阅读说明：本技术 一种在超高真空系统内精确气体进样、采集的分析装置 (Analysis device for accurate gas sample introduction and collection in ultrahigh vacuum system ) 是由 董珊珊 周传耀 夏树才 于 2020-07-09 设计创作，主要内容包括：本发明属于表面化学技术领域,特别涉及一种在超高真空系统内精确气体进样、采集的分析装置。包括气路装置、定量给料器装置、残余气体分析仪装置、激光器及超高真空腔体,其中气路装置和定量给料器装置连接,定量给料器装置接入超高真空腔体内,用于给样品的表面提供吸附气体；残余气体分析仪与铜罩子组合安装在超高真空腔体上,用于精准探测样品表面脱附出的气体；超高真空腔体上有预留的窗口,激光器发射的激光通过窗口照射至样品的表面上进行光化学反应。本发明易操作,精确度高,可以灵活地在超高真空系统内以各种角度转动样品,结合外加光照,可进一步探测并分析表面化学反应产物。(The invention belongs to the technical field of surface chemistry, and particularly relates to an analysis device for accurately sampling and collecting gas in an ultrahigh vacuum system. The device comprises an air path device, a quantitative feeder device, a residual gas analyzer device, a laser and an ultrahigh vacuum cavity, wherein the air path device is connected with the quantitative feeder device, and the quantitative feeder device is connected into the ultrahigh vacuum cavity and used for providing adsorbed gas for the surface of a sample; the residual gas analyzer and the copper cover are combined and arranged on the ultrahigh vacuum cavity and used for accurately detecting gas desorbed from the surface of the sample; the ultrahigh vacuum cavity is provided with a reserved window, and laser emitted by the laser irradiates the surface of the sample through the window to carry out photochemical reaction. The invention is easy to operate, has high precision, can flexibly rotate the sample in various angles in an ultrahigh vacuum system, and can further detect and analyze the surface chemical reaction product by combining with external illumination.)

1. An analysis device for accurate gas sampling and collection in an ultrahigh vacuum system is characterized by comprising a gas path device (41), a quantitative feeder device (42), a residual gas analyzer device (43) and an ultrahigh vacuum cavity (44), wherein the gas path device (41) is connected with the quantitative feeder device (42), and the quantitative feeder device (42) is connected into the ultrahigh vacuum cavity (44) and is used for providing adsorption gas for the surface of a sample (30); the residual gas analyzer device (43) is arranged on the ultrahigh vacuum cavity (44) and is used for detecting gas desorbed from the surface of the sample.

2. The device for analyzing the precise gas sample introduction and collection in the ultrahigh vacuum system as claimed in claim 1, wherein the ultrahigh vacuum chamber (44) has a window (32) reserved thereon, and the laser emitted from the laser (31) can be irradiated onto the surface of the sample (30) through the window to generate the photochemical reaction.

3. The analytical device for precise gas sampling and collection in ultrahigh vacuum system as claimed in claim 1 or 2, wherein the gas path device (41) comprises a sample cell (1), a gas storage steel cylinder (12), a pressure gauge (13), a gas supply line and an exhaust system, wherein the sample cell (1) is connected with the gas storage steel cylinder (12) through the gas supply line, and the gas storage steel cylinder (12) is connected with the quantitative feeder device (42) through the gas supply line;

the pressure gauge (13) is arranged on the gas supply pipeline; the air supply pipeline and the air supply pipeline are both provided with control valves;

the exhaust system is connected with the air supplement pipeline and the air supply pipeline and used for exhausting redundant air in the air supplement pipeline and the air supply pipeline by the air pipeline device (41) so as to maintain a vacuum state.

4. The device for analyzing the precise gas sampling and collection in the ultrahigh vacuum system as claimed in claim 3, wherein the exhaust system comprises a molecular pump I (15), an exhaust pipeline (16), a first bypass pipeline, a second bypass pipeline and a third bypass pipeline;

the molecular pump I (15) is connected with an exhaust pipeline (16);

the first bypass line is connected between the exhaust line (16) and the gas make-up line;

the second and third bypass lines being connected in parallel between the exhaust line (16) and the gas supply line;

a pneumatic air inlet valve (10) and a pneumatic air outlet valve (11) are respectively arranged between the air supply pipeline and the second branch pipeline and between the air supply pipeline and the third branch pipeline;

and the first bypass pipeline, the second bypass pipeline and the third bypass pipeline are respectively provided with a control valve.

