A free radical photoproduct testing device

Abstract

The invention relates to the field of spectral chemistry. A free radical photoproduct testing device comprises a laser, a droplet ejector, a vacuum chamber, an ion buncher I, an ion buncher II, an ion buncher III, an ion buncher IV, a quadrupole, a detector, a vacuum pump group I, a vacuum pump group II and a vacuum pump group III. A liquid reservoir resonance method is adopted to generate and eject droplets. The vibration direction of a driver is perpendicular to the direction in which the droplets are ejected. Droplets with a size much smaller than the inner diameter of a droplet ejection port can be formed. There is no special requirement for the polarity of a solvent. High voltage does not need to be applied during operation. A wide range of samples are applicable. A buffer chamber is added in the vacuum chamber to reduce the loss of an ion beam in the vacuum chamber as much as possible. A specially designed ion buncher can respectively perform ion introduction, trapping and ejection operations, effectively reducing the volume of the device and reducing the pumping speed of the vacuum pump group.

Description

Technical Field

[0001] The invention relates to the field of spectral chemistry, in particular to a free radical photoproduct testing device which has a special sample solution atomization method and can test photoreaction products of more types of free radicals. Background Art

[0002] Devices for studying the photoreaction products of molecules or free radicals usually study the ion beam of the molecules to be tested in a vacuum environment. It is usually necessary to atomize the solution containing the sample to be tested and then enter the vacuum environment. The first defect of the prior art: some devices in the prior art use the electrospray method to atomize the solution containing the sample to be tested, which has certain requirements on the solvent in the solution, that is, it must be a polar solution, and a high voltage must be applied to the liquid when the electrospray is working, which limits the types of samples applicable to the electrospray method; the second defect of the prior art: some devices in the prior art use the method of directly applying pressure to the liquid to make the liquid spray out and form droplets. The size of the droplets generated by this method is limited by the inner diameter of the droplet nozzle, that is, smaller droplets cannot be formed; the third defect of the prior art: in the ion beam test device in the prior art, a multi-stage vacuum pump group is usually used to evacuate different chambers. The vacuum difference between different chambers will cause the ion beam to form turbulence, thereby affecting the final detection efficiency. The free radical photoproduct test device described above can solve the problem. Summary of the invention

[0003] In order to solve the above problems, a free radical photoproduct testing device of the present invention adopts a liquid reservoir resonance method to generate and eject droplets, a buffer chamber is added to the vacuum chamber, and a specially designed ion buncher can respectively perform ion introduction, trapping and ejection operations, which effectively reduces the volume of the device and can reduce the pumping speed of the vacuum pump group.

[0004] The technical solution adopted by the present invention is:

[0005] The free radical photoproduct testing device mainly comprises a laser, a droplet ejector, a vacuum chamber, an ion buncher I, an ion buncher II, an ion buncher III, an ion buncher IV, a quadrupole, a detector, a vacuum pump group I, a vacuum pump group II, a vacuum pump group III and an ionization device. The vacuum chamber has a starting end and an end. In the vacuum chamber, there are a sampling chamber, a drift chamber I, a drift chamber II, a buffer chamber and a collision chamber in sequence from the starting end to the end. The sampling chamber, the buffer chamber and the collision chamber are respectively connected to the vacuum pump group III, the vacuum pump group II and the vacuum pump group I; the ion buncher I, the ion buncher II, the ion buncher III, the ion buncher IV and the quadrupole are all located in the vacuum chamber, the ion buncher I is connected between the sampling chamber and the drift chamber I, the ion buncher II is connected between the drift chamber I and the drift chamber II, the ion buncher III is connected between the drift chamber II and the buffer chamber, the ion buncher IV is connected between the buffer chamber and the collision chamber, and the quadrupole is located in the vacuum chamber. in the collision chamber; the droplet ejector is connected to the injection chamber, an ionization device is installed in the injection chamber, the side wall of the injection chamber has a small hole, the droplets ejected by the droplet ejector can enter the injection chamber through the small hole and form ion packets under the action of the ionization device, and then form an ion beam under the action of the vacuum pump group III, the injection chamber has a window, the laser emitted by the laser can enter the vacuum chamber through the window; the detector is connected to the collision chamber, the wall of the collision chamber has a through hole, the ion beam in the collision chamber can enter the detector through the through hole; the buffer chamber has a buffer gas inlet, and the drift chamber II has a drift carrier gas inlet; the ion buncher I, ion buncher III and ion buncher IV are respectively composed of twenty annular electrodes with a thickness of 0.4 mm, the interval between adjacent annular electrodes is 0.5 mm, the inner diameter of the twenty annular electrodes is linearly reduced from 45 mm to 2 mm along the positive z direction, and a 100 kilo-ohm resistor is connected in series between each annular electrode.The droplet ejector mainly includes a mass flow controller, a liquid inlet pipe, a cavity, a liquid reservoir, a driver I, a driver II and an injection port. The cavity is cylindrical, and the liquid reservoir and the injection port are provided in the cavity. The liquid reservoir is cylindrical, and the upper bottom surface and the lower bottom surface of the liquid reservoir are connected to the driver I and the driver II respectively. When the driver I and the driver II are working, the volume of the liquid reservoir can produce a slight change. The aperture range of the injection port is 40 to 400 microns, and the volume range of the liquid reservoir is 4 to 8 milliliters. The outlet end of the mass flow controller is connected to the liquid reservoir through the liquid inlet pipe, and the inlet end is connected to the sample solution storage tank; the ion buncher II has annular electrodes of different apertures arranged in sequence along the positive z direction, the thickness of the annular electrodes is 0.4 mm, and the interval between adjacent annular electrodes is 0.5 mm. The ion buncher II has five sections in sequence, namely, section I, section II, section III, section IV and section V; section I is composed of seven annular electrodes with an inner diameter of 50 mm, and section II is composed of eight annular electrodes. The inner diameters of the eight annular electrodes along the positive z direction are 45 mm, 40 mm, 35 mm, 33 mm, 30 mm, 27 mm, 24 mm and 21 mm, respectively; segment III is composed of three annular electrodes, and the inner diameters of the three annular electrodes along the positive z direction are 28 mm, 33 mm and 38 mm, respectively; segment IV is composed of five annular electrodes each having an inner diameter of 50 mm; segment V is composed of six annular electrodes, and the inner diameters of the six annular electrodes along the positive z direction are 46 mm, 4 2 mm, 38 mm, 34 mm, 30 mm and 26 mm, the ion buncher II is provided with an extraction grid, a trapping grid, an entry grid and a jet disruptor, the entry grid, the trapping grid and the extraction grid are successively arranged in segment IV along the positive direction of z, and the jet disruptor is arranged in segment I; segment I can receive a rapidly diverging free ion beam, segment II can focus the ions, the space composed of segment III, segment IV and segment V can be used to trap ions, and segment V is the final ion convergence area and has an ion outlet.

[0006] The ejection principle of the droplet ejector is as follows: in the initial state, the ejection port is parallel to the liquid surface plane of the liquid reservoir; after the driver I and the driver II are turned on, the driver vibrates at a certain frequency and moves back and forth to the outside and inside of the liquid reservoir at a certain period. In the process of the driver moving to the outside of the liquid reservoir, the volume of the liquid reservoir expands under the action of the driver, and the liquid surface at the ejection port bends into the liquid reservoir, and the degree of curvature of the liquid surface increases continuously with the expansion of the volume of the liquid reservoir; in the process of the driver moving to the inside of the liquid reservoir, the volume of the liquid reservoir decreases under the action of the driver, and the curved liquid surface is subjected to the force of the liquid in the liquid reservoir. In the process of the liquid reservoir continuing to decrease in volume under the action of the driver, an extremely fine liquid jet will be formed at the center of the curved liquid surface; in the next vibration cycle of the driver, the driver moves to the outside of the liquid reservoir, and the volume of the liquid reservoir begins to expand, pulling most of the liquid in the liquid jet that has rushed out of the ejection port plane back into the liquid reservoir, and a small part of the liquid at the tip of the liquid jet will form an extremely small droplet, so that the droplet rushes out of the liquid reservoir.

[0007] The method steps for testing using the free radical photoproduct testing device are as follows:

[0008] 1. Pass helium into drift chamber II and nitrogen into buffer chamber, with a typical flow rate of 80 SCCM;

[0009] 2. Control the mass flow controller to inject the sample solution to be tested into the reservoir, with a typical flow rate of 0.02 to 0.2 ml / min;

[0010] 3. Turn on driver I and driver II respectively. In working mode 1, the vibration frequencies of driver I and driver II are consistent, with a typical value of 0.8 to 1.5 kHz. In working mode 2, the vibration frequencies of driver I and driver II are inconsistent, with a typical value of 0.7 to 1.0 kHz for driver I and 1.3 to 1.6 kHz for driver II.

