogen cavity (2-1) is welded on an upper end face flange of the tee joint and provided with an upper cover (2-4) with a liquid inlet and a liquid outlet; the annular cold trap device (1-7) is of a straight-through design, the annular liquid nitrogen cavity (3-5) is welded on the inner wall of the liquid nitrogen inlet (3-1) and the liquid nitrogen outlet (3-2); the outer walls of the liquid nitrogen inlet (3-1) and the liquid nitrogen outlet (3-2) are welded with the straight-through flange (3-4); the electrode flange (3-3) is welded with the straight-through flange (3-4);
the control unit comprises a liquid nitrogen conveying control unit, a liquid nitrogen liquid level reading unit, a vacuum equipment control unit and a vacuum pressure reading unit; the liquid nitrogen refrigerating unit comprises a self-pressurizing liquid nitrogen device and a low-temperature liquid nitrogen electromagnetic valve (1-9); the self-pressurizing liquid nitrogen device conveys liquid nitrogen to the first cylindrical cold trap device (1-2), the second cylindrical cold trap device (1-5) and the annular cold trap device (1-7) through a low-temperature liquid nitrogen electronic valve; liquid nitrogen liquid level floats are arranged in the first cylindrical cold trap device (1-2), the second cylindrical cold trap device (1-5) and the annular cold trap device (1-7), the liquid nitrogen conveying control unit judges the liquid nitrogen liquid level by judging the positions of the floats, and liquid nitrogen is conveyed when the liquid nitrogen liquid level is lower than the lower limit of 1/3 of the liquid nitrogen liquid level.
2. The ultra-low vacuum device of the dynamic ion probe according to claim 1, wherein the vacuum equipment unit comprises a vacuum pressure gauge group and a vacuum pump group; the vacuum pressure gauge group and the vacuum pump group are respectively communicated with the rapid sample loading vacuum cavity (1-1), the intermediate stage loading vacuum cavity (1-4) and the sample analysis vacuum cavity (1-8); the vacuum of the rapid sample loading vacuum cavity (1-1), the intermediate stage loading vacuum cavity (1-4) and the sample analysis vacuum cavity (1-8) is gradually reduced; and a lower limit of the vacuum pressure threshold is set, and the first isolation valve (1-3) and the second isolation valve (1-6) can be opened only when the vacuum pressure is lower than the threshold.
3. The method for implementing the dynamic ion probe ultra-low vacuum device according to any one of claims 1-2, comprising the following steps:
step one: placing a sample to be tested in a quick sample loading vacuum cavity (1-1), and starting a vacuum equipment unit;
step two: judging whether the pressure of the rapid sample loading vacuum cavity is lower than a liquid nitrogen input threshold, if so, not conveying liquid nitrogen, and avoiding the phenomenon that the cold trap adsorbs too much water vapor to reduce the adsorption performance; delivering liquid nitrogen to the first tubular cold trap device (1-2) when the liquid nitrogen input threshold is lower;
step three: judging whether the pressure of the quick sample loading vacuum cavity is lower than the opening threshold value of the first isolation valve (1-3), opening the first isolation valve (1-3) when the pressure is lower than the threshold value, pushing a sample to be tested into the intermediate stage loading vacuum cavity (1-4), and closing the first isolation valve (1-3);
step four: delivering liquid nitrogen to the second cylindrical cold trap device (1-5), judging whether the vacuum pressure of the intermediate-stage loading vacuum cavity is lower than the opening threshold value of the second isolation valve (1-6), opening the second isolation valve (1-6) when the vacuum pressure is lower than the threshold value, pushing a sample to be tested into the sample analysis vacuum cavity (1-8), and closing the second isolation valve (1-6);
step five: delivering liquid nitrogen to an annular cold trap device (1-7), when the vacuum pressure of a sample analysis vacuum cavity meets the analysis requirement, adopting a primary ion beam to carry out ablation on the sample, and analyzing generated secondary ions through a mass spectrum device and an acquisition system; in the whole analysis flow, the liquid nitrogen liquid level reading unit judges the liquid nitrogen liquid level by reading the position of the floater, and automatically conveys liquid nitrogen when the liquid nitrogen liquid level is lower than the lower limit 1/3 of the liquid nitrogen liquid level.
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| DE4133121A1 (en) * | 1991-10-05 | 1993-04-08 | Inst Festkoerperphysik Und Ele | Precision focused ion probe for treatment of micro surfaces - has liquid phase emitter located in housing and accurately positioned relative to surface of specimen |
| JP2000090871A (en) * | 1998-09-16 | 2000-03-31 | Seiko Epson Corp | Doping method and device thereof |
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| US7205534B2 (en) * | 2002-10-25 | 2007-04-17 | Centre De Recherche Public-Gabriel Lippmann | Method and apparatus for in situ depositing of neutral Cs under ultra-high vacuum to analytical ends |
| JP2006114225A (en) * | 2004-10-12 | 2006-04-27 | Hitachi High-Technologies Corp | Charged particle beam device |
| JP4820996B2 (en) * | 2005-05-30 | 2011-11-24 | 大学共同利用機関法人自然科学研究機構 | Noble gas immobilization device and immobilization method |
| WO2007022265A2 (en) * | 2005-08-16 | 2007-02-22 | Imago Scientific Instruments Corporation | Atom probes, atom probe specimens, and associated methods |
| CN108037172B (en) * | 2017-11-10 | 2019-12-06 | 中国科学院广州地球化学研究所 | Method for simultaneously analyzing water content and oxygen isotope in zircon based on large-scale secondary ion mass spectrometry |
| WO2020113426A1 (en) * | 2018-12-04 | 2020-06-11 | 中国科学院地质与地球物理研究所 | Method and system for measuring inert gase using ion probe |
| CN113093264B (en) * | 2021-04-08 | 2024-04-30 | 北京大学 | Ion beam detector |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4133121A1 (en) * | 1991-10-05 | 1993-04-08 | Inst Festkoerperphysik Und Ele | Precision focused ion probe for treatment of micro surfaces - has liquid phase emitter located in housing and accurately positioned relative to surface of specimen |
| JP2000090871A (en) * | 1998-09-16 | 2000-03-31 | Seiko Epson Corp | Doping method and device thereof |
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