5. The analysis device for precise gas sampling and collection in the ultrahigh vacuum system as claimed in claim 1, wherein the quantitative feeder device (42) comprises a quantitative feeding pipeline (45), a gas flow rate control structure, a differential pumping structure (19), a one-dimensional translation stage I (26) and a gas injection structure, wherein the one-dimensional translation stage I (26) is installed on the ultrahigh vacuum chamber (44);

the quantitative feeding pipeline (45) is installed and penetrates through the one-dimensional translation table I (26), the rear end of the quantitative feeding pipeline (45) is connected with the gas circuit device (41), and the front end of the quantitative feeding pipeline penetrates through and is arranged in the ultrahigh vacuum cavity (44); the one-dimensional translation table I (26) is used for driving the quantitative feeding pipeline (45) to stretch back and forth in the ultrahigh vacuum cavity (44);

the gas flow rate control structure and the differential pumping structure (19) are arranged on the quantitative feeding pipeline (45), and the gas flow rate control structure is used for controlling the flow rate of gas; the differential pumping structure (19) is used for pumping away redundant gas in the dosing pipeline (45);

the gas injection structure is arranged in the ultrahigh vacuum cavity (44) and connected with the quantitative feeding pipeline (45), and the gas injection structure is used for uniformly outputting split gas and gas.

6. The analysis device for precise gas sampling and collection in ultra-high vacuum system according to claim 5, wherein the gas flow rate control structure comprises a small hole (18), and the diameter of the small hole (18) is smaller than that of the dosing pipeline (45).

7. The analysis device for accurate gas sampling and collection in the ultra-high vacuum system as claimed in claim 5, wherein the differential pumping structure (19) comprises a pumping tube I (25), a pumping tube II (22) and a molecular pump II (23), wherein the pumping tube I (25) and the pumping tube II (22) are connected in parallel between the molecular pump II (23) and the quantitative feeding pipeline (45).

8. The analysis device for accurate gas sampling and collection in the ultra-high vacuum system according to claim 5, wherein the gas injection structure comprises a gas distribution pipe (27), a gas injection pipe (17) and a microchannel plate (28), wherein the gas injection pipe (17) and the gas distribution pipe (27) are both connected to the end of the dosing pipeline (45), and the gas distribution pipe (27) is accommodated in the gas injection pipe (17);

a plurality of shunting holes (271) are formed in the side wall of the air distributing pipe (27) along the circumferential direction, and an end plate (272) is arranged at the end part of the air distributing pipe (27);

one end of the air injection pipe (17) is sleeved at the end part of the quantitative feeding pipeline (45), the other end of the air injection pipe is provided with a micro-channel plate (28), and a plurality of injection holes are distributed on the micro-channel plate (28).

9. The analytical device for precise gas sampling and collection in the ultra-high vacuum system according to claim 1, wherein the residual gas analyzer device (43) comprises a sharp-nose copper cover (33), a straight-tube copper cover (34), an emptying tube (36), a one-dimensional translation stage II (37) and a residual gas analyzer, wherein the one-dimensional translation stage II (37) is disposed on the ultra-high vacuum chamber (44);

the sharp-nose copper cover (33), the straight-barrel copper cover (34) and the hollow pipe (36) are sequentially connected and cover the outer side of the residual gas analyzer; a backflow groove (361) is arranged on the side wall of the hollowed pipe (36);

the residual gas analyzer is arranged on the one-dimensional translation table II (37) and can move back and forth in the ultrahigh vacuum cavity (44) through the driving of the one-dimensional translation table II (37).

10. The device for analyzing accurate gas sampling and collection in the ultra-high vacuum system as claimed in claim 9, wherein the front end of the sharp-nose copper cover (33) is provided with a gas collecting hole (331).

Technical Field

The invention belongs to the technical field of surface chemistry, and particularly relates to an analysis device for accurately sampling and collecting gas in an ultrahigh vacuum system.

