Method and system for simulating space orbit electron radiation environment

Abstract

The invention provides a method and a system for simulating a space orbit electron radiation environment. The system comprises a femtosecond laser system, an optical system, a composite target, a magnet, a beam detector and an electron spectrometer which are connected in sequence. The method for simulating the space orbit electron radiation environment by adopting the system comprises the following steps: acquiring target orbit information, and obtaining electron energy spectrum information corresponding to the target orbit; under the condition of fixing the laser and the parameters of the target II, changing the density and length of the target I, collecting the energy and number information of electron beams generated after the target II is collected, and obtaining the energy spectrum information of the electron beams and the corresponding electron temperature and electron cut-off energy of the electron beams; and when the electron temperature and the electron cut-off energy obtained by adjusting the density and the length of the target I are matched with those of the target orbit, obtaining the electron radiation environment of the target orbit. According to the invention, ground simulation of the space orbit electron radiation environment can be realized, and the blank of ground simulation of different orbit radiation environments in the field of space radiation environment simulation is filled.

Description

Technical Field

[0001] The present invention relates to the fields of novel particle acceleration technology and space radiation environment technology, and in particular, to a method and system for simulating space orbit electron radiation environment. Background Art

[0002] Under the influence of the geomagnetic field, there are a large number of electrons with energies below 10 MeV in the Earth's radiation belt. The energy spectrum structure of these electrons after accumulation presents a nearly exponential distribution, which has the characteristics of a wide energy spectrum. At present, the space radiation environment simulation device based on traditional accelerators cannot produce such electron beams. Therefore, there are problems such as equivalence of space radiation simulation, and it is difficult to accurately characterize the radiation effects of space particles. The rapid development of laser accelerators has provided an effective method for the generation of wide energy spectrum electron beams. For example, by using a focused power density of 10 18 -10 20 W / cm 2 It is easier to produce exponentially wide-energy-spectrum electron beams by bombarding solid targets with ultra-intense lasers.

[0003] At present, most of the research on simulating space electron radiation environment based on laser particle accelerators is achieved by directly bombarding high-density solid targets with lasers. This method has high requirements on laser focusing, and the energy spectrum structure of the generated electron beam is difficult to control, the divergence is large, and higher laser energy is required.

[0004] Therefore, there is an urgent need for a new technology of a method and system for simulating the space orbit electron radiation environment. Summary of the invention

[0005] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a method and system for simulating the space orbital electron radiation environment. Under the condition of fixing the laser parameters, the parameters of the target can be adjusted to obtain an electron beam that is adapted to the electron energy spectrum of different orbits in space, filling the gap in the field of space radiation environment simulation on the ground in simulating different orbital radiation environments, and can provide a theoretical analysis model for subsequent experimental work, which has certain guiding significance.

[0006] To achieve the above object, the present invention provides a system for simulating the electron radiation environment of a space orbit, the system comprising a femtosecond laser system, a vacuum chamber, an optical system, a composite target, a focusing magnetic field, a beam detector and an electron spectrometer;

[0007] The composite target, focusing magnetic field, beam detector and electron spectrometer are all arranged in a vacuum chamber;

[0008] The femtosecond laser system generates a beam of femtosecond laser, which is modulated by an optical system for transmission and focusing of the femtosecond laser. The modulated femtosecond laser is injected into a vacuum target chamber to ionize atoms of a composite target into plasma, and an accelerated electron beam is formed under the combined action of laser ponderomotive force or surface ponderomotive force acceleration and J×B heating mechanism. The electron beam is injected into a beam current monitor after passing through a focusing magnetic field to obtain information on the charge amount and divergence angle of the electrons, and then an energy spectrum of the electron beam is obtained through an electron spectrometer, thereby realizing ground simulation of electron radiation environments of different orbits in space;

[0009] The composite target is T-shaped, including a target I and a target II which are arranged perpendicular to each other, and the incident direction of the femtosecond laser is parallel to the target I.