[0011] 4. The droplets ejected by the droplet ejector enter the vacuum chamber and form ion packets under the action of the ionization device, and then form an ion beam under the action of the vacuum pump group III, and the ion beam passes through the ion buncher I to the ion buncher II;

[0012] 5. respectively adjusting the potentials applied to the extraction grid, the trapping grid and the entry grid so that a portion of the ions in the ion beam are trapped in segment IV of the ion buncher II;

[0013] 6. The laser emitted by the laser enters segment IV and irradiates the ions, causing a photoreaction and producing photoproducts;

[0014] 7. Adjust the potentials applied to the extraction grid, the trapping grid and the entry grid respectively, so that the charged particles in the photoproducts are ejected from the segment V of the ion buncher II, and successively pass through the ion buncher III, the ion buncher IV and the quadrupole before finally entering the detector;

[0015] 8. Analyze the data collected by the detector to obtain relevant information about the photoreaction products of free radicals.

[0016] The beneficial effects of the present invention are:

[0017] The present invention adopts a liquid reservoir resonance method to generate and eject droplets, which can form droplets much smaller than the inner diameter of the droplet ejection port, and has no special requirements on the polarity of the solvent. It does not need to apply high voltage during operation, and is applicable to a wide variety of samples. Secondly, a buffer chamber is added to the vacuum chamber, which can minimize the loss of ion beam flow in the vacuum chamber. Furthermore, a specially designed ion buncher can perform ion introduction, trapping and ejection operations respectively, effectively reducing the volume of the device and reducing the pumping speed of the vacuum pump group. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Further explanation below in conjunction with the graphics of the present invention:

[0019] Figure 1 It is a schematic diagram of the present invention;

[0020] Figure 2 is an enlarged schematic diagram of a droplet ejector;

[0021] Figure 3 yes Figure 2 A top view of

[0022] Figure 4 is an enlarged schematic diagram of the internal cross section of the ion buncher II;

[0023] Figures 5 to 10 It is an enlarged schematic diagram of the injection port of the droplet injector and a schematic diagram of the injection principle.

[0024] In the figure, 1. laser, 2. droplet ejector, 2-1. mass flow controller, 2-2. liquid inlet pipe, 2-3. cavity, 2-4. liquid storage tank, 2-5. driver I, 2-6. driver II, 2-7. ejection port, 3. vacuum chamber, 3-1. injection chamber, 3-2. drift chamber I, 3-3. drift chamber II, 3-4. buffer chamber, 3-5. collision chamber, 4. ion buncher I, 5. ion buncher Device II, 5-1. Section I, 5-2. Section II, 5-3. Section III, 5-4. Section IV, 5-5. Section V, 5-6. Extraction grid, 5-7. Trapping grid, 5-8. Entry grid, 5-9. Jet disruptor, 6. Ion buncher III, 7. Ion buncher IV, 8. Quadrupole, 9. Detector, 10. Vacuum pump group I, 11. Vacuum pump group II, 12. Vacuum pump group III. DETAILED DESCRIPTION