Background

Under the reaction condition of the current actual vacuum system, the adsorption and desorption collection of surface gas with accurate quantification and further the study of surface chemical reaction are significant problems, because in the field of surface chemical experiments, the detection of different information of samples under the condition of ultrahigh vacuum is the basis of the study, a plurality of detecting instruments are arranged at different positions of a vacuum cavity, a window for irradiating the samples by laser generated by a laser system outside the vacuum cavity is reserved, and the laser penetrates through the window to irradiate incident light on the surfaces of the samples, so that the vacuum cavity needs a plurality of suitable windows, and in cooperation with the window, the flexibility of the positions of the samples is realized. The sample is positioned on the sample table, and the spatial position of the sample table can be changed by the movement of the sample table in an X, Y, Z axis and the rotation of the sample table along a Z axis, so that a set of interconnected devices which can not only meet the actual experiment cavity but also be convenient to operate is designed, and accurate calculation and deduction are needed during the initial instrument design.

There are three more common approaches to the development of prior art doser devices, differing in the selection of single capillaries, pinholes and capillary arrays. For a single capillary dispenser, (sorbent is directed to surface adsorption by the syringe needle.) because of its small aspect ratio, this type of dispenser emits highly directional sorbent when the distance from the sample is comparable to the length of the capillary, and provides excellent enhancement on a diffusion background). In most cases, the flux distribution of the sorbent is not uniform, which is unacceptable because surface diffusion does not regenerate uniform coverage. The pin hole dispenser provides adsorbed molecules to the sample through a hole in a thin metal foil welded to the end of the gas supply tube. The design flux of the pinhole is more uniform, but the enhancement is lower. A third arrangement utilizes an array of capillaries, which is a dense grid of parallel capillaries, mounted at the end of the gas supply tube, parallel to the surface of the adsorbent, as with the foils in the pin hole feeder. Wines et al used a third doser and designed to mount the residual gas analyzer directly below it, for which a capillary array was fixed directly above a hood parallel to the front of the residual gas analyzer, and obliquely in front of the sample to enable adsorption-followed desorption measurements without moving the sample and the two instruments. However, this method is very convenient and direct for detecting the adsorbed and desorbed molecules alone, and is inconvenient if the adsorbed molecules are followed by rotating the sample to illuminate or detect other surface properties.

According to the instrument design of John T.Yates, a temperature programmed desorption measurement is carried out on a residual gas analyzer device in a vacuum cavity, and a sharp-nose glass cover is arranged at the forefront end of the instrument, so that the adsorption of the surface of the cover during the initial temperature-raising desorption collection of gas can be reduced, the coverage of adsorbed molecules is influenced and quantitatively judged, and the gas desorbed from the surface of a sample can be collected in a centralized manner. This has been adopted in the design of other vacuum chamber instruments, but in the process of practical use, the glass cover has the problem of charge accumulation, which affects the experimental result. In addition, the glass cover cannot be made very small in size and difficult to process during processing in a common workshop, and the glass cover can be crushed by the sample table during use.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide an analysis apparatus for accurately sampling and collecting gas in an ultra-high vacuum system, so as to better design and use experimental instruments in the field of surface chemistry.

In order to achieve the purpose, the invention adopts the following technical scheme:

an analysis device for accurately sampling and collecting gas in an ultrahigh vacuum system comprises a gas path device, a quantitative feeder device, a residual gas analyzer device and an ultrahigh vacuum cavity, wherein the gas path device is connected with the quantitative feeder device, and the quantitative feeder device is connected into the ultrahigh vacuum cavity and used for providing adsorbed gas for the surface of a sample; the residual gas analyzer device is arranged on the ultrahigh vacuum cavity and used for detecting gas desorbed from the surface of the sample.

The ultrahigh vacuum cavity is provided with a reserved window, and laser emitted by a laser can irradiate the surface of the sample through the window to generate photochemical reaction.

The gas path device comprises a sample pool, a gas storage steel cylinder, a pressure gauge, a gas supplementing pipeline, a gas supply pipeline and an exhaust system, wherein the sample pool is connected with the gas storage steel cylinder through the gas supplementing pipeline, and the gas storage steel cylinder is connected with the quantitative feeder device through the gas supply pipeline;

the pressure gauge is arranged on the gas supply pipeline; the air supply pipeline and the air supply pipeline are both provided with control valves;

and the exhaust system is connected with the gas supplementing pipeline and the gas supply pipeline and is used for exhausting redundant gas on the gas supplementing pipeline and the gas supply pipeline by the gas pipeline device to maintain a vacuum state.