[0010] Furthermore, the target I is an aerogel target or a carbon nanotube target whose density and length can be adjusted; and the target II is a solid aluminum target or a hydrocarbon target.

[0011] Furthermore, 3D printing technology was used to obtain aerogel targets I with different densities and lengths, and they were combined with solid aluminum target II through an adhesive.

[0012] Furthermore, the electron number density of the target I is 5×10 19 cm -3 ~1.1×10 22 cm -3 , length is 1μm~8μm, width is 0.1μm~1μm;

[0013] The electron number density of target II is 2×10 22 cm -3 ~3×10 23 cm -3 , length is 20μm~200μm, width is 10μm~80μm.

[0014] Furthermore, the beam detector and the electronic spectrometer are both connected to a computer.

[0015] Furthermore, the focusing magnetic field is a magnet.

[0016] Furthermore, the composite target is arranged in a vacuum target chamber to fix the combined target I and target II.

[0017] Furthermore, the normalized intensity of the femtosecond laser is 2.8-4.7, corresponding to a peak power of 1×10 19 W / cm 2 ~3×10 19 W / cm 2 , the pulse length is 20fs~80fs, and the focal spot radius is 3μm~8μm.

[0018] The present invention also provides a method for simulating a space orbit electron radiation environment, using a system for simulating a space orbit electron radiation environment as described above to conduct an experiment, comprising the following steps:

[0019] Acquire target orbit information to obtain electron energy spectrum information corresponding to the target orbit; the electron energy spectrum information corresponding to the target orbit includes electron temperature and electron cutoff energy;

[0020] Under the condition of fixing the laser parameters and target II parameters, the density and length information of target I are changed, the energy and number information of the electron beam generated after target II are collected, and the energy spectrum information of the electron beam and its corresponding electron temperature and electron cutoff energy are obtained;

[0021] When the electron temperature and electron cutoff energy obtained by adjusting the density and length information of target I match the electron energy spectrum information corresponding to the target orbit, the electron radiation environment of the target orbit is obtained.

[0022] Further, the target orbital information is obtained to obtain the electronic energy spectrum information corresponding to the target orbital, specifically:

[0023] Obtain the perigee and apogee heights, inclination, and running time of the target orbit, and use the AE8 or AE9 model to calculate the electron energy spectrum of the target orbit.

[0024] Directly obtaining the electron cutoff energy of the target orbit according to the electron energy spectrum of the target orbit;

[0025] According to the electron energy spectrum of the target orbit, the electron temperatures of the low energy segment and the high energy segment are calculated respectively.

[0026] The present invention has the following beneficial effects:

[0027] 1. The present invention determines the electron temperature in a specific energy region of the space orbit electron energy spectrum by fixing the initial laser wavelength, normalized intensity, and laser pulse width, and selects appropriate target parameters to obtain an electron beam that matches it. The electron energy spectrum of the specified orbit is obtained using the AE8 or AE9 model, and the electron temperature is calculated by fitting the electron energy spectrum in the low-energy and high-energy segments respectively. The combined target used is composed of target I and target II, wherein the density and length of target I are adjustable to adjust the temperature of the generated electron beam; the material of target I is aerogel or carbon nanotube, and its density can be adjusted in 1n c The electron energy spectra generated by targets with different parameters are statistically analyzed to obtain the electron temperatures in different energy ranges, and the generated electron energy spectra are all exponential wide spectrum structures. The composite structure target used in the present invention can fill the gap in the simulation of space electron radiation environment in multi-orbit different radiation environments, which is of great significance for the study of space radiation effects on the ground, and the target type is simple and easy to make, which is conducive to controlling the cost of target material production.