[0025] like Figure 1The present invention is a schematic diagram, wherein xyz is a three-dimensional space coordinate system, and mainly comprises a laser (1), a droplet ejector (2), a vacuum chamber (3), an ion buncher I (4), an ion buncher II (5), an ion buncher III (6), an ion buncher IV (7), a quadrupole (8), a detector (9), a vacuum pump group I (10), a vacuum pump group II (11), a vacuum pump group III (12) and an ionization device, wherein the vacuum chamber (3) has a starting end and an end, and within the vacuum chamber (3), there are a sample injection chamber (3-1), a drift chamber I (3-2), a drift chamber II (3-3), a buffer chamber (3-4) and a collision chamber (3-5) in sequence from the starting end to the end, wherein The injection chamber (3-1), the buffer chamber (3-4) and the collision chamber (3-5) are respectively connected to a vacuum pump group III (12), a vacuum pump group II (11) and a vacuum pump group I (10); the ion buncher I (4), the ion buncher II (5), the ion buncher III (6), the ion buncher IV (7) and the quadrupole (8) are all located in the vacuum chamber (3); the ion buncher I (4) is connected between the injection chamber (3-1) and the drift chamber I (3-2); the ion buncher II (5) is connected between the drift chamber I (3-2) and the drift chamber II (3-3); the ion buncher III (6) is connected between the drift chamber II (3-3) and the buffer chamber (3-4); and the quadrupole (8) is connected between the drift chamber II (3-3) and the buffer chamber (3-4). 4), an ion buncher IV (7) is connected between the buffer chamber (3-4) and the collision chamber (3-5), and a quadrupole (8) is located in the collision chamber (3-5); the droplet ejector (2) is connected to the injection chamber (3-1), an ionization device is installed in the injection chamber (3-1), and a side wall of the injection chamber (3-1) has a small hole, and the droplets ejected by the droplet ejector (2) can enter the injection chamber (3-1) through the small hole and form ion packets under the action of the ionization device, and then form an ion beam under the action of the vacuum pump group III (12), and the injection chamber (3-1) has a window, and the laser light emitted by the laser (1) can enter the vacuum chamber (3-1) through the window. 3); the detector (9) is connected to the collision chamber (3-5), the cavity wall of the collision chamber (3-5) has a through hole, and the ion beam in the collision chamber (3-5) can enter the detector (9) through the through hole; the buffer chamber (3-4) has a buffer gas inlet, and the drift chamber II (3-3) has a drift carrier gas inlet; the ion buncher I (4), the ion buncher III (6) and the ion buncher IV (7) are each composed of twenty annular electrodes with a thickness of 0.4 mm, and the interval between adjacent annular electrodes is 0.5 mm. The inner diameters of the twenty annular electrodes are linearly reduced from 45 mm to 2 mm along the positive z direction, and a 100 kilo-ohm resistor is connected in series between each annular electrode.

[0026] like Figure 2 is an enlarged schematic diagram of the droplet ejector, such as Figure 3 yes Figure 2The top view of the liquid droplet ejector (2) mainly comprises a mass flow controller (2-1), a liquid inlet pipe (2-2), a cavity (2-3), a liquid reservoir (2-4), a driver I (2-5), a driver II (2-6) and an ejection port (2-7); the cavity (2-3) is cylindrical, the cavity (2-3) has the liquid reservoir (2-4) and the ejection port (2-7); the liquid reservoir (2-4) is cylindrical, and the upper bottom surface and the lower bottom surface of the liquid reservoir (2-4) are respectively connected to each other. It is connected to a driver I (2-5) and a driver II (2-6). When the driver I (2-5) and the driver II (2-6) are working, the volume of the liquid storage tank (1-4) can produce a slight change. The aperture range of the injection port (2-7) is 40 to 400 microns. The volume range of the liquid storage tank (2-4) is 4 to 8 milliliters. The outlet end of the mass flow controller (2-1) is connected to the liquid storage tank (2-4) through a liquid inlet pipe (2-2), and the inlet end is connected to a sample solution storage tank.

[0027] like Figure 4 1 is an enlarged schematic diagram of the internal cross-section of an ion buncher II, wherein the ion buncher II (5) has annular electrodes of different apertures arranged in sequence along the positive z direction, the thickness of the annular electrodes is 0.4 mm, and the interval between adjacent annular electrodes is 0.5 mm, and the ion buncher II (5) has five sections, namely, section I (5-1), section II (5-2), section III (5-3), section IV (5-4) and section V (5-5); section I (5-1) is composed of seven annular electrodes with an inner diameter of 50 mm, section II (5-2) is composed of eight annular electrodes, and the inner diameters of the eight annular electrodes are 45 mm, 40 mm, 35 mm, 33 mm, 30 mm, 27 mm, 24 mm and 21 mm respectively along the positive z direction, section III (5-3) is composed of three annular electrodes, and the inner diameters of the three annular electrodes are 28 mm, 33 mm and 38 mm respectively along the positive z direction, and section IV (5-4 ) is composed of five annular electrodes with an inner diameter of 50 mm, segment V (5-5) is composed of six annular electrodes, the inner diameters of the six annular electrodes are 46 mm, 42 mm, 38 mm, 34 mm, 30 mm and 26 mm respectively along the positive z direction, and the ion buncher II (5) has an extraction grid (5-6), a trapping grid (5-7), an entry grid (5-8) and a jet disruptor (5-9), the entry grid (5-8), the trapping grid (5 -7) and the extraction grid (5-6) are sequentially located in segment IV (5-4) along the positive z direction, and the jet disruptor (5-9) is located in segment I (5-1); segment I (5-1) can receive a rapidly diverging free ion beam, segment II (5-2) can focus the ions, and the space composed of segment III (5-3), segment IV (5-4) and segment V (5-5) can be used to trap ions, and segment V (5-5) is the final ion convergence area and has an ion outlet.

[0028] like Figures 5 to 10 It is an enlarged schematic diagram of the injection port of the droplet ejector and a schematic diagram of the injection principle. Below the injection port (2-7) is the liquid in the liquid reservoir (2-4). The arrows in the figure represent the forces inside the liquid, such as Figure 5 In the initial state, the injection port (2-7) is parallel to the liquid surface of the liquid reservoir (2-4); after the driver I (2-5) and the driver II (2-6) are turned on, the driver vibrates at a certain frequency and moves back and forth toward the outside and inside of the liquid reservoir (2-4) at a certain period. In the process of the driver moving toward the outside of the liquid reservoir (2-4), the volume of the liquid reservoir (2-4) is expanded under the action of the driver, such as Figure 6 The liquid surface at the injection port (2-7) bends toward the inside of the liquid storage tank (2-4), such as Figure 7 The degree of curvature of the liquid surface increases continuously as the volume of the liquid reservoir (2-4) increases. When the driver moves toward the inside of the liquid reservoir (2-4), the volume of the liquid reservoir (2-4) decreases under the action of the driver. Figure 8 The curved liquid surface is acted upon by the liquid in the liquid storage tank (2-4). As the volume of the liquid storage tank (2-4) continues to decrease under the action of the driver, Fig. 9 An extremely fine liquid jet will be formed at the center of the curved liquid surface; in the next vibration cycle of the driver, the driver moves toward the outside of the liquid reservoir (2-4), the volume of the liquid reservoir (2-4) begins to expand, and most of the liquid in the liquid jet that has rushed out of the plane of the injection port (2-7) is pulled back into the liquid reservoir (2-4), and a small part of the liquid at the tip of the liquid jet will form an extremely small droplet, such as Fig.10 The present invention adopts a driver whose vibration direction is perpendicular to the direction of droplet ejection, which has the advantage that the response time of droplet ejection to the opening and closing of the driver is short. In addition, two drivers that can vibrate at different frequencies and amplitudes are adopted, and droplets can be ejected in multiple vibration modes to meet different needs. In working mode one, the two drivers vibrate at the same frequency and amplitude, and in working mode two, the two drivers vibrate at different frequencies and amplitudes. The sizes of the ejected droplets are not consistent, and the smallest droplet can be smaller than the droplet ejected in working mode one. By controlling the pumping speed of the vacuum pump group, larger droplets can collide with the vacuum chamber wall, thereby leaving smaller droplets in the vacuum chamber to form an ion beam with a smaller cross-sectional area.

[0029] The free radical photoproduct testing device mainly comprises a laser (1), a droplet ejector (2), a vacuum chamber (3), an ion buncher I (4), an ion buncher II (5), an ion buncher III (6), an ion buncher IV (7), a quadrupole (8), a detector (9), a vacuum pump group I (10), a vacuum pump group II (11), a vacuum pump group III (12) and an ionization device. The vacuum chamber (3) has a starting end and an end. The vacuum chamber (3) has an injection chamber (3-1), a drift chamber I (3-2), a drift chamber II (3-3), a buffer chamber (3-4) and a collision chamber (3-5) in sequence from the starting end to the end. The injection chamber ( The vacuum chamber (3-1), the buffer chamber (3-4) and the collision chamber (3-5) are respectively connected to a vacuum pump group III (12), a vacuum pump group II (11) and a vacuum pump group I (10); the ion buncher I (4), the ion buncher II (5), the ion buncher III (6), the ion buncher IV (7) and the quadrupole (8) are all located in the vacuum chamber (3); the ion buncher I (4) is connected between the injection chamber (3-1) and the drift chamber I (3-2); the ion buncher II (5) is connected between the drift chamber I (3-2) and the drift chamber II (3-3); the ion buncher III (6) is connected between the drift chamber II (3-3) and the buffer chamber (3-4); The ion buncher IV (7) is connected between the buffer chamber (3-4) and the collision chamber (3-5), and the quadrupole (8) is located in the collision chamber (3-5); the droplet ejector (2) is connected to the injection chamber (3-1), an ionization device is installed in the injection chamber (3-1), and the side wall of the injection chamber (3-1) has a small hole, and the droplets ejected by the droplet ejector (2) can enter the injection chamber (3-1) through the small hole and form ion packets under the action of the ionization device, and then form an ion beam under the action of the vacuum pump group III (12), and the injection chamber (3-1) has a window, and the laser light emitted by the laser (1) can enter the vacuum chamber (3) through the window. The detector (9) is connected to the collision chamber (3-5), the wall of the collision chamber (3-5) has a through hole, and the ion beam in the collision chamber (3-5) can enter the detector (9) through the through hole; the buffer chamber (3-4) has a buffer gas inlet, and the drift chamber II (3-3) has a drift carrier gas inlet; the ion buncher I (4), the ion buncher III (6) and the ion buncher IV (7) are each composed of twenty annular electrodes with a thickness of 0.4 mm, and the interval between adjacent annular electrodes is 0.5 mm. The inner diameters of the twenty annular electrodes are linearly reduced from 45 mm to 2 mm along the positive z direction, and a 100 kilo-ohm resistor is connected in series between each annular electrode.The droplet ejector (2) mainly comprises a mass flow controller (2-1), a liquid inlet pipe (2-2), a cavity (2-3), a liquid reservoir (2-4), a driver I (2-5), a driver II (2-6) and an ejection port (2-7); the cavity (2-3) is cylindrical, the liquid reservoir (2-4) and the ejection port (2-7) are arranged in the cavity (2-3); the liquid reservoir (2-4) is cylindrical, the upper bottom surface and the lower bottom surface of the liquid reservoir (2-4) are respectively connected to the driver I (2-5) and the driver II (2-6); when the driver I (2-5) and the driver II (2-6) are working, the volume of the liquid reservoir (1-4) can produce a slight change, and the ejection port (2-7) is increased. The aperture of the port (2-7) is in the range of 40 to 400 microns, the volume of the liquid reservoir (2-4) is in the range of 4 to 8 milliliters, the outlet of the mass flow controller (2-1) is connected to the liquid reservoir (2-4) through the liquid inlet pipe (2-2), and the inlet is connected to the sample solution storage tank; the ion buncher II (5) has annular electrodes with different apertures arranged in sequence along the positive z direction, the thickness of the annular electrodes is 0.4 mm, and the interval between adjacent annular electrodes is 0.5 mm, the ion buncher II (5) has five sections in sequence, namely, section I (5-1), section II (5-2), section III (5-3), section IV (5-4) and section V (5-5); section I (5-1) consists of seven inner The inner diameters of the eight annular electrodes along the positive z direction are 45 mm, 40 mm, 35 mm, 33 mm, 30 mm, 27 mm, 24 mm and 21 mm, respectively; the segment III (5-3) is composed of three annular electrodes, the inner diameters of the three annular electrodes along the positive z direction are 28 mm, 33 mm and 38 mm, respectively; the segment IV (5-4) is composed of five annular electrodes, each of which has an inner diameter of 50 mm; the segment V (5-5) is composed of six annular electrodes, the inner diameters of the six annular electrodes along the positive z direction are 46 mm, 42 mm, 38 mm, 34 mm, 30 mm and 21 mm, respectively. 26 mm, the ion buncher II (5) has an extraction grid (5-6), a trapping grid (5-7), an entry grid (5-8) and a jet disruptor (5-9), the entry grid (5-8), the trapping grid (5-7) and the extraction grid (5-6) are successively located in the segment IV (5-4) along the positive z direction, and the jet disruptor (5-9) is located in the segment I (5-1); the segment I (5-1) can receive a rapidly diverging free ion beam, the segment II (5-2) can focus the ions, the space composed of the segment III (5-3), the segment IV (5-4) and the segment V (5-5) can be used to trap ions, and the segment V (5-5) is the final ion convergence area and has an ion outlet.

[0030] The ejection principle of the droplet ejector is as follows: in the initial state, the ejection port (2-7) is parallel to the liquid surface plane of the liquid reservoir (2-4); after the driver I (2-5) and the driver II (2-6) are turned on, the driver vibrates at a certain frequency and moves back and forth toward the outside and inside of the liquid reservoir (2-4) at a certain period; in the process of the driver moving toward the outside of the liquid reservoir (2-4), the volume of the liquid reservoir (2-4) is expanded under the action of the driver, and the liquid surface at the ejection port (2-7) is bent toward the inside of the liquid reservoir (2-4), and the degree of the liquid surface bending increases continuously as the volume of the liquid reservoir (2-4) expands; in the process of the driver moving toward the inside of the liquid reservoir (2-4), the liquid reservoir (2-4) is moved back and forth to the inside of the liquid reservoir (2-4). The volume of the reservoir (2-4) decreases under the action of the driver, and the curved liquid surface is subjected to the force of the liquid in the reservoir (2-4). As the volume of the reservoir (2-4) continues to decrease under the action of the driver, an extremely fine liquid jet is formed at the center of the curved liquid surface. In the next vibration cycle of the driver, the driver moves toward the outside of the reservoir (2-4), and the volume of the reservoir (2-4) begins to expand, pulling most of the liquid in the liquid jet that has rushed out of the plane of the injection port (2-7) back into the reservoir (2-4), and a small part of the liquid at the tip of the liquid jet forms an extremely small droplet, so that the droplet rushes out of the reservoir (2-4).

[0031] The present invention adopts a liquid reservoir resonance method to generate and eject droplets. The vibration direction of the driver is perpendicular to the direction of droplet ejection, which can form droplets of smaller size, and has no special requirements for solvents and no need to apply high voltage. It is applicable to a wide variety of free radical samples. Secondly, the buffer chamber can reduce the loss of ion beam in the vacuum chamber. Furthermore, the specially designed ion buncher is small in size and can reduce the pumping speed of the vacuum pump group.

Claims

1. A free radical photoproduct testing device, comprising a laser (1), a droplet ejector (2), a vacuum chamber (3), an ion buncher I (4), an ion buncher II (5), an ion buncher III (6), an ion buncher IV (7), a quadrupole (8), a detector (9), a vacuum pump group I (10), a vacuum pump group II (11), a vacuum pump group III (12) and an ionization device, wherein xyz is a three-dimensional space coordinate system, the vacuum chamber (3) has a starting end and an end, and in the vacuum chamber (3), there are a sample injection chamber (3-1), a drift chamber I (3-2), a drift chamber II (3-3), a buffer chamber (3-4) and a collision chamber (3-5) in sequence from the starting end to the end. 5), the injection chamber (3-1), the buffer chamber (3-4) and the collision chamber (3-5) are respectively connected to a vacuum pump group III (12), a vacuum pump group II (11) and a vacuum pump group I (10); the ion buncher I (4), the ion buncher II (5), the ion buncher III (6), the ion buncher IV (7) and the quadrupole (8) are all located in the vacuum chamber (3), the ion buncher I (4) is connected between the injection chamber (3-1) and the drift chamber I (3-2), the ion buncher II (5) is connected between the drift chamber I (3-2) and the drift chamber II (3-3), the ion buncher III (6) is connected between the drift chamber II (3-3) and the buffer chamber (3-4), an ion buncher IV (7) is connected between the buffer chamber (3-4) and the collision chamber (3-5), and a quadrupole (8) is located in the collision chamber (3-5); the droplet ejector (2) is connected to the injection chamber (3-1), an ionization device is installed in the injection chamber (3-1), and a side wall of the injection chamber (3-1) has a small hole, and the droplets ejected by the droplet ejector (2) can enter the injection chamber (3-1) through the small hole and form ion packets under the action of the ionization device, and then form an ion beam under the action of the vacuum pump group III (12), and the injection chamber (3-1) has a window, and the laser light emitted by the laser (1) can enter the vacuum chamber through the window (3); the detector (9) is connected to the collision chamber (3-5), the cavity wall of the collision chamber (3-5) has a through hole, and the ion beam in the collision chamber (3-5) can enter the detector (9) through the through hole; the buffer chamber (3-4) has a buffer gas inlet, and the drift chamber II (3-3) has a drift carrier gas inlet; the ion buncher I (4), the ion buncher III (6) and the ion buncher IV (7) are each composed of twenty annular electrodes with a thickness of 0.4 mm, and the interval between adjacent annular electrodes is 0.5 mm. The inner diameter of the twenty annular electrodes is linearly reduced from 45 mm to 2 mm along the positive z direction, and a 100 kilo-ohm resistor is connected in series between each annular electrode. Its characteristics are: The droplet ejector (2) mainly comprises a mass flow controller (2-1), a liquid inlet pipe (2-2), a cavity (2-3), a liquid reservoir (2-4), a driver I (2-5), a driver II (2-6) and an ejection port (2-7). The cavity (2-3) is cylindrical, and the liquid reservoir (2-4) and the ejection port (2-7) are arranged in the cavity (2-3). The liquid reservoir (2-4) is cylindrical, and the upper bottom surface and the lower bottom surface of the liquid reservoir (2-4) are respectively connected to the driver I (2-5) and the driver II (2-6). When the driver I (2-5) and the driver II (2-6) are working, the volume of the liquid reservoir (1-4) can produce a slight change, and the ejection port (2-7) is arranged in the cavity (2-3). The aperture range of the mass flow controller (2-1) is 40 to 400 microns, the volume range of the liquid reservoir (2-4) is 4 to 8 milliliters, the outlet end of the mass flow controller (2-1) is connected to the liquid reservoir (2-4) through the liquid inlet pipe (2-2), and the inlet end is connected to the sample solution storage tank; the ion buncher II (5) has annular electrodes with different apertures arranged in sequence along the positive z direction, the thickness of the annular electrodes is 0.4 mm, and the interval between adjacent annular electrodes is 0.5 mm, the ion buncher II (5) has five sections in sequence, namely, section I (5-1), section II (5-2), section III (5-3), section IV (5-4) and section V (5-5); section I (5-1) is composed of seven sections with inner diameters of The inner diameters of the eight annular electrodes along the positive z direction are 45 mm, 40 mm, 35 mm, 33 mm, 30 mm, 27 mm, 24 mm and 21 mm, respectively; the inner diameters of the three annular electrodes along the positive z direction are 28 mm, 33 mm and 38 mm, respectively; the inner diameters of the six annular electrodes along the positive z direction are 50 mm, 5-2 are composed of eight annular electrodes, and the inner diameters of the eight annular electrodes along the positive z direction are 45 mm, 40 mm, 35 mm, 33 mm, 30 mm, 27 mm, 24 mm and 21 mm, respectively; the inner diameters of the three annular electrodes along the positive z direction are 28 mm, 33 mm and 38 mm, respectively; the inner diameters of the six annular electrodes along the positive z direction are 50 mm, 5-3 are composed of three annular electrodes, and the inner diameters of the three annular electrodes along the positive z direction are 28 mm, 33 mm and 38 mm, respectively; the inner diameters of the six annular electrodes along the positive z direction are 50 mm, 5-4 are composed of five annular electrodes, and the inner diameters of the six annular electrodes along the positive z direction are 46 mm, 42 mm, 38 mm, 34 mm, 30 mm, respectively m and 26 mm, the ion buncher II (5) has an extraction grid (5-6), a trapping grid (5-7), an entry grid (5-8) and a jet disruptor (5-9), the entry grid (5-8), the trapping grid (5-7) and the extraction grid (5-6) are sequentially located in the segment IV (5-4) along the positive z direction, and the jet disruptor (5-9) is located in the segment I (5-1); the segment I (5-1) can receive a fast diverging free ion beam, the segment II (5-2) can focus the ions, the space composed of the segment III (5-3), the segment IV (5-4) and the segment V (5-5) can be used to trap the ions, and the segment V (5-5) is the final ion convergence area and has an ion outlet; The ejection principle of the droplet ejector: in the initial state, the ejection port is parallel to the liquid surface plane of the liquid reservoir; after turning on the driver I and the driver II, the driver vibrates at a certain frequency and moves back and forth to the outside and inside of the liquid reservoir at a certain period. In the process of the driver moving to the outside of the liquid reservoir, the volume of the liquid reservoir expands under the action of the driver, and the liquid surface at the ejection port bends into the liquid reservoir. The degree of curvature of the liquid surface increases continuously with the expansion of the volume of the liquid reservoir; in the process of the driver moving to the inside of the liquid reservoir, the volume of the liquid reservoir decreases under the action of the driver, and the curved liquid surface is subjected to the force of the liquid in the liquid reservoir. In the process of the liquid reservoir volume continuing to decrease under the action of the driver, an extremely fine liquid jet will be formed at the center of the curved liquid surface; In the next vibration cycle of the driver, the driver moves toward the outside of the liquid reservoir, and the volume of the liquid reservoir begins to expand, pulling most of the liquid in the liquid jet that has rushed out of the injection port plane back into the liquid reservoir, and a small part of the liquid at the tip of the liquid jet will form a tiny droplet, so that the droplet rushes out of the liquid reservoir.

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