The exhaust system comprises a molecular pump I, an exhaust pipeline, a first bypass pipeline, a second bypass pipeline and a third bypass pipeline; the molecular pump I is connected with an exhaust pipeline; the first bypass pipeline is connected between the exhaust pipeline and the air supplementing pipeline;

the second bypass pipeline and the third bypass pipeline are connected in parallel between the exhaust pipeline and the air supply pipeline;

a pneumatic air inlet valve and a pneumatic air outlet valve are respectively arranged between the air supply pipeline and the second and third side branch pipelines;

and the first bypass pipeline, the second bypass pipeline and the third bypass pipeline are respectively provided with a control valve.

The quantitative feeder device comprises a quantitative feeding pipeline, a gas flow velocity control structure, a differential pumping structure, a one-dimensional translation table I and a gas injection structure, wherein the one-dimensional translation table I is arranged on the ultrahigh vacuum cavity;

the quantitative feeding pipeline is installed and penetrates through the one-dimensional translation table I, the rear end of the quantitative feeding pipeline is connected with the gas circuit device, and the front end of the quantitative feeding pipeline penetrates through and is arranged in the ultrahigh vacuum cavity; the one-dimensional translation table I is used for driving the quantitative feeding pipeline to stretch back and forth in the ultrahigh vacuum cavity;

the gas flow rate control structure and the differential pumping structure are arranged on the quantitative feeding pipeline, and the gas flow rate control structure is used for controlling the flow rate of gas; the differential pumping structure is used for pumping away redundant gas in the quantitative feeding pipeline;

the gas injection structure is arranged in the ultrahigh vacuum cavity and connected with the quantitative feeding pipeline, and the gas injection structure is used for distributing gas and uniformly outputting the gas.

The gas flow rate control structure includes an orifice having a diameter smaller than a diameter of the dosing line.

The differential pumping structure comprises a pumping pipe I, a pumping pipe II and a molecular pump II, wherein the pumping pipe I and the pumping pipe II are connected in parallel between the molecular pump II and the quantitative feeding pipeline.

The gas injection structure comprises a gas distribution pipe, a gas injection pipe and a microchannel plate, wherein the gas injection pipe and the gas distribution pipe are connected to the end part of the quantitative feeding pipeline, and the gas distribution pipe is accommodated in the gas injection pipe;

a plurality of shunting holes are formed in the side wall of the gas distributing pipe along the circumferential direction, and an end plate is arranged at the end part of the gas distributing pipe;

one end of the air injection pipe is sleeved at the end part of the quantitative feeding pipeline, the other end of the air injection pipe is provided with a microchannel plate, and a plurality of injection holes are distributed on the microchannel plate.

The residual gas analyzer device comprises a sharp-nose copper cover, a straight-barrel copper cover, an emptying pipe, a one-dimensional translation table II and a residual gas analyzer, wherein the one-dimensional translation table II is arranged on the ultrahigh vacuum cavity;

the sharp-nose copper cover, the straight-barrel copper cover and the emptying pipe are sequentially connected and cover the outer side of the residual gas analyzer; a backflow groove is formed in the side wall of the hollowed pipe;

the residual gas analyzer is arranged on the one-dimensional translation table II and can move back and forth in the ultrahigh vacuum cavity through the driving of the one-dimensional translation table II.

And the front end of the sharp-nose copper cover is provided with a gas collecting hole.

Compared with the prior art, the invention has the following advantages and beneficial effects:

1. the invention adopts the movable quantitative feeder device and the movable residual gas analyzer device, the one-dimensional translation table can move back and forth according to the experimental design requirements, and the proper one-dimensional translation table can be replaced according to the self requirements to change the moving range, so that the adsorption and the subsequent collection of desorbed molecules are better under the premise of less changing the sample position, and the telescopic quantitative feeder and the residual gas analyzer device can avoid the problems that other measurements are influenced and the collision is possible due to the design of the fixed position, and the two instruments can be installed on different angles of the ultrahigh vacuum cavity by designing the proper size, so that the two instruments are more flexible;

2. the front end of the residual gas analyzer is provided with the copper tip, the tip with a proper size can be designed to collect desorbed molecules into the residual gas analyzer, the copper cover is easy to process and convenient to detach and replace, no charge is accumulated in the experimental process, and the detection result is not influenced;

3. the invention intelligently controls the temperature through a program. The invention adopts LABVIEW multi-section programming and PID parameter to control temperature, can realize temperature rising/lowering and constant temperature process, and can control temperature rising/lowering rate in the temperature rising/lowering process.