[0028] 2. For the space radiation environment, the orbital radiation environment at different altitudes is very different. The present invention uses a laser-driven electron acceleration method to simulate the electron radiation of different orbits, which can achieve the simulation of various complex environments at a relatively low cost. By utilizing the changes in the electron acceleration mechanism in plasmas of different densities and the control of the target length, the electron energy spectrum can be regulated to match the electron radiation environment of different orbits. The present invention combines theory and two-dimensional particle simulation experiments to propose a target design scheme for the space orbital electron radiation environment. The scheme analyzes the electron temperature of different orbits and counts the changes in electron temperature to adjust the density and length parameters of target I so that the electron beam generated by the interaction between the laser and the target can match the electron radiation environment of the specified orbit.

[0029] 3. The present invention can obtain femtosecond laser pulses by selecting different lasers and optical system settings, and use 3D printing technology to obtain aerogel targets I with different densities and lengths, and combine them with solid aluminum targets or hydrocarbon targets II through adhesives. After the laser is incident, the electron beam accelerated by the incident laser passes through the magnetic focusing system and then enters the electron beam diagnostic system, which can analyze the energy spectrum and angular divergence of the electron beam, thereby realizing the ground simulation of the electron radiation environment of different orbits in space.

[0030] 4. The present invention provides a method and system for simulating the space orbit electron radiation environment, which can not only provide analytical guidance for ground simulations of different orbit electron radiation environments and help experiments select targets with appropriate parameters, but also the solution has many application scenarios and provides a solution for conducting multi-field radiation effect research on ground simulations of space radiation environments.

[0031] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0033] Figure 1 It is a structural schematic diagram of a system for simulating space orbit electron radiation environment provided by the present invention;

[0034] Figure 2 The present invention provides a schematic diagram of a composite target in a system for simulating a space orbit electron radiation environment and a parameter diagram of a composite target; wherein: Figure 2 (a) is the schematic diagram of the composite target. Figure 2 (b) is the parameter diagram of the composite target;

[0035] Figure 3 It is a flow chart of a method for simulating space orbit electron radiation environment provided by the present invention;

[0036] Among them, 1. Femtosecond laser system, 2. Optical system, 3. Composite target, 4. Magnet, 5. Beam detector, 6. Electronic spectrometer, 7. Computer, 8. Vacuum chamber, 9. Vacuum target chamber. DETAILED DESCRIPTION

[0037] The embodiments of the present invention are described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0038] like Figure 1 and Figure 2 As shown, the present invention provides a system for simulating the space orbit electron radiation environment, the system comprising a femtosecond laser system 1, a vacuum chamber 8, an optical system 2, a composite target 3, a focusing magnetic field, a beam detector 5 and an electronic spectrometer 6; the composite target 3, the focusing magnetic field, the beam detector 5 and the electronic spectrometer 6 are all arranged in the vacuum chamber 8;

[0039] The femtosecond laser system 1 is used to generate a femtosecond laser. After the femtosecond laser is injected into the optical system 2, a modulated femtosecond laser is obtained. The modulated femtosecond laser is injected into the vacuum target chamber 9 to ionize the atoms of the composite target 3 into plasma, and an accelerated electron beam is formed under the combined action of laser ponderomotive force or surface ponderomotive force acceleration and J×B heating mechanism. After the electron beam passes through the focusing magnetic field, it is first injected into the beam detector 5 to obtain the charge amount and divergence angle information of the electron beam, and then injected into the electron spectrometer 6 to obtain the energy spectrum of the electron beam, thereby realizing the ground simulation of the electron radiation environment of different orbits in space.

[0040] The composite target 3 is T-shaped, including target I and target II arranged perpendicularly to each other; the incident direction of the modulated femtosecond laser is parallel to target I, that is, it first enters target I in the composite target 3 in parallel and then enters target II perpendicularly.

