A device for an americium-241 desorption ionization ion source

Abstract

The application discloses an ion source device for desorption of americium 241, and relates to the technical field of ion sources.The ion source device mainly comprises americium 241, a clamping device for the americium 241, an R-axis rotating platform and a sample stage.The americium 241 is installed on the clamping device for the americium 241, and the clamping device is installed on the R-axis rotating platform.A glass slide coated with a sample is installed on the sample stage, and the sample stage and the R-axis rotating platform are installed on two XYZ-axis displacement platforms, respectively, and the two XYZ-axis displacement platforms are adjusted to move in the X, Y and Z directions, respectively.The alpha particles generated by the americium 241 decay generate a series of plasmas in the air and are injected into the surface of the sample, so that the molecules on the surface of the sample are ionized and desorbed, and the ions enter a mass spectrometer through a sample inlet for detection.The relative positions of the americium 241, the sample stage and the sample inlet are adjusted, so that the mass spectrometer obtains the best ion signal, and the operation is safe and simple, and the common molecules can be rapidly detected.

Description

Technical Field

[0001] This invention relates to the field of ion source technology, and in particular to an americium-241 desorption ionization ion source. Background Technology

[0002] The Americium-241 desorption ionization source (AmDI) uses americium-241, which has a half-life of 432.2 years. During its decay, it produces neptunium atoms, alpha particles, and trace amounts of gamma rays. This ion source primarily utilizes the alpha particles produced by the decay of americium-241. An alpha particle consists of two protons and two neutrons and has a kinetic energy of approximately 5.5 MeV. During collisions with molecules in the air, the alpha particle ionizes the molecules by consuming its own energy, producing approximately 1.4 × 10⁻⁶ gamma rays in the air. 5 Each ion pair contains numerous electrons, cations, and anions. The plasma, formed by alpha particles and containing electrons, cations, and anions, further interacts with the analyte, achieving ionization and desorption. This characteristic is highly suitable for use in ion source devices at the front end of a mass spectrometer.

[0003] Currently, most ion sources require energy sources such as high voltage, high temperature, laser, ultrasound, and microwave in operation, which pose certain risks to some extent. At the same time, the devices are large in size, not easy to carry, and have complex components, resulting in high purchase and maintenance costs. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a simple, low-cost, and highly safe mass spectrometry ionization device that can operate at room temperature and pressure. To this end, the technical solution of this invention is as follows:

[0005] An americium-241 desorption ionization source device mainly includes: an americium-241, a clamping device for the americium-241, an R-axis rotating platform, and a sample stage. The americium-241 is mounted on the clamping device, which is mounted on the R-axis rotating platform. A glass slide coated with a sample is mounted on the stage. The stage and the R-axis rotating platform are respectively mounted on two XYZ-axis displacement platforms, which can be moved and adjusted in the X, Y, and Z directions, respectively.

[0006] Furthermore, the clamping device consists of an americium 241 fixing device and a clamp for the fixing device. The americium 241 fixing device consists of a conical head and a cylindrical body. The joint between the cylinder and the cone has a groove that matches the volume of the americium 241. There is a cylindrical tube in the center of the cylinder, and there is an M6 threaded hole inside the cylindrical tube. After the americium 241 is inserted into the groove, the M6 ​​screw is inserted into the threaded hole to the top so that the americium 241 is tightly attached to the inner wall of the groove.

[0007] Furthermore, the Americium 241 fixing device in the clamping device is connected to the R-axis rotating platform through a clamp. The clamp has two clamping arms, and the middle part of the two clamping arms is recessed inward into a semi-circle, so that a circular cavity is formed in the middle of the two clamping arms. The Americium 241 fixing device passes through the circular hole in the middle of the clamp. M3 screws are used at the front end of the two clamping arms of the clamp, passing through the corresponding M3 threaded holes. Tightening the M3 screws brings the two sides of the clamp closer together and clamps the Americium 241 fixing device.

[0008] Furthermore, the surface of the R-axis rotary platform has M3 threaded holes that are adapted to the clamping device fixture base. The fixture is installed on the R-axis rotary platform by inserting an M3 screw into the threaded hole.

[0009] Furthermore, the R-axis rotary platform can rotate 360° and is mounted on the first XYZ axis moving platform.

[0010] Furthermore, a glass slide coated with the sample is mounted on a stage, with metal clips on both sides of the stage for clamping the glass slide. The stage is mounted on a second XYZ axis moving platform.

[0011] Furthermore, the first XYZ axis moving platform and the second XYZ axis moving platform enable the adjustment of the position of the R-axis rotary platform and the stage mounted on them in the X, Y and Z directions.

[0012] This invention inserts Americium-241 from the side into the inner groove of the Americium-241 fixing device of the clamping device. The clamping device with Americium-241 is mounted on an R-axis rotation platform, which is then fixed to a first XYZ-axis displacement platform. The orientation of Americium-241 is adjusted via the R-axis rotation platform, and its horizontal position and vertical height are adjusted via the first XYZ-axis displacement platform. The sample is prepared on a glass slide and fixed to the stage. The stage is fixed to a second XYZ-axis displacement platform, and the sample position is adjusted via the second XYZ-axis displacement platform to be between the mass spectrometer inlet and the Americium-241. The relative positions of the Americium-241, the glass slide, and the inlet are adjusted to obtain the optimal ion signal for the mass spectrometer. The alpha particles generated by the decay of Americium-241 produce a series of electrons, cations, and anions in the air. These plasmas are injected into the sample surface, ionizing and desorbing molecules on the sample surface. These ions then enter the mass spectrometer through the inlet for detection. This achieves the goal of safe and simple operation, enabling rapid detection of common molecules.

[0013] The americium-241 described in this device is a common type of nuclear waste, generally existing in the form of americium dioxide. The americium-241 used in this device is approximately 0.2 mm thick and 2 mm in diameter, covered by a 2-micrometer-thick gold coating. During its decay, americium-241 produces neptunium atoms, alpha particles, and trace amounts of gamma rays.

[0014] Compared with other ion source devices, the Americium-241 plasma desorption ion source device described in this invention has the following characteristics:

[0015] This device requires no external voltage or vacuum environment, achieving ionization and detection of molecules at room temperature and atmospheric pressure. It boasts high safety; the required Americium-241 is commonly used in smoke detectors, and within safe operating limits, the released alpha particles pose negligible harm to humans. The device is easy to assemble, cost-effective, and convenient to disassemble, maintain, and carry. Furthermore, it offers rapid detection, ionizing the target analyte within seconds. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the clamping end of the Americium 241 desorption ionization source device of the present invention;

[0017] Figure 2 This is a schematic diagram of the loading end of the Americium-241 desorption ionization source device of the present invention;

[0018] In the figure: 101, First XYZ axis moving platform; 102, Second XYZ axis moving platform; 201, First platform support; 202, Second platform support; 3, R axis moving platform; 4, Connecting plate; 5, Americium 241 fixing device; 6, Clamp; 7, Clamping screw; 8, Groove; 9, Fixing plate; 10, Fixing platform; 11, Stage; 12, Clamping piece; 13, Fastening screw. Detailed Implementation

[0019] The following describes in further detail an Americium-241 desorption ionization source device with reference to the accompanying drawings.

[0020] The Americium 241 desorption ionization source device of the present invention includes a clamping end and a carrying end that cooperate with each other, wherein the clamping end is as shown in the attached figure. Figure 1 As shown, it includes a first XYZ axis moving platform 101, on which a first platform bracket 201 is provided. A connecting plate 4 is provided on the side of the first platform bracket 201. An R-axis moving platform 3 is provided on the outside of the connecting plate 4. A clamping device for fixing the americium 241 is provided on the R-axis moving platform 3.

[0021] The clamping device consists of two parts: an americium 241 fixing device 5 and a clamp 6 for the fixing device. The americium 241 fixing device consists of a conical head and a cylindrical body. At the junction of the cylinder and the cone, there is a groove 8 that fits the volume of the americium 241. The americium 241 is placed in the groove 8, with its center on the vertical line of the cone. A cylindrical tube exists at the center of the cylinder, with its front end at the top of the cylinder body and its end coinciding with the center of the groove 8. An M6 threaded hole is located within the cylindrical tube in the middle of the cylinder. An M6 screw is vertically inserted into the top of the cylinder, and after being screwed in, it presses against the americium 241, making the americium 241 tightly adhere to the bottom of the conical part of the americium 241 fixing device. The clamp 6 of the fixing device includes a base and two clamping arms on the base. The middle part of each clamping arm is recessed inward into a semi-circle, forming a circular cavity in the middle of the two clamping arms for clamping the Americium 241 fixing device 5 within the cavity. The front ends of the two clamping arms of the clamp 6 are provided with M3 threaded holes that pass through the two clamping arms. The clamp 6 clamps the Americium 241 fixing device 5 from the outside. An M3 screw passes through the M3 threaded hole on one side of the clamping arm and is inserted into the M3 threaded hole on the other side. Tightening the M3 screw clamps the Americium 241 fixing device 5 securely. The tightness of the clamp 6 is adjusted by the degree to which the M3 screw is inserted into the threaded hole. This clamping device is fixed to the R-axis rotary platform 3 with an M3 screw.

[0022] See appendix Figure 2 The loading end of the present invention includes a second XYZ axis moving platform 102, on which a second platform bracket 202 is provided. A fixing plate 9 is provided on the side of the second platform bracket 202. The bottom of the fixing plate 9 extends outward to form a horizontal fixing platform 10, on which a loading stage 11 is provided. The loading stage 11 is a tuning fork structure with a recess in the middle, and metal clips 12 are provided at both ends. The two metal clips 12 are fixed to the loading stage 11 by fastening screws 13 for clamping glass slides.

[0023] The first XYZ axis moving platform 101 and the second XYZ axis moving platform 102 of this invention can be adjusted in the X, Y, and Z directions. The R-axis rotating platform can rotate 360°. The operator can adjust the position of the R-axis rotating platform 3 and the stage 11 in the XYZ directions by adjusting the two XYZ axis moving platforms. The orientation of the clamping device connected to the R-axis rotating platform 3 can be changed by adjusting the angle of the R-axis rotating platform 3, thereby adjusting the position of the americium 241 fixing device 5 of the clamping device and the americium 241 on the americium 241 fixing device 5, as well as the position of the sample-coated glass slide. The sample-coated glass slide is mounted on the stage, and the ion signal of the sample is captured by the provided mass spectrometer. When the americium 241, the stage 11, and the mass spectrometer inlet are in the appropriate relative positions, the mass spectrometer will obtain a clear and stable ion signal.

[0024] This device can continuously adjust the angle of the americium-241 and its relative position to the sample based on the sample's properties, thereby adjusting the ionization effect on the sample. After the sample is ionized, the position of the mass spectrometer inlet is continuously adjusted to ensure that the ionized molecules are effectively captured by the mass spectrometer inlet.

[0025] The above description is an example of an Americium-241 desorption ionization source. Any modifications, additions, or substitutions made by those skilled in the art within the scope of this description should fall within the protection scope of this invention.

Claims

1. An Americium-241 desorption ionization source device, characterized in that: The device mainly includes: an americium 241, a clamping device for the americium 241, an R-axis rotating platform, and a sample stage. The americium 241 is mounted on the clamping device, which is mounted on the R-axis rotating platform. A glass slide coated with the sample is mounted on the stage. The stage and the R-axis rotating platform are respectively mounted on two XYZ axis displacement platforms. The two XYZ axis movement platforms can move and adjust in the X, Y, and Z directions, respectively.

2. The americium-241 desorption ionization source device according to claim 1, characterized in that: The clamping device consists of an americium 241 fixing device and a clamp for the fixing device. The americium 241 fixing device consists of a conical head and a cylindrical body. The joint between the cylinder and the cone has a groove that matches the volume of the americium 241. There is a cylindrical tube in the center of the cylinder, and there is an M6 threaded hole inside the cylindrical tube. After the americium 241 is inserted into the groove, the M6 ​​screw is inserted into the threaded hole to the top so that the americium 241 is tightly attached to the inner wall of the groove.

3. The americium-241 desorption ionization source device according to claim 2, characterized in that: The Americium 241 fixing device in the clamping device is connected to the R-axis rotating platform through a clamp. The clamp has two clamping arms, and the middle part of the two clamping arms is recessed into a semi-circle, so that a circular cavity is formed in the middle of the two clamping arms. The Americium 241 fixing device passes through the circular hole in the middle of the clamp. M3 screws are used at the front end of the two clamping arms of the clamp, passing through the corresponding M3 threaded holes. Tightening the M3 screws brings the two sides of the clamp closer together and clamps the Americium 241 fixing device.

4. The americium-241 desorption ionization source device according to claim 3, characterized in that: The surface of the R-axis rotary platform has M3 threaded holes that are adapted to the fixture base of the clamping device. The fixture is installed on the R-axis rotary platform by inserting an M3 screw into the threaded hole.

5. The americium-241 desorption ionization source device according to claim 4, characterized in that: The R-axis rotary platform can rotate 360° and is mounted on the first XYZ axis moving platform.

6. The americium-241 desorption ionization source device according to claim 1, characterized in that: A glass slide coated with the sample is mounted on a stage. Metal clips are located on both sides of the stage to clamp the glass slide. The stage is mounted on a second XYZ axis moving platform.

7. An Americium-241 desorption ionization source device according to claim 5 or 6, characterized in that: The first XYZ axis moving platform and the second XYZ axis moving platform enable the adjustment of the position of the R-axis rotary platform and the stage mounted on them in the X, Y and Z directions.

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