4. The invention provides an analysis device for accurately sampling and collecting gas in an ultrahigh vacuum system, which provides a more flexible operation environment for experimental exploration in the field of surface chemistry.

Drawings

FIG. 1 is a schematic structural diagram of an analysis device for accurate gas sampling and collection in an ultra-high vacuum system according to the present invention;

FIG. 2 is a schematic view of a doser device of the present invention;

FIG. 3 is a schematic view of the structure of the gas-distributing pipe according to the present invention;

FIG. 4 is a cross-sectional view A-A of FIG. 3;

FIG. 5 is a schematic view of the tip copper hood of the residual gas analyzer apparatus of the present invention;

FIG. 6 is a schematic view showing the structure of a hollow tube of the residual gas analyzer apparatus according to the present invention;

FIG. 7 shows a first embodiment of the present invention adsorbed on TiO₂(110) CH of surface₃Heating desorption spectrogram of OH;

FIG. 8 is a schematic representation of the practice of the present inventionExample two adsorption to TiO₂(110) CH of surface₃OH、CH₃Heating desorption spectrogram of O; wherein the content of the first and second substances,

FIG. 8(A) shows TiO₂(110) Surface adsorption of CH₃Detecting a temperature-rising desorption spectrogram with the mass number of 31 after OH molecules;

FIG. 8(B) is TiO₂(110) Surface adsorption of CH₃Detecting a temperature-rising desorption spectrogram with the mass number of 29 after OH molecules are detected;

FIG. 8(C) is TiO₂(110) Surface adsorption of CH₃Detecting a temperature-rising desorption spectrogram with the mass number of 31 after O;

FIG. 8(D) is TiO₂(110) Surface adsorption of CH₃And detecting a temperature-rising desorption spectrogram with the mass number of 29 after O.

In the figure: 1 is a sample cell, 2 is a control valve a, 3 is a control valve b, 4 is a control valve c, 5 is a control valve d, 6 is a control valve e, 7 is a control valve f, 8 is a control valve g, 9 is a control valve h, 10 is a pneumatic air inlet valve, 11 is a pneumatic air outlet valve, 12 is an air storage steel cylinder, 13 is a pressure gauge, 14 is a full-range vacuum gauge, 15 is a molecular pump I, 16 is an exhaust pipeline, 17 is an air injection pipe, 18 is a small hole, 19 is a differential pumping structure, 20 is a tee joint, 21 is a flange I, 22 is an air extraction pipe II, 23 is a molecular pump II, 24 is a flange II, 25 is an air extraction pipe I, 26 is a one-dimensional translation table I, 27 is an air distribution pipe, 271 is a flow distribution hole, 272 is an end plate, 28 is a microchannel plate, 29 is an inner snap spring, 30 is a sample, 31 is a laser, 32 is a window, 33 is a copper cover with a nozzle, 331 is a hole, 332 is a connecting hole, 34 is a straight-cylinder residual copper filament analyzer, 36 is a hollow pipe, 361 is a return channel, 37 is a one-dimensional translation table II, 38 is a residual gas analyzer quadrupole rod, 39 is a residual gas analyzer controller, 40 is a computer, 41 is an air channel device, 42 is a quantitative feeder device, 43 is a residual gas analyzer device, 44 is an ultrahigh vacuum cavity, and 45 is a quantitative feeding pipeline.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in detail with reference to the accompanying drawings and specific embodiments.

As shown in fig. 1, the analysis device for accurate gas sampling and collection in an ultra-high vacuum system provided by the present invention comprises a gas path device 41, a quantitative feeder device 42, a residual gas analyzer device 43 and an ultra-high vacuum chamber 44, wherein the gas path device 41 is connected with the quantitative feeder device 42, and the quantitative feeder device 42 is connected into the ultra-high vacuum chamber 44 and is used for providing an adsorbed gas to the surface of a sample 30; the residual gas analyzer device 43 is mounted on the ultra-high vacuum chamber 44 for detecting the gas desorbed from the surface of the sample.

On the basis of the above embodiment, as shown in fig. 1, in the analysis apparatus for precise gas sampling and collection in an ultra-high vacuum system of the present invention, a window 32 is reserved on the ultra-high vacuum cavity 44, which is convenient for introducing laser emitted by the laser 31 outside the cavity and observing the condition of a sample in the vacuum cavity. Laser light emitted from the laser 31 is irradiated from the window 32 onto the surface of the sample 30 to perform a photochemical reaction. Wherein the vacuum degree in the ultra-high vacuum cavity 44 can be less than 2 x 10^-10mbar. The detection can be performed by rotating the sample 30 in the direction of the window 32, passing the conditioned laser 31 through, illuminating the sample, and then in the direction of the residual gas analyzer device 43.

In the embodiment of the present invention, as shown in fig. 1, the gas path device 41 includes a sample cell 1, a gas storage steel cylinder 12, a pressure gauge 13, a gas supply line and an exhaust system, wherein the sample cell 1 is connected to the gas storage steel cylinder 12 through the gas supply line, and the gas storage steel cylinder 12 is connected to the quantitative feeder device 42 through the gas supply line; the pressure gauge 13 is arranged on the air supply pipeline, and the air supply pipeline are both provided with control valves. The exhaust system is connected with the gas supply pipeline and the gas supply pipeline, and is used for exhausting redundant gas on the gas supply pipeline and the gas supply pipeline by the gas pipeline device 41 so as to maintain a vacuum state.

In an embodiment of the present invention, as shown in fig. 1, the exhaust system includes a molecular pump i 15, an exhaust pipe 16, a first bypass pipe, a second bypass pipe, and a third bypass pipe, wherein the molecular pump i 15 is connected to the exhaust pipe 16, the first bypass pipe is connected between the exhaust pipe 16 and the air supplement pipe, and the second bypass pipe and the third bypass pipe are connected in parallel between the exhaust pipe 16 and the air supply pipe; and a pneumatic air inlet valve 10 and a pneumatic air outlet valve 11 are respectively arranged between the air supply pipeline and the second and third side branch pipelines, and control valves are respectively arranged on the first, second and third side branch pipelines.

Specifically, a control valve g8, a control valve a2 and a control valve b3 are sequentially arranged on the air supply pipeline; the gas supply pipeline is provided with a control valve c4 and a control valve h 9; the first bypass pipeline is provided with a control valve d5, the second bypass pipeline is provided with a control valve e6, the third bypass pipeline is provided with a control valve f7, the control valve a2, the control valve b3, the control valve c4, the control valve d5, the control valve e6 and the control valve f7 are 1/2-inch control valves, and the control valve g8 and the control valve h9 are 1/4-inch control valves. The pneumatic air inlet valve 10 and the pneumatic air outlet valve 11 are controlled by electromagnetic valves, the exhaust pipeline 16 is made of stainless steel pipes, the molecular pump I15 is used for vacuumizing the whole gas circuit, the exhaust pipeline 16 is provided with a whole-course vacuum gauge 14, the whole-course vacuum gauge 14 can read the vacuum of the gas circuit in real time, and the vacuum of the gas circuit can reach 8x 10 after being baked by a heating belt^-9mbar。

Three control valves are arranged between the sample cell 1 and the gas storage steel cylinder 12, the manual control valve can roughly and quantitatively control the gas volatilized by the sample cell 1to flow into the gas storage steel cylinder 12, and two pneumatic valves controlled by the electromagnetic valve can be remotely controlled by a relay controlled by computer programming to determine the gas to flow into or discharge vacuum. The pressure of the gas in the gas cylinder 12 can be accurately read by the pressure gauge 13, and if the gas amount exceeds the preset value, the molecular pump I15 can be communicated by controlling the control valve d5 between the exhaust pipeline 16 and the gas cylinder 12, so that the gas can be discharged. The pneumatic valves controlled by the two solenoid valves can be remotely controlled by a relay programmed and controlled by a computer, the pneumatic air inlet valve 10 is controlled to accurately and quantitatively control the gas in the gas storage steel cylinder 12 to flow into the ultrahigh vacuum cavity 44, the pneumatic air outlet valve 11 is controlled to stop the gas sample from entering the ultrahigh vacuum cavity 44, and the gas is pumped out in time by controlling the control valve f7 between the pneumatic air outlet valve 11 and the exhaust pipeline 16.

In an embodiment of the present invention, as shown in fig. 1, the doser device 42 includes a dosing pipeline 45, a gas flow rate control structure, a differential pumping structure 19, a one-dimensional translation stage i 26 and a gas injection structure, wherein the one-dimensional translation stage i 26 is sealed onto the ultra-high vacuum chamber 44 through a copper ring and screws, so as to maintain a vacuum state. The quantitative feeding pipeline 45 is connected with the one-dimensional translation table I26 through a flange II 24, the rear end of the quantitative feeding pipeline 45 is connected with the air supply pipeline of the air pipeline device 41, and the front end of the quantitative feeding pipeline passes through and is arranged in the ultrahigh vacuum cavity 44; the one-dimensional translation stage I26 is used for driving the quantitative feeding pipeline 45 to extend and retract in the ultrahigh vacuum cavity 44. The gas flow rate control structure and the differential pumping structure 19 are arranged on the quantitative feeding pipeline 45, and the gas flow rate control structure is used for controlling the flow rate of gas; the differential pumping structure 19 is used for pumping away the redundant gas in the quantitative feeding pipeline 45; the gas injection structure is arranged in the ultrahigh vacuum cavity 44 and connected with the quantitative feeding pipeline 45, and the gas injection structure is used for distributing gas and uniformly outputting the gas.

Specifically, the gas flow rate control structure includes an orifice 18, the orifice 18 is located between the air passage device 41 and the doser device 42, and the diameter of the orifice 18 is smaller than that of the dosing pipeline 45, so that the gas inflow rate can be preliminarily controlled. In this embodiment, the diameter of the dosing line 45 is 6.35mm and the diameter of the orifice 18 is 70 μm.

In this embodiment, the differential pumping structure 19 includes a pumping pipe i 25, a pumping pipe ii 22 and a molecular pump ii 23, wherein the pumping pipe i 25 and the pumping pipe ii 22 are connected in parallel between the molecular pump ii 23 and the dosing pipeline 45.

Specifically, the quantitative feeding pipeline 45 is connected with the air suction pipe I25 through a tee joint 20, the protruding end of the tee joint 20 is connected with the flange I21 through a pipeline, and the flange I21 is connected with the air suction pipe II 22. The differential pumping mechanism 19 can pump back the unwanted gas in the dosing line 45 of the doser device 42 and further be pumped away by the molecular pump ii 23 to maintain the vacuum state.

In the embodiment of the present invention, as shown in fig. 2, the gas injection structure includes a gas distribution pipe 27, a gas injection pipe 17 and a microchannel plate 28, wherein the gas distribution pipe 27 is provided to allow the gas to flow more dispersedly before flowing into the microchannel plate 28. The gas lance 17 and the gas distribution tube 27 are each connected to an end of the dosing line 45, and the gas distribution tube 27 is accommodated in the gas lance 17. As shown in fig. 3-4, the side wall of the gas distribution pipe 27 is provided with a plurality of diversion holes 271 along the circumferential direction, and in this embodiment, the side wall of the gas distribution pipe 27 is provided with six diversion holes 271 along the circumferential direction, so that the gas provided by the dosing pipeline 45 is diverted into the gas injection pipe 17 through the six diversion holes 271. Preferably, the end of the air distribution pipe 27 is provided with an end plate 272, and the end plate 272 is used for buffering the air flow and further dispersing the air flow. One end of the air injection pipe 17 is sleeved on the end part of the quantitative feeding pipeline 45, the other end of the air injection pipe is provided with a micro-channel plate 28, and the micro-channel plate 28 is fixed through an inner snap spring 29. A plurality of injection holes are densely distributed on the microchannel plate 28, and the gas in the gas injection pipe 17 is uniformly injected from the injection holes on the microchannel plate 28. The one-dimensional translation stage I26 drives the quantitative feeding pipeline 45 to stretch in the ultrahigh vacuum cavity 44 until the microchannel plate 28 is positioned right in front of the nearest position of the sample 30, gas is dispersed more through the gas distribution pipe 27, and then the gas is sprayed onto the surface of the sample 30 more uniformly through the microchannel plate 28.