[0041] In a specific embodiment, the femtosecond laser system 1 includes a laser, a filter and a compression amplifier connected in sequence, which are used to provide femtosecond lasers with intensity and pulse width. The optical system 2 includes an optical transmission device and a laser focusing device, which are used to modulate the focal spot and angle of the laser and control laser transmission and focusing. The composite target 3 is arranged in a vacuum target chamber 9, which is used to fix the combined target I and target II. The focusing magnetic field is a magnet 4, which can focus the accelerated electron beam. The beam detector 5 obtains the charge amount and divergence angle information of the electron beam, and the electronic spectrometer 6 obtains the energy spectrum of the electron beam. The beam detector 5 and the electronic spectrometer 6 are both electrically connected to a computer 7 for exporting simulation experimental data.

[0042] In a specific embodiment, the target I is an aerogel target or a carbon nanotube target with adjustable density and length; the plasma target II is a high-density solid aluminum target or a hydrocarbon target. Aerogel targets I with different densities and lengths are obtained by 3D printing technology, and are combined with solid aluminum target II by adhesive. The electron beam energy information described in the present invention can be obtained by a beam detector and an electron spectrometer, and can be quickly derived by a computer in a numerical simulation experiment. The material of target I is aerogel, and currently 3D printing technology can generate square targets of specific density and length.

[0043] The electron number density of target I is 5×10 19 cm -3 ≤n e ≤1.1×10 22 cm -3 , length 1μm≤l≤8μm, width 0.1μm≤d≤1μm. The electron number density of target II is 2×10 22 cm -3 ≤n e ≤3×10 23 cm -3 , length 20μm≤l≤200μm, width 10μm≤D≤80μm.

[0044] The normalized intensity of femtosecond laser is 2.8≤a0≤4.7, corresponding to a peak power of 1×10 19 W / cm 2 ≤I0≤3×10 19 W / cm 2 , the pulse length is 20fs≤τ≤80fs, and the focal spot radius is 3μm≤σ≤8μm. Preferably, the initial laser is set to a normalized intensity a0=3.2, the incident laser propagates along the x-axis, is polarized along the y-axis, and is a Gaussian pulse in both the transverse and longitudinal directions. The laser field intensity expression is:

[0045]

[0046] Where ξ=x-ct is the co-moving coordinate, r is the lateral distance from the optical axis, the laser pulse width τ0=40fs, and the focal spot radius σ0=5μm.

[0047] The laser electron acceleration experiment in the present invention is specifically as follows: a femtosecond laser system generates a beam of linearly polarized femtosecond laser, the femtosecond laser modulates the focal spot and angle of the femtosecond laser through an optical system, the modulated femtosecond laser is injected into the target chamber to ionize the atoms in the combined target into plasma, and an accelerated electron beam is formed under the combined action of laser ponderomotive force or surface ponderomotive force acceleration and J×B heating mechanism, different target parameters are used to produce different acceleration effects, thereby obtaining electron beams with different electron temperatures.

[0048] For the space radiation environment, the orbital radiation environment at different altitudes is very different. The present invention uses the laser particle acceleration method to simulate the electron radiation of different orbits, which can achieve the simulation of various complex environments at a relatively low cost. By utilizing the changes in the electron acceleration mechanism in plasmas of different densities and the control of the target length, the electron energy spectrum can be regulated to match the electron radiation environment of different orbits. Under the condition of fixing the laser parameters and the target II parameters, the present invention can obtain an electron beam that adapts to the electron energy spectrum of different orbits in space by adjusting the density and length information of target I, and then simulate the electron radiation environment of different orbits in space, filling the gap in the field of space radiation environment simulation in simulating different orbital radiation environments on the ground, and can provide a theoretical analysis model for subsequent experimental work, which has certain guiding significance.

[0049] like Figure 3 As shown, the present invention also provides a method for simulating a space orbit electron radiation environment, which uses the above-mentioned space orbit electron radiation environment simulation system to conduct an experiment, specifically comprising the following steps:

[0050] Step 1, determine the height, inclination, and running time of the perigee and apogee of the target orbit, use the AE8 or AE9 model to calculate the electron energy spectrum of the target orbit, and directly obtain the electron cutoff energy of the target orbit based on the electron energy spectrum of the target orbit; calculate the fitted electron temperatures of the low energy end (less than 1 MeV) and the high energy end (greater than 1 MeV) based on the electron energy spectrum of the target orbit.

