Patent ID: 12222283

The reference numerals in the drawings are as follows:1: laser device;2: fiber coupler;3: dichroscope;4: single fiber;5: single-fiber LIBS probe;6: vacuum arc-extinguishing chamber;7: achromatic instrument;8: collection fiber;9: ICCD camera;10: spectrometer; and11: delay pulse generator.

The present disclosure will be further explained below in combination with the accompanying drawings and the embodiments.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Specific embodiments of the present disclosure will be described in more detail below with reference toFIG.1toFIG.2. Although specific embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

It should be noted that certain words are used in the description and claims to refer to specific components. Those skilled in the art should understand that they may use different terms to refer to the same component. This description and claims do not use differences in terms as a way to distinguish components, but use differences in functions of components as a criterion for distinguishing. If “including” or “include” mentioned in the entire description and claims is an open term, it should be interpreted as “including but not limited to”. The following description of the description is a preferred embodiment for implementing the present disclosure. However, the description is for the purpose of the general principles of the description and is not intended to limit the scope of the present disclosure. The protection scope of the present disclosure shall be subject to those defined by the appended claims.

In order to facilitate the understanding of the embodiments of the present disclosure, specific embodiments will be used as an example for further explanation in conjunction with the accompanying drawings, and the drawings do not constitute a limitation to the embodiments of the present disclosure.

As shown inFIG.1, an online vacuum degree detection system based on single-fiber laser-induced breakdown spectroscopy (LIBS) includes:a laser device1, which generates laser that excites the laser through fiber induced breakdown spectroscopy;a fiber coupler2, which couples and injects the laser;a single fiber4, which is connected to the fiber coupler2to transmit the laser;an LIBS probe5, one end of which is connected to the single fiber4, and the other end of which extends into a vacuum arc-extinguishing chamber6, wherein the laser is induced by the LIBS probe5to generate plasma, and the plasma is subjected to self-emission imaging and enters the fiber coupler2via the LIBS probe5;a dichroscope3, which is arranged on the fiber coupler2to separate the laser from the plasma;an achromatic instrument7, which is connected to the fiber coupler2;a collection fiber8, which is connected to the achromatic instrument7to collect the plasma;a spectrometer10, which is connected to the collection fiber8to generate a spectral signal;an ICCD camera9, which is connected to the spectrometer10to collect a plasma image;a digital delay pulse generator11, which is connected to the ICCD camera9to control the ICCD camera9by means of setting a delay between pulses; anda processor, which is connected to the ICCD camera9and the spectrometer10, wherein a plasma temperature and a plasma density are generated based on the plasma image and the spectral signal, so as to obtain a vacuum degree.

In a preferable embodiment of the online vacuum degree detection system based on single-fiber laser-induced breakdown spectroscopy, the energy of the laser generated by the laser device1is 24 mJ, and a wavelength is set to 1,064 nm.

In a preferable embodiment of the online vacuum degree detection system based on single-fiber laser-induced breakdown spectroscopy, a central glass core of the single fiber4has a core diameter of 400 μm-600 μm; a material of a core layer of the single fiber4adopts GeO2or SiO2.

In a preferable embodiment of the online vacuum degree detection system based on single-fiber laser-induced breakdown spectroscopy, the LIBS probe5is a single-lens-based LIES laser probe; during focusing, laser spots are focused and emitted through a lens to a shield target material of an arc-extinguishing chamber in a vacuum switch to generate plasma.

In one embodiment, the system includes a laser device1, a fiber coupler2, a dichroscope3, a transmission fiber, a single-fiber LIBS probe5, a vacuum arc-extinguishing chamber6, an achromatic instrument7, a collection fiber8, a digital delay pulse generator11, a plasma imaging system, a spectrometer10, and an ICCD camera9.

In one embodiment, the laser device1is used for generating high-energy laser with an energy of 24 mJ; the fiber coupler2reflects a main laser beam through the dichroscope3and injects the reflected main laser beam into the transmission fiber; the single-fiber LIBS probe5includes a small laser probe applied to a single-lens-based single-fiber laser-induced breakdown spectroscopy system and is used for inducing generation of plasma; the plasma imaging system shall include a lens for achieving a focusing effect in the single-fiber4LIBS probe5and the dichroscope3for separating plasma emission from a laser path; the emitted plasma is returned according to an original path, is separated from the laser path through the dichroscope3, and is transmitted by the achromatic instrument7to the collection fiber8. The digital delay pulse generator11controls, for example, the ICCD camera9by setting a delay between pulses. The spectral measurement system is applied to detecting a spectral signal generated by the plasma, includes the ICCD camera9and the spectrometer10, records the spectral signal and analyzes a spectral line composition, intensity, plasma temperature and plasma density to obtain a vacuum measurement result.

Preferably, due to a high laser flux of a focal plane, a fiber input end face is required to be placed at a proper distance behind a focus point, so as to ensure that the laser irradiance is less than a fiber damage threshold. Preferably, the distance between a fiber output end face and the lens is required to be considered. This is one of the factors that affect the size of a focused laser spot.

The present disclosure solves the problem of online monitoring of remote vacuum switch equipment. The noise interference during laser incidence is reduced through fiber transmission, so that the light loss is reduced, and the detection accuracy and efficiency are improved. Meanwhile, application scenarios of this application include, but are not limited to, an application to a power equipment switch, which is of great significance for predictability of the service life of a switch and an engineering type.

As shown inFIG.2, a detection method using the online vacuum degree detection system based on single-fiber laser-induced breakdown spectroscopy includes the following steps:the laser is coupled and injected into the single fiber4by the fiber coupler2and transmitted to the LIBS probe5to excite the shield of the arc-extinguishing chamber in the vacuum switch to induce generation of plasma;the plasma is subjected to self-emission imaging and enters the fiber coupler2via the LIB S probe5, the dichroscope3separates the laser from the plasma, and the collection fiber8collects the plasma via the achromatic instrument7;the digital delay pulse generator11triggers the laser and the camera9, a time interval is adjusted to track the evolution of the plasma, and the camera9and the spectrometer10obtain a plasma image and a spectral signal; andthe processor generates a plasma temperature and a plasma density based on the plasma image and the spectral signal, so as to obtain a vacuum degree.

In the detection method, the spectral signal includes an ion spectral line composition and intensity.

In one implementation, the online vacuum degree detection method includes the following steps: the laser device1generates high-energy laser; the laser is injected into the single fiber4for transmission to excite and induce the shield target material of the arc-extinguishing chamber in the vacuum switch; the output laser is focused by using an imaging principle; a laser spot on the fiber end face is imaged and mapped to a target surface through an aspherical lens to generate plasma. In this way, self-emission of the plasma is also imaged to an output end face of the fiber laser device1and the plasma is then transmitted back through the transmission fiber; the plasma emission is separated from the laser path via the dichroscope3; the plasma is guided by the achromatic instrument7to be emitted into the collection fiber8which is connected to the spectral measurement system. The delay pulse generator11is used to trigger a laser source and the ICCD camera9. The ICCD camera9is used to acquire an image of the plasma, and finally, a spectral signal result is analyzed to obtain a vacuum measurement numerical value.

In one implementation, the method includes:Step 1, the laser device1is used to emit high-energy laser which is coupled and injected into the fiber for exciting the shield of the vacuum arc-extinguishing chamber6to generate plasma. The energy of the laser transmitted by the fiber is 24 mJ, and a wavelength is set to 1,064 nm, so as to ensure inducing generation of plasma to complete subsequent measurement of a vacuum degree.Step 2, a main laser beam generated in the step 1 is injected into the transmission fiber through the laser fiber coupler2via the dichroscope3, and the fiber used in an experiment is a single fiber4.Step 3, the laser transmitted by the fiber in the step 2 is focused inside the vacuum arc-extinguishing chamber6through the single-fiber4LIBS probe5to generate plasma converged into a point.Step 4, the digital delay pulse generator11is configured to trigger the laser and the ICCD camera9; a time interval is adjusted to track the evolution of the plasma or shock wave; the plasma generated in the step 3 is transmitted back through the ICCD camera9via the transmission fiber, is separated from the laser path through the dichroscope3, and is transmitted to the collection fiber8which is connected to the spectral measurement system by the achromatic instrument7; the ICCD is used for taking pictures; a filter is placed in front of the camera to filter plasma radiation and background noise to obtain a plasma image; and analysis is performed to obtain a vacuum degree.

In the online vacuum degree detection method based on single-fiber laser-induced breakdown spectroscopy, the single-fiber LIBS probe5is applied, and a single-fiber-based laser-induced plasma imaging system and a spectral diagnosis system are designed to achieve the online vacuum degree measurement method based on a single-fiber LIBS plasma imaging technology. The system includes a laser device1, a fiber coupler2, a dichroscope3, a transmission fiber, a single-fiber LIBS probe5, a vacuum arc-extinguishing chamber6, an achromatic instrument7, a collection fiber8, a delay pulse generator11, a plasma imaging system, and a spectral measurement system. According to the above step 1, the laser device1is used to generate high-energy laser, and the energy is set to 24 mJ; the fiber coupler2is used to reflect a main transmission beam into the transmission fiber through the dichroscope3; the single-fiber LIBS probe5includes a small laser probe based on a single-lens-based single-fiber4laser-induced breakdown spectroscopy system for inducing generation of plasma; the achromatic instrument7is used to guide the plasma into the collection fiber8; the digital delay pulse generator11controls the ICCD camera9by setting a delay between pulses; the plasma imaging system shall be provided with a lens for focusing and the dichroscope3for separating the laser from the plasma; the dichroscope3is used to reflect the laser and separate the plasma from the laser beam; the spectral measurement system shall include the ICCD camera9and the spectrometer10that complete the step 5, and are applied to detecting the spectral signal generated by the plasma, recording the spectral signal, analyzing the atom and ion spectral line compositions and intensities, and finally calculating a plasma temperature and a plasma density to obtain a vacuum measurement result.

Preferably, the laser device1can generate laser with an energy of 24 mJ and a wavelength of 1,064 nm; the energy of the laser with the specific wavelength can be transmitted through the fiber coupler2via the single fiber4, and the energy of the laser transmitted by the single fiber4can induce, through the LIB S probe5, the shield target material of the arc-extinguishing chamber in the vacuum switch to generate plasma. Preferably, the plasma is separated from the laser beam by the dichroscope3and transmitted to the collection fiber8by the achromatic instrument7for imaging via the ICCD camera9. Preferably, the spectrometer10in the spectral measurement system can process different spectral lines of the plasma, including atomic lines and ion lines, and determine a vacuum degree through spectral line intensity analysis.

Although the embodiments of the present disclosure have been described above in conjunction with the accompanying drawings, the present disclosure is not limited to the above specific embodiments and application fields. The above specific embodiments are only illustrative and instructive, but not restrictive. Under the enlightenment of this description and without departing from the scope of protection of the claims of the present disclosure, those of ordinary skill in the art can also make many forms, which all fall within the protection of the present disclosure.