In the embodiment of the present invention, as shown in fig. 1, the residual gas analyzer device 43 includes a sharp-nose copper cover 33, a straight-tube copper cover 34, an emptying pipe 36, a one-dimensional translation stage ii 37 and a residual gas analyzer, wherein the one-dimensional translation stage ii 37 is installed on an ultrahigh vacuum chamber 44, the sharp-nose copper cover 33, the straight-tube copper cover 34 and the emptying pipe 36 are connected in sequence and cover the residual gas analyzer on the outer side, and the residual gas analyzer is installed on the one-dimensional translation stage ii 37 and can move back and forth in the ultrahigh vacuum chamber 44 by the driving of the one-dimensional translation stage ii 37 to move to a proper position right in front of the sample 30.

In this embodiment, the residual gas analyzer is an SRS RGA200 residual gas analyzer, and includes a residual gas analyzer filament 35, a residual gas analyzer quadrupole rod 38, and a residual gas analyzer controller 39, which are connected in sequence, where the residual gas analyzer filament 35 is located in the straight-tube copper cover 34, and the residual gas analyzer controller 39 is connected to a computer 40, and enters a programmed temperature control program written by the LABVIEW software.

As shown in fig. 5, the front end of the sharp-nose copper hood 33 is provided with a gas collection hole 331, the rear end is provided with a connection hole 332 for connecting with the straight-barrel copper hood 34, and the desorption gas enters the sharp-nose copper hood 33 through the gas collection hole 331.

As shown in fig. 6, a return channel 361 is provided on a side wall of the hollow tube 36, and the gas in the hollow tube 36 flows back into the ultra-high vacuum chamber 44 through the return channel 361.

The invention adopts the combination of the sharp-nose copper cover 33 and the straight-tube copper cover 34 to shield the filament at the front end of the residual gas analyzer, so as to collect desorbed molecules and detect the coverage of the molecules and reaction products. The return channel 361 of the emptying pipe 36 facilitates that collected gas can be discharged into the ultrahigh vacuum cavity 44 in time after being analyzed and is pumped away by a molecular pump in time so as to facilitate the detection of desorbed molecules at different temperatures in the linear temperature rise process, the whole detection body is moved to a proper position right in front of the sample 30 through the one-dimensional translation stage II 37, is externally connected with the SRS RGA200 residual gas analyzer controller 39, enters a programmed temperature rise desorption program written by LABVIEW software after being connected with the computer 40, and collects and stores signals of desorbed products on the surface of the linear temperature rise sample.

The working principle of the invention is as follows:

the vacuum in the main cavity can be less than 2 x 10^-10An ultra-high vacuum system with mbar, through the combination of the gas circuit device 41 and the quantitative feeder device 42, the quantitative feeder device 42 can change the position between the device and the surface of the sample 30 through the one-dimensional translation table I26, so that the gas can be accurately and quantitatively adsorbed on the surface of the sample, and the sample 30 can directly turn to the direction of the residual gas analyzer device 43 for collecting the temperature programmed desorption spectrum; the direction of laser irradiation window 32 can also be turned to, select suitable laser and shine sample 30 through window 32, after the surface chemical reaction is aroused, turn to the sample again and survey reactant and the product molecule after the chemical reaction in the direction of residual gas analysis appearance device 43, and this residual gas analysis appearance device 43 carries out the back-and-forth movement through one-dimensional translation platform II 37, sharp mouth copper cover 33 and straight section of thick bamboo copper cover 34 can avoid gaseous the gas to adhere to, and there is not electric charge accumulation effect, thereby the gaseous molecule of accurate collection sample surface desorption, the design of sharp mouth copper cover 33 can be improved according to the sample size, easy processing just is difficult for taking place and is similar to the condition such as the glass cover hits the bits of broken glass. Is particularly telescopicThe design of the impulse doser device and the residual gas analyzer device allows for more instrument operation and detection analysis. Wherein the linear temperature raising program is controlled by a five-axis ultrahigh vacuum sample table (PREVAC) with LABVIEW program where the sample is located.