[0051] Step 2: After determining the target orbital electron temperature, within the laser and target parameter range, that is, the laser normalized intensity is 2.8≤a0≤4.7, corresponding to the peak power of 1×10 19 W / cm 2 ≤I0≤3×10 19 W / cm 2 , pulse length 20fs≤τ≤80fs, focal spot radius 3μm≤σ≤8μm, target I electron number density 5×10 19 cm -3 ≤n e ≤1.1×10 22 cm -3 , length 1μm≤l≤8μm, width 0.1μm≤d≤1μm, target II electron number density 2×10 22 cm -3 ≤n e ≤3×10 23 cm -3 , length 20μm≤l≤200μm, width 10μm≤D≤80μm, select appropriate initial parameters.

[0052] Step 3: According to the initial parameters: laser normalized intensity a0 = 3.2, corresponding to peak power I0 = 1.4 × 10 19 W / cm 2 , pulse length τ = 40 fs, focal spot radius σ = 5 μm, target I electron number density n e =1.1×10 20 cm -3 , length l = 3 μm, width d = 1 μm, target II electron number density n e =6.6×10 22 cm -3 , length L = 30 μm, width D = 10 μm, the electron cutoff energy is 5.6 MeV, and the high-energy electron temperature is 0.64 MeV. Keeping the laser parameters and target II parameters unchanged, the density and length of target I are adjusted. When the density increases, the electron cutoff energy increases, and the electron temperature increases. Among them, the density is 3.3×10 20 cm -3 When the length is below 1 μm, the electron cutoff energy increases slightly, about 1 MeV in the range of 1 μm-8 μm, the electron temperature increases by about 0.2 MeV, and the density exceeds 3.3×10 20 cm -3 When the length is increased, it brings obvious gain effect on the electron cutoff energy and electron temperature. The maximum increase is about 9MeV in the range of 1μm-8μm, and the electron temperature increases by about 1.5MeV.

[0053] Step 4: Input each parameter into the particle simulation program LAPINE for two-dimensional simulation calculation, count the momentum and quantity information of the electrons collected after target II, calculate the electron energy spectrum and the electron temperatures at the low-energy and high-energy ends, and directly obtain the electron cutoff energy.

[0054] Step 5: When the electron temperature and electron cutoff energy obtained by adjusting the density and length information of target I match the electron energy spectrum information corresponding to the target orbit, the electron radiation environment of the target orbit is obtained.

[0055] The method of the present invention determines the target orbit energy spectrum structure information, calculates the electron energy spectrum to obtain the electron temperature at the low energy end and the high energy end, determines the laser intensity, focal spot radius, pulse width, and the density and size of target I and target II, and obtains an electron beam that matches the target orbit electron radiation energy spectrum. The present invention obtains an electron beam that matches the target orbit electron energy spectrum by selecting specific laser and target parameters through a two-dimensional particle simulation experiment, obtains the degree of matching between the electron energy spectrum structure obtained by simple calculation and analysis, and combines theory to find that for target I with an electron number density less than n e =1×10 20 cm -3In the case of , the electron acceleration mechanism is dominated by the laser ponderomotive force. As the electron number density increases, the electron acceleration mechanism gradually transitions from the laser ponderomotive force to the surface ponderomotive force. At this time, the length of target I is positively correlated with the cutoff energy of the accelerated electrons. According to the conversion of these two acceleration mechanisms, the electron beam energy spectrum structure and electron temperature obtained by targets I with different densities and lengths can be effectively controlled, thereby obtaining a result that matches the electron energy spectrum of the target orbit well.

