System for simulating space orbit electron radiation environment
By combining a composite structure target with a femtosecond laser, the problem that traditional devices cannot produce low-energy exponential electron beams was solved, and ground simulation of the space orbit electron radiation environment was achieved, providing theoretical guidance and low-cost multi-environment adaptation.
Patent Information
- Application Number
- CN202422793674.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-15
- Publication Date
- 2025-10-10
- Estimated Expiration
- 2034-11-15
AI Technical Summary
Existing space radiation environment simulation devices based on traditional accelerators cannot produce exponentially wide-spectrum electron beams below 10MeV, and the method of directly bombarding high-density solid targets with lasers has high requirements for laser focusing and large divergence, making it difficult to control the electron beam energy spectrum.
A composite structure target is used, including vertically arranged targets I and II, combined with a femtosecond laser generating device, a vacuum chamber, an optical system, a magnet, a beam detector and an electron spectrometer. An accelerated electron beam is formed through the interaction between the femtosecond laser and the composite target, and energy spectrum analysis is performed using a focused magnetic field and an electron spectrometer. The density and length of target I are adjusted to match the electron radiation environment of different orbits.
It realizes the ground simulation of electron radiation environments in different orbits, provides a theoretical analysis model, reduces production costs, and can adapt to the simulation of various complex environments, simplifying the target material production process.
Smart Images
Figure CN223426871U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to novel particle acceleration technology and space radiation environment technical field, especially, relate to a system of simulating space orbit electron radiation environment. BACKGROUND
[0002] Under the influence of the geomagnetic field, there are a large number of electrons with energy less than 10 MeV in the Earth's radiation belt. The energy spectrum structure of these electrons after accumulation presents a nearly exponential distribution, with the characteristics of wide energy spectrum. At present, the space radiation environment simulation device based on the traditional accelerator cannot produce such electron beams, so there are problems such as space radiation simulation equivalence, and it is difficult to accurately characterize the radiation effects of space particles. The rapid development of laser accelerators provides an effective method for the generation of wide energy spectrum electron beams, for example, it is relatively easy to produce exponential wide energy spectrum electron beams by using an ultrahigh laser with a focused power density of 10 18 -10 20 W / cm 2 .
[0003] At present, the research on space electron radiation environment simulation based on laser particle accelerators is mostly achieved by directly bombarding high-density solid targets with lasers. This method has high requirements for laser focusing, the energy spectrum structure of the generated electron beams is difficult to control, the divergence is large, and a high laser energy is required.
[0004] Therefore, there is an urgent need in the industry for a new type of system for simulating space orbit electron radiation environment. UTILITY MODEL CONTENT
[0005] To solve the problems existing in the prior art, the utility model provides a system for simulating space orbit electron radiation environment, which uses a composite structure target to compensate for the blank of space electron radiation environment simulation in different radiation environments of multiple orbits, and has important significance for conducting space radiation effect research on the ground.
[0006] To achieve the above purpose, the utility model provides a system for simulating space orbit electron radiation environment,
[0007] The system comprises a femtosecond laser generating device, a vacuum chamber, an optical system, a composite target, a magnet for generating a focusing magnetic field, a beam detector for obtaining charge information and divergence angle information of the electron beam, and an electron spectrometer.
[0008] The composite target, the focusing magnetic field, the beam detector and the electron spectrometer are all arranged in the vacuum chamber.
[0009] The composite target is T-shaped and comprises target I and target II arranged perpendicularly to each other.
[0010] The femtosecond laser generating device is used to generate a femtosecond laser. After the femtosecond laser is injected into the optical system, a modulated femtosecond laser is obtained. The modulated femtosecond laser is first injected parallel to target I in the composite target, and then injected vertically into target II. The femtosecond laser interacts with the composite target to obtain an accelerated electron beam. After passing through a focusing magnetic field, the electron beam is sequentially injected into a beam detector and an electron spectrometer.
[0011] Furthermore, target I in the composite target is combined with target II via an adhesive.
[0012] Furthermore, the target I is an aerogel target or a carbon nanotube target whose density and length can be adjusted.
[0013] Furthermore, the target II is a solid aluminum target or a hydrocarbon target.
[0014] 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, and width is 0.1μm~1μm.
[0015] Furthermore, 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.
[0016] Furthermore, the femtosecond laser generating device includes a laser, a filter and a compression amplifier connected in sequence.
[0017] Furthermore, the normalized intensity of the femtosecond laser is 2.8 to 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] Furthermore, the beam detector and the electronic spectrometer are both electrically connected to a computer for exporting simulation experiment data.
[0019] Furthermore, the composite target is arranged in a vacuum target chamber to fix the combined target I and target II.
[0020] Furthermore, 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:
[0021]
[0022] Where ξ = x-ct is the co-moving coordinate, r is the lateral distance from the optical axis, the laser pulse width τ0 = 40 fs, and the focal spot radius σ0 = 5 μm.
[0023] Furthermore, the optical system includes an optical transmission device and a laser focusing device.
[0024] The utility model has the following beneficial effects:
[0025] 1. The present invention provides a system for simulating the electron radiation environment in space orbits, the system comprising a femtosecond laser generating device, a vacuum chamber, an optical system, a composite target, a magnet for generating a focusing magnetic field, a beam detector, and an electron spectrometer; the composite target, focusing magnetic field, beam detector, and electron spectrometer are all arranged in the vacuum chamber; the composite target is T-shaped, comprising a target I and a target II arranged perpendicular to each other; the femtosecond laser generating device is used to generate a femtosecond laser, which is injected into the optical system to obtain a modulated femtosecond laser, which is first injected into target I in the composite target in parallel and then injected into target II perpendicularly, ionizing the atoms of the composite target into plasma and forming an accelerated electron beam under the combined action of laser ponderomotive force or surface ponderomotive force acceleration and J×B heating mechanism, and after passing through the focusing magnetic field, the electron beam is first injected into the beam detector to obtain the charge and divergence angle information of the electron beam, and then injected into the electron spectrometer to obtain the energy spectrum of the electron beam, thereby realizing ground-based simulation of the electron radiation environment in different space orbits. Especially under the conditions of fixed laser parameters and unchanged target II parameters, by adjusting the density and length information of target I, an electron beam that adapts to the electron energy spectrum of different orbits in space can be obtained, and then the electron radiation environment of different orbits in space can be simulated, 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.
[0026] 2. The space radiation environment varies significantly at orbits of different altitudes. This utility model utilizes laser particle acceleration to simulate electron radiation in different orbits, enabling the simulation of a variety of complex environments at a relatively low cost. By utilizing variations in the electron acceleration mechanism in plasmas of varying densities and controlling target length, the electron energy spectrum can be manipulated to match the radiation environment of different orbits. Furthermore, this utility model provides a target design for ground-based simulation of electron radiation at orbits of varying altitudes. The target is simple and easy to manufacture, helping to reduce target material production costs.
[0027] 3. The system for simulating the space orbit electron radiation environment proposed in this utility model can not only provide analytical guidance for ground simulations of different orbit electron radiation environments and help experiments select target types 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.
[0028] 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 below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:
[0030] Figure 1 This is a schematic structural diagram of a system for simulating space orbit electron radiation environment provided by the utility model;
[0031] Figure 2 This is a schematic diagram of a composite target in a system for simulating space orbit electron radiation environment provided by the utility model;
[0032] Figure 3 This is a parameter diagram of a composite target in a system for simulating a space orbit electron radiation environment provided by the utility model;
[0033] Among them, 1. Femtosecond laser generating device, 2. Optical system, 3. Composite target, 4. Magnet, 5. Beam detector, 6. Electronic spectrometer, 7. Computer, 8. Vacuum chamber, 9. Vacuum target chamber, 31. Target I, 32. Target II. DETAILED DESCRIPTION
[0034] The following describes the embodiments of the present invention in detail with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered by the claims.
[0035] like Figures 1 to 3 As shown, the present invention provides a system for simulating the electron radiation environment of a space orbit, the system comprising a femtosecond laser generating device 1, a vacuum chamber 8, an optical system 2, a composite target 3, a magnet 4 for generating a focusing magnetic field, a beam detector 5 for obtaining information on the charge amount and divergence angle of an electron beam, and an electron spectrometer 6;
[0036] The composite target 3, focusing magnetic field, beam detector 5 and electron spectrometer 6 are all arranged in a vacuum chamber 8;
[0037] The composite target 3 is T-shaped and includes a target I 31 and a target II 32 that are perpendicular to each other;
[0038] The femtosecond laser generating device 1 is used to generate a femtosecond laser. After entering the optical system 2, the femtosecond laser is modulated. The modulated femtosecond laser is first incident parallel to target I 31 in the composite target 3 and then incident perpendicularly to target II 32. This ionizes the atoms of the composite target 3 into a plasma. Under the combined action of laser ponderomotive force or surface ponