Hydrogen and helium isotope online analysis device and method based on flight time

Abstract

The invention relates to the technical field of isotope detection, in particular to a hydrogen and helium isotope online analysis device based on flight time, which comprises a cavity, a laser, and a rack, an extraction electrode, a film, a slit and a detector which are arranged in the cavity, and the outside of the cavity is connected with a vacuum pump to enable the cavity to be in vacuum; the laser ionizes hydrogen and helium isotopes on the rack into hydrogen positive ions and helium positive ions by using pulse laser through an incidence window arranged on the cavity, and takes the emission time of the pulse laser as a starting time signal of the flight time detection system; hydrogen positive ions and helium positive ions are led out and accelerated to proper energy through an electric field between the rack and the extraction electrode, the hydrogen positive ions and the helium positive ions penetrate through the thin film, pass through the slit and are measured by the detector, and a stop time signal of the flight time detection system is given; a flight time spectrum is obtained by using a flight time detection system through a time amplitude conversion system, and online analysis of the hydrogen and helium isotope content is realized. The measurement is fast.

Description

Technical Field

[0001] The present invention relates to the technical field of isotope detection, and in particular to a hydrogen and helium isotope online analysis device and method based on time of flight. Background Art

[0002] Hydrogen isotopes H-1, D-2, T-3 and helium isotopes He-3, He-4 are important nuclides for nuclear fusion, nuclear materials and nuclear environment analysis. The development and application of hydrogen and helium isotope online analysis technology is of great significance to the above research. The present invention is an online analysis device for hydrogen and helium isotope spectrum based on time of flight.

[0003] The flight time (t) of the ions is determined by the following formula:

[0004]

[0005] Where d is the flight distance, M is the mass of the ion, and E is the energy of the ion. It can be seen that the mass and energy of the ion are related to the flight time of the ion. For ions of the same energy, nuclides of different masses have different flight times at the same distance, so the time-of-flight method can be used to distinguish nuclides of different masses. However, for T-3 and He-3 among hydrogen and helium isotopes, their masses are very close, and the mass difference is less than one hundred thousandth, so the time-of-flight method cannot be used directly to analyze hydrogen and helium isotopes. At the same time 3 He is a decay product of T, and materials containing tritium must contain He-3. Therefore, this is a difficult point in the analysis of hydrogen and helium isotopes. The present invention invents an analysis technology based on thin film energy absorption combined with time-of-flight measurement, which uses the different energy losses of T-3 and He-3 after passing through the thin film to make the flight time of the two different at the same distance, thereby achieving the identification of T-3 and He-3. At the same time, H-1, D-2 and He-4 can be analyzed using flight time due to their different masses, so the time-of-flight technology can be used to achieve the analysis of hydrogen and helium isotopes. Summary of the invention

[0006] In view of the problems existing in the prior art, the purpose of the present invention is to provide a hydrogen and helium isotope online analysis device and method based on time of flight to meet the needs of rapid online analysis of hydrogen and helium isotopes in fields such as fusion reactor research. The present invention is based on technical innovation combining thin film energy absorption and time of flight technology, solves the technical difficulties of online analysis of hydrogen and helium isotopes, and provides high-quality analysis devices and technologies for applications in the nuclear industry and the environment.

[0007] In order to achieve the above-mentioned object of the invention, the technical solution of the present invention is as follows:

[0008] A hydrogen and helium isotope online analysis device based on time of flight comprises a cavity, a laser, a stage, an extraction electrode, a film, a slit and a detector arranged in the cavity. The cavity is connected to a vacuum pump outside to make the cavity in a vacuum state. The laser ionizes hydrogen and helium isotopes on the stage into hydrogen positive ions and helium positive ions by using pulsed laser to pass through an incident window arranged on the cavity, and uses the pulsed laser emission time as a start time signal of a time of flight detection system. The hydrogen positive ions and helium positive ions are extracted and accelerated to appropriate energy through the electric field between the stage and the extraction electrode. The hydrogen positive ions and helium positive ions pass through the film and the slit, and are measured by the detector and a stop time signal of the time of flight detection system is given. The time of flight detection system is used to obtain a time of flight spectrum through a time amplitude conversion system to realize online analysis of the hydrogen and helium isotope contents.

[0009] Furthermore, the stand, lead-out electrode, film, slit and detector are sequentially arranged in the cavity along the axis.

[0010] Furthermore, the incident window is made of MgF 2 Or borosilicate glass can enhance the transmittance of laser.

[0011] Furthermore, the bench voltage is 48-50 kV, and the extraction electrode voltage is 0V.

[0012] Furthermore, a grid-shaped pre-extraction electrode is arranged between the stage and the extraction electrode and close to the stage. The pre-extraction electrode voltage is 1 kV lower than the stage voltage. The extraction and focusing of positive ions are achieved by voltage matching between the pre-extraction electrode and the extraction electrode.

[0013] Furthermore, if the hydrogen and helium isotopes are in the form of gas, they flow into the stand through a quartz microporous tube.

[0014] Furthermore, the electric field between the stage and the extraction electrode accelerates the hydrogen positive ions and the helium positive ions to an energy of 48 to 50 KeV.

[0015] Furthermore, the film is a silicon nitride film.

[0016] Furthermore, the silicon nitride film has a thickness of 30 nm.

[0017] Furthermore, the slit is circular and has a diameter of 4 to 6 mm.

[0018] Furthermore, the distance between the detector and the film is 50 cm.

[0019] Furthermore, the detector is a microchannel plate.

[0020] Furthermore, the above device is used to perform a method for online analysis of hydrogen and helium isotopes based on time of flight, comprising the following steps:

[0021] Step 1, placing a sample containing hydrogen and helium isotopes on a stand;

[0022] Step 2, using a pulsed laser to act on a sample containing hydrogen and helium isotopes and ionize the sample into hydrogen positive ions and helium positive ions, and using the pulsed laser emission time as a start time signal of a time-of-flight detection system;

[0023] Step 3, using the electric field between the gantry and the extraction electrode to extract the positive hydrogen ions and the positive helium ions and accelerate them to appropriate energy;

[0024] Step 4, using the film as an energy absorption membrane to allow hydrogen ions and helium ions to pass through the film;

[0025] Step 5: In order to eliminate the interference of stray particles and improve the time resolution, the positive hydrogen ions and the positive helium ions are allowed to pass through the slit;

[0026] Step 6, a detector at an appropriate distance from the film is used to measure and provide a stop time signal of the time-of-flight detection system;

[0027] Step 7, using the time-of-flight detection system to obtain a time-of-flight spectrum through a time-amplitude conversion system, and realizing online analysis of the hydrogen and helium isotope contents by using the different flight times of hydrogen and helium isotopes in the time-of-flight spectrum.

[0028] Further, in step 1, a solid sample containing hydrogen and helium isotopes is placed directly on the stand.

[0029] Further, in step 1, a gas sample containing hydrogen and helium isotopes flows into the stand through a quartz microbore tube.

[0030] Furthermore, in step 1, the bench voltage is 48-50 kV.

[0031] Furthermore, in step 3, the extraction electrode voltage is 0V, and the hydrogen cations and helium cations are accelerated to an energy of 48 to 50 KeV.

[0032] Furthermore, in step 4, the film is a silicon nitride film with a thickness of 30 nm.

[0033] Furthermore, in step 6, the distance between the detector and the film is 50 cm.

[0034] Further, in step 6, the detector is a microchannel plate.

[0035] The beneficial effects of the present invention are as follows:

[0036] 1. Simple structure: This set of detection equipment has a simple structure. Compared with other hydrogen and helium analysis equipment, the present invention does not require expensive magnets and complex measurement systems. It can achieve analysis and measurement using only the time-of-flight method. At the same time, this method also has the advantage of being able to analyze solid and gas samples.

[0037] 2. Fast measurement: The present invention can realize online measurement, meeting the demand for fast online analysis of gas samples.

[0038] 3. In-situ analysis of solid samples: This technology combined with laser ionization technology can realize micro-area scanning analysis of solid samples, that is, it can realize distribution measurement at different positions and depths, and obtain the position and depth distribution information of hydrogen and helium isotopes in the sample, which can meet a wider range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic diagram of the structure of a hydrogen and helium isotope online analysis device based on time of flight. DETAILED DESCRIPTION

[0040] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0041] The present invention provides a time-of-flight-based hydrogen and helium isotope online analysis device, which includes a cavity, a laser, and a stand, an extraction electrode, a film, a slit, and a detector arranged in the cavity. The cavity is externally connected to a vacuum pump to make the cavity in a vacuum; the laser uses pulsed laser to pass through an incident window arranged on the cavity to ionize hydrogen and helium isotopes on the stand into hydrogen positive ions and helium positive ions, and uses the pulsed laser emission time as the starting time signal of the time-of-flight detection system, and extracts hydrogen positive ions and helium positive ions through the electric field between the stand and the extraction electrode and accelerates them to appropriate energy. The hydrogen positive ions and helium positive ions pass through the film and the slit, and are measured by the detector and give a stop time signal of the time-of-flight detection system; the time-of-flight detection system is used to obtain a time-of-flight spectrum through a time-amplitude conversion system to achieve online analysis of the hydrogen and helium isotope contents. The specific technical scheme is as follows:

[0042] The invention discloses a hydrogen and helium isotope online analysis device based on time of flight. Figure 1 The structure shown in the figure is composed of laser, stand, extraction electrode, film, slit, detector and other parts. The whole part is in the vacuum chamber, and the external vacuum pump is connected to make the system in a vacuum environment. The sample can be either a solid sample or a gas sample (the gas sample is ejected through the microporous tube).

[0043] The stand, the lead-out electrode, the film, the slit and the detector are sequentially arranged in the cavity along the axis.

[0044] A sample containing hydrogen and helium isotopes is placed on a high-voltage stand with a voltage of about +50KV. The laser uses pulsed laser to act on the sample through the incident window set on the cavity and ionize the sample into hydrogen positive ions and helium positive ions. At the same time, the pulsed laser emission time is used as the starting time signal of the time-of-flight detection system.

[0045] Using MgF 2 Or borosilicate glass as the laser incident window can enhance the laser transmittance.

[0046] The stand on which the sample is placed is an insulating stand that can withstand a voltage of 50KV. A grid-shaped pre-lead electrode is provided between the sample and the lead-out electrode, close to the sample. The voltage of the pre-lead-out electrode is about 1KV lower than the positive high voltage of the stand.

[0047] The extraction electrode adopts an "eight" shaped structure, and the electrodes gradually approach each other along the direction of ion movement. The voltage of the extraction electrode is set to 0V, and the potential difference between the high-voltage stand containing the hydrogen and helium isotope samples and the extraction electrode is used to extract the positive hydrogen ions and helium ions generated by ionization and accelerate them to an energy of about 50KeV. By matching the voltage between the pre-extraction electrode and the extraction electrode, the positive ions can be accelerated and extracted on the one hand, and focused on the other hand.

[0048] A silicon nitride film with very good thickness uniformity is used as an energy absorption film. Considering the requirements for ion energy loss, the thickness of the silicon nitride film used is 30nm. The accelerated hydrogen ions and helium ions pass through the 30nm thick silicon nitride film. Based on the different energy loss rates of hydrogen isotopes and helium isotopes penetrating the film, H, D, T and helium isotopes He-3 and He-4 have different residual energies. The most critical thing is that the energy difference between tritium and He-3 when passing through the silicon nitride film reaches 4KeV (the residual energy of He-3 is 42KeV, and the residual energy of T is 46KeV), so that the energy difference between tritium and He-3 at this time reaches about 9%, which is enough to ensure the use of time-of-flight technology to achieve the distinction between tritium and He-3. The residual energy of tritium is greater than that of He-3. The flight time of tritium is less than that of He-3 through the same distance. The flight time spectra of tritium and He-3 are different, thereby achieving the distinction between tritium and He-3.

[0049] In order to effectively realize the identification of ions by time-of-flight technology and the flexibility of detector use, the flight distance of ions is about 50 cm. In order to improve the identification ability of time-of-flight, a microchannel plate with a fast rise time is used to measure ions. The positive hydrogen ions and helium ions after passing through the film are finally measured by the microchannel plate 50 cm away from the film and give the stop time signal of the time-of-flight detection system. In order to eliminate the interference of stray particles and improve the time resolution ability, a circular slit with a diameter of about 5 mm is set in front of the microchannel detector.

[0050] The time-of-flight detection system uses the start time triggered by the laser and the stop time signal measured by the microchannel plate detector. These two signals form the time-of-flight detection system. The measured start time signal and stop time signal are sent to a hardware device (time-to-amplitude converter) that can realize time-to-amplitude conversion. This device can convert the flight time of the ion into a voltage amplitude signal (that is, the longer the flight time, the higher the voltage signal generated, and they are proportional). Then, the amplitude data conversion hardware (ADC) and the supporting analysis software can be used to measure the flight time spectrum. Since the mass or energy of H-1, H-2, H-3, He-3, etc. are different, their flight time is also different, so they are in different positions on the flight time spectrum. The different flight times of hydrogen and helium isotopes in the flight time spectrum can realize the online analysis of the hydrogen and helium isotope content in the sample.

[0051] The method for online analysis of hydrogen and helium isotopes based on time of flight comprises the following steps:

[0052] Step 1, placing a sample containing hydrogen and helium isotopes on a stand;

[0053] Step 2, using a pulsed laser to act on a sample containing hydrogen and helium isotopes and ionize the sample into hydrogen positive ions and helium positive ions, and using the pulsed laser emission time as a start time signal of a time-of-flight detection system;

[0054] Step 3, using the electric field between the gantry and the extraction electrode to extract the positive hydrogen ions and the positive helium ions and accelerate them to appropriate energy;

[0055] Step 4, using the film as an energy absorption membrane to allow hydrogen ions and helium ions to pass through the film;

[0056] Step 5: In order to eliminate the interference of stray particles and improve the time resolution, the positive hydrogen ions and the positive helium ions are allowed to pass through the slit;

[0057] Step 6, a detector at an appropriate distance from the film is used to measure and provide a stop time signal of the time-of-flight detection system;

[0058] Step 7, using the time-of-flight detection system to obtain a time-of-flight spectrum through a time-amplitude conversion system, and realizing online analysis of the hydrogen and helium isotope contents by using the different flight times of hydrogen and helium isotopes in the time-of-flight spectrum.

[0059] Take the time-of-flight device based on online analysis of hydrogen and helium isotopes as an example:

[0060] Embodiment 1

[0061] The time-of-flight device for online analysis of hydrogen and helium isotopes in this embodiment adopts the following method: Figure 1 As shown in the structure, the entire system consists of a laser, a stand, an extraction electrode, a film, a slit, a detector and other parts. The entire part is in a vacuum chamber, and an external vacuum pump is connected to keep the system in a vacuum environment.

[0062] The solid sample containing hydrogen and helium isotopes was placed on a high voltage stand with a voltage of +48KV, and the incident window was made of MgF 2 The material is glass, and a pulse laser is used to act on the sample and ionize the sample into positive hydrogen ions and positive helium ions. At the same time, the pulse laser emission time is used as the starting time signal of the time-of-flight detection system.

[0063] A pre-extraction electrode in the shape of a grid is provided between the solid sample and the extraction electrode and close to the solid sample. The voltage of the pre-extraction electrode is set to 47 KV.

[0064] The voltage of the extraction electrode is set to 0V, and the potential difference between the high-voltage stand containing the hydrogen and helium isotope sample and the extraction electrode is used to extract the hydrogen and helium ions produced by ionization and accelerate them to an energy of 48KeV.

[0065] A silicon nitride film with very good thickness uniformity is used as the energy absorption film. Considering the requirements for ion energy loss, the thickness of the silicon nitride film used is 30nm.

[0066] The accelerated hydrogen ions and helium ions pass through a 30nm thick silicon nitride film.

[0067] The hydrogen ions and helium ions that pass through the film are finally measured by a microchannel plate 50 cm away from the film and give a stop time signal for the time-of-flight detection system. In order to eliminate interference from stray particles and improve time resolution, a circular slit with a diameter of 4 mm is set in front of the microchannel detector.

[0068] A time-of-flight detection system is formed by using the start time signal of the pulsed laser emission and the stop time signal of the microchannel plate detector. The time-of-flight spectrum can be obtained through the time-to-amplitude conversion system (time-to-amplitude converter) of the time-of-flight spectrum. The different flight times of hydrogen and helium isotopes in the time-of-flight spectrum can be used to realize online analysis of the hydrogen and helium isotope content in solid samples.

[0069] Embodiment 2

[0070] The time-of-flight device for online analysis of hydrogen and helium isotopes in this embodiment adopts the following method: Figure 1 As shown in the structure, the entire system consists of a laser, a stand, an extraction electrode, a film, a slit, a detector and other parts. The entire part is in a vacuum chamber, and an external vacuum pump is connected to keep the system in a vacuum environment.

[0071] A gas sample containing hydrogen and helium isotopes flows into a high-voltage test bench with a voltage of +50KV through a quartz microporous tube. The incident window is made of borosilicate glass. A pulsed laser is used to act on the sample and ionize the sample into hydrogen positive ions and helium positive ions. At the same time, the pulsed laser emission time is used as the starting time signal of the time-of-flight detection system.

[0072] A pre-extraction electrode in the shape of a grid is provided between the gas sample and the extraction electrode and close to the gas sample. The voltage of the pre-extraction electrode is set to 49KV.

[0073] The voltage of the extraction electrode is set to 0V, and the potential difference between the high-voltage stand containing the hydrogen and helium isotope sample and the extraction electrode is used to extract the hydrogen and helium ions produced by ionization and accelerate them to an energy of 50KeV.

[0074] A silicon nitride film with very good thickness uniformity is used as the energy absorption film. Considering the requirements for ion energy loss, the thickness of the silicon nitride film used is 30nm.

[0075] The accelerated hydrogen ions and helium ions pass through a 30nm thick silicon nitride film.

[0076] The hydrogen ions and helium ions that pass through the film are finally measured by a microchannel plate 50 cm away from the film and give a stop time signal for the time-of-flight detection system. In order to eliminate interference from stray particles and improve time resolution, a circular slit with a diameter of 6 mm is set in front of the microchannel detector.

[0077] A time-of-flight detection system is formed by using the start time signal of the pulsed laser emission and the stop time signal of the microchannel plate detector. The time-of-flight spectrum can be obtained through the time-to-amplitude conversion system (time-to-amplitude converter) of the time-of-flight spectrum. The different flight times of hydrogen and helium isotopes in the time-of-flight spectrum can be used to realize online analysis of the hydrogen and helium isotope content in the gas sample.

[0078] Take the time-of-flight method for online analysis of hydrogen and helium isotopes as an example:

[0079] Embodiment 3

[0080] Step 1, placing a solid sample containing hydrogen and helium isotopes on a high voltage stand with a voltage of about +48KV;

[0081] Step 2: The entrance window is made of MgF 2 Glass of the material, using pulsed laser to act on the sample containing hydrogen and helium isotopes and ionize the sample into positive hydrogen ions and positive helium ions, and using the pulsed laser emission time as the starting time signal of the time-of-flight detection system;

[0082] Step 3, the voltage of the pre-extraction electrode is set to 47KV, the voltage of the extraction electrode is set to 0V, and the positive hydrogen ions and positive helium ions are extracted and accelerated to an energy of 48KeV by using the electric field between the high-voltage stand and the extraction electrode;

[0083] Step 4, using a silicon nitride film as an energy absorption film, the thickness of the silicon nitride film is 30nm, and allowing hydrogen ions and helium ions to pass through the silicon nitride film;

[0084] Step 5: In order to eliminate the interference of stray particles and improve the time resolution, the positive hydrogen ions and positive helium ions are allowed to pass through a circular slit with a diameter of 4 mm;

[0085] Step 6, the microchannel plate at a distance of 50 cm from the film is used to measure and provide a stop time signal of the time-of-flight detection system;

[0086] Step 7, using the start time signal of the pulse laser emission and the stop time signal of the microchannel plate detector to form a time-of-flight detection system, the time-of-flight spectrum can be obtained through the time-to-amplitude conversion system (time-to-amplitude converter) of the time-of-flight spectrum, and the online analysis of the hydrogen and helium isotope content in the solid sample can be achieved through the different flight times of hydrogen and helium isotopes in the time-of-flight spectrum.

[0087] Embodiment 4

[0088] Step 1, a gas sample containing hydrogen and helium isotopes is flowed into a high-voltage stand with a voltage of about +50KV through a quartz microporous tube;

[0089] Step 2, the incident window is made of borosilicate glass, and a pulsed laser is used to act on a sample containing hydrogen and helium isotopes to ionize the sample into hydrogen positive ions and helium positive ions, and the pulsed laser emission time is used as the starting time signal of the time-of-flight detection system;

[0090] Step 3, the voltage of the pre-extraction electrode is set to 49KV, the voltage of the extraction electrode is set to 0V, and the positive hydrogen ions and positive helium ions are extracted and accelerated to an energy of 50KeV by using the electric field between the high-voltage stand and the extraction electrode;

[0091] Step 4, using a silicon nitride film as an energy absorption film, the thickness of the silicon nitride film is 30nm, and allowing hydrogen ions and helium ions to pass through the silicon nitride film;

[0092] Step 5: In order to eliminate the interference of stray particles and improve the time resolution, the positive hydrogen ions and positive helium ions are allowed to pass through a circular slit with a diameter of 6 mm;

[0093] Step 6, the microchannel plate at a distance of 50 cm from the film is used to measure and provide a stop time signal of the time-of-flight detection system;

[0094] Step 7, using the start time signal of the pulse laser emission and the stop time signal of the microchannel plate detector to form a time-of-flight detection system, the time-of-flight spectrum can be obtained through the time-to-amplitude conversion system (time-to-amplitude converter) of the time-of-flight spectrum, and the online analysis of the hydrogen and helium isotope content in the gas sample can be achieved through the different flight times of hydrogen and helium isotopes in the time-of-flight spectrum.

[0095] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A hydrogen and helium isotope online analysis device based on time of flight, characterized in that: The invention comprises a cavity, a laser, a stand, an extraction electrode, a film, a slit and a detector arranged in the cavity. The cavity is connected to a vacuum pump outside to make the cavity in a vacuum. The laser uses pulsed laser to ionize hydrogen and helium isotopes on the stand into hydrogen positive ions and helium positive ions through an incident window arranged on the cavity, and uses the pulsed laser emission time as a start time signal of a time-of-flight detection system. The hydrogen positive ions and helium positive ions are extracted and accelerated to appropriate energy through the electric field between the stand and the extraction electrode. The hydrogen positive ions and helium positive ions pass through the film and the slit, and are measured by the detector and a stop time signal of the time-of-flight detection system is given. The time-of-flight detection system is used to obtain a time-of-flight spectrum through a time-amplitude conversion system to realize online analysis of the hydrogen and helium isotope contents.

2. The on-line hydrogen and helium isotope analysis device based on time of flight as claimed in claim 1, characterized in that: The stand, lead-out electrode, film, slit and detector are sequentially arranged in the cavity along the axis.

3. The on-line hydrogen and helium isotope analysis device based on time of flight as claimed in claim 1, characterized in that: The incident window is made of MgF2 or borosilicate glass, which can enhance the transmittance of the laser.

4. The on-line hydrogen and helium isotope analysis device based on time of flight as claimed in claim 1, characterized in that: The bench voltage is 48-50 kV, and the extraction electrode voltage is 0V.

5. The on-line hydrogen and helium isotope analysis device based on time of flight as claimed in claim 4, characterized in that: A grid-shaped pre-extraction electrode is arranged between the stage and the extraction electrode, and the pre-extraction electrode voltage is 1 kV lower than the stage voltage. The extraction and focusing of positive ions are achieved by voltage matching between the pre-extraction electrode and the extraction electrode.

6. The on-line hydrogen and helium isotope analysis device based on time of flight as claimed in claim 5, characterized in that: If the hydrogen and helium isotopes are in the form of gas, they flow into the rack through a quartz microporous tube.

7. The on-line hydrogen and helium isotope analysis device based on time of flight as claimed in claim 4, characterized in that: The electric field between the stage and the extraction electrode accelerates the hydrogen positive ions and the helium positive ions to an energy of 48 to 50 KeV.

8. The on-line hydrogen and helium isotope analysis device based on time of flight as claimed in claim 1, characterized in that: The film is a silicon nitride film.

9. The on-line hydrogen and helium isotope analysis device based on time of flight as claimed in claim 8, characterized in that: The thickness of the silicon nitride film is 30 nm.

10. The on-line hydrogen and helium isotope analysis device based on time of flight as claimed in claim 1, characterized in that: The slit is circular, with a diameter of 4 to 6 mm.

11. The on-line hydrogen and helium isotope analysis device based on time of flight as claimed in claim 1, characterized in that: The distance between the detector and the film is 50 cm.

12. The on-line hydrogen and helium isotope analysis device based on time of flight as claimed in claim 1, characterized in that: The detector is a microchannel plate.

13. A method for online analysis of hydrogen and helium isotopes based on time of flight using the device according to any one of claims 1 to 12, characterized in that: The following steps are involved: Step 1, placing a sample containing hydrogen and helium isotopes on a stand; Step 2, using a pulsed laser to act on a sample containing hydrogen and helium isotopes and ionize the sample into positive hydrogen ions and positive helium ions, and using the pulsed laser emission time as a start time signal of a time-of-flight detection system; Step 3, using the electric field between the gantry and the extraction electrode to extract the positive hydrogen ions and the positive helium ions and accelerate them to appropriate energy; Step 4, using the film as an energy absorption membrane to allow hydrogen ions and helium ions to pass through the film; Step 5: In order to eliminate the interference of stray particles and improve the time resolution, the positive hydrogen ions and the positive helium ions are allowed to pass through the slit; Step 6, a detector at an appropriate distance from the film is used to measure and provide a stop time signal of the time-of-flight detection system; Step 7, using the time-of-flight detection system to obtain a time-of-flight spectrum through a time-amplitude conversion system, and realizing online analysis of the hydrogen and helium isotope contents by using the different flight times of hydrogen and helium isotopes in the time-of-flight spectrum.

14. The method for online analysis of hydrogen and helium isotopes based on time of flight as claimed in claim 13, characterized in that: In step 1, a solid sample containing hydrogen and helium isotopes is placed directly on the stage.

15. The method for online analysis of hydrogen and helium isotopes based on time of flight as claimed in claim 13, characterized in that: In step 1, a gas sample containing hydrogen and helium isotopes flows into the stage through a quartz microbore tube.

16. The method for online analysis of hydrogen and helium isotopes based on time of flight as claimed in claim 13, characterized in that: In step 1, the bench voltage is 48-50 kV.

17. The method for online analysis of hydrogen and helium isotopes based on time of flight as claimed in claim 16, characterized in that: In step 3, the extraction electrode voltage is 0V, and the hydrogen cations and helium cations are accelerated to an energy of 48 to 50 KeV.

18. The method for online analysis of hydrogen and helium isotopes based on time of flight as claimed in claim 13, characterized in that: In step 4, the film is a silicon nitride film with a thickness of 30 nm.

19. The method for online analysis of hydrogen and helium isotopes based on time of flight as claimed in claim 13, characterized in that: In step 6, the distance between the detector and the film is 50 cm.

20. The method for online analysis of hydrogen and helium isotopes based on time of flight as claimed in claim 13, characterized in that: In step 6, the detector is a microchannel plate.

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