[0056] The present invention provides a method and system for simulating the electron radiation environment of a space orbit. By calculating the electron energy spectrum of the target orbit, determining the electron temperature, selecting various laser parameters within a certain range and combining the density and size of target I and target II in the target, an electron beam with a specific energy distribution is generated to match the space electron radiation energy spectrum of the target orbit. The inventive method can help provide a target design scheme based on laser particle acceleration for ground simulation of space radiation environment, obtain an electron beam with a specified energy distribution, and provide conditions for the study of radiation effects in fields such as materials science and biology.

[0057] The present invention is further explained and illustrated below in conjunction with specific implementation modes.

[0058] The method of the present invention is based on the ground simulation study of different orbital electron radiation environments based on laser particle acceleration using the two-dimensional particle simulation software LAPINE. Taking the GPS orbit electron energy spectrum as an example, the operating altitude is set to 36,000 km, the orbital inclination is 55°, and the operating time is 15 years. The electron energy spectrum cutoff energy calculated in the model software is 6.5 MeV, and the high-energy end fitting electron temperature is 0.62 MeV.

[0059] Set the laser normalized intensity a0 = 3.2, pulse width τ0 = 40fs, and focal spot radius σ0 = 5μm. The incident laser propagates along the x-axis, is polarized along the y-axis, and is Gaussian in both the transverse and longitudinal directions. The laser field intensity expression is:

[0060]

[0061] Where ξ=x-ct is the co-moving coordinate, and r is the lateral distance from the optical axis.

[0062] According to the initial parameters, the electron beam cutoff energy is 5.6MeV and the electron temperature at the high energy end is 0.64MeV. The goal is to increase the electron cutoff energy. The electron number density of target I can be increased to increase the cutoff energy, while reducing the length of target I. Set the electron number density of target I n e =8.3×10 20 cm -3 , length l = 2.4 μm, width d = 1 μm, solid aluminum target II, electron number density n e =6.6×10 22 cm -3, length L = 30 μm, width D = 10 μm.

[0063] The parameters of the laser and the target were imported into the two-dimensional particle simulation software LAPINE for calculation. The simulation window was selected as 40 μm × 30 μm to reduce unnecessary calculations, and the grid was divided into 8000 × 2000. Each grid contained 20 macroparticles, and each macroparticle represented 5000 electrons or ions.

[0064] After the calculation is completed, the electron energy distribution information is collected, and the electron cutoff energy is 5.9MeV. The electron temperature at the high energy end is calculated to be 0.63MeV, which is consistent with the electron temperature at the high energy end of the target orbit.

[0065] This scheme is universal for the space electron radiation environment with orbital altitudes between 500 km and 40,000 km, that is, the electron cutoff energy is concentrated within 8MeV, and the electron temperature is in the range of 0.4-1MeV. The parameters of the laser and target selected within the scope of the claims can satisfy the simulation calculation within this range.

[0066] The present invention is very easy to apply in numerical simulation experiments. The target orbit electron energy spectrum is very convenient to calculate using the space radiation environment model software, and the electron temperature calculation method is simple and rapid. At the same time, it is very quick to modify the parameters in the numerical simulation experiment, and the simulation results can be quickly obtained and sorted and analyzed. In actual experiments, square targets of different densities and sizes can be easily obtained through 3D printing technology, which are ionized into plasma by pre-laser pulses. The electron beam accelerated after laser incidence is incident on the electron beam diagnostic system after passing through the magnetic focusing system. The motion trajectory of the electron on the imaging target is photographed by a CCD camera, and the energy spectrum and divergence of the electron beam can be analyzed. The method and system for simulating the space orbit electron radiation environment proposed by the present invention can provide a solution for ground simulation of different orbit electron radiation. At the same time, the method has a simple process and fast calculation, and can quickly provide various parameters of the laser and the target.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A system for simulating the electron radiation environment of a space orbit, characterized in that: The system includes a femtosecond laser system, a vacuum chamber, an optical system, a composite target, a focusing magnetic field, a beam detector and an electronic spectrometer; The composite target, focusing magnetic field, beam detector and electron spectrometer are all arranged in a vacuum chamber; The femtosecond laser system generates a beam of femtosecond laser, which is modulated by an optical system for transmission and focusing of the femtosecond laser. The modulated femtosecond laser is injected into a vacuum target chamber to ionize atoms of a composite target into plasma, and an accelerated electron beam is formed under the combined action of laser ponderomotive force or surface ponderomotive force acceleration and J×B heating mechanism. The electron beam is injected into a beam current monitor after passing through a focusing magnetic field to obtain information on the charge amount and divergence angle of the electrons, and then an energy spectrum of the electron beam is obtained through an electron spectrometer, thereby realizing ground simulation of electron radiation environments of different orbits in space; The composite target is T-shaped, including a target I and a target II which are arranged perpendicular to each other, and the incident direction of the femtosecond laser is parallel to the target I.

2. A system for simulating space orbit electron radiation environment according to claim 1, characterized in that: The target I is an aerogel target or a carbon nanotube target whose density and length can be adjusted; the target II is a solid aluminum target or a hydrocarbon target.

3. A system for simulating space orbit electron radiation environment according to claim 2, characterized in that: Aerogel targets I with different densities and lengths were obtained using 3D printing technology and combined with solid aluminum target II using an adhesive.

4. A system for simulating space orbit electron radiation environment according to claim 2, characterized in that: The electron number density of target I is 5×10 19 cm -3 ~1.1×10 22 cm -3 , length is 1μm~8μm, width is 0.1μm~1μm; The electron number density of target II is 2×10 22 cm -3 ~3×10 23 cm -3 , length is 20μm~200μm, width is 10μm~80μm.

5. The system for simulating space orbit electron radiation environment according to claim 1, characterized in that: The beam detector and the electronic spectrometer are both connected to a computer.

6. The system for simulating space orbit electron radiation environment according to claim 1, characterized in that: The focusing magnetic field is a magnet.

7. The system for simulating space orbit electron radiation environment according to claim 1, characterized in that: The composite target is arranged in a vacuum target chamber and is used to fix the combined target I and target II.

8. The system for simulating space orbit electron radiation environment according to claim 1, characterized in that: The normalized intensity of the femtosecond laser is 2.8-4.7, corresponding to a peak power of 1×10 19 W / cm 2 ~3×10 19 W / cm 2 , the pulse length is 20fs~80fs, and the focal spot radius is 3μm~8μm.

9. A method for simulating the electron radiation environment of a space orbit, characterized in that: The test is carried out using a system for simulating a space orbit electron radiation environment as described in any one of claims 1 to 8, comprising the following steps: Acquire target orbit information to obtain electron energy spectrum information corresponding to the target orbit; the electron energy spectrum information corresponding to the target orbit includes electron temperature and electron cutoff energy; Under the condition of fixing the laser parameters and target II parameters, the density and length information of target I are changed, the energy and number information of the electron beam generated after target II are collected, and the energy spectrum information of the electron beam and its corresponding electron temperature and electron cutoff energy are obtained; When the electron temperature and electron cutoff energy obtained by adjusting the density and length information of target I match the electron energy spectrum information corresponding to the target orbit, the electron radiation environment of the target orbit is obtained.

10. The method for simulating space orbit electron radiation environment according to claim 9, characterized in that: Obtain target orbital information and obtain the electronic energy spectrum information corresponding to the target orbital, specifically: Obtain the perigee and apogee heights, inclination, and running time of the target orbit, and use the AE8 or AE9 model to calculate the electron energy spectrum of the target orbit. Directly obtaining the electron cutoff energy of the target orbit according to the electron energy spectrum of the target orbit; According to the electron energy spectrum of the target orbit, the electron temperatures of the low energy segment and the high energy segment are calculated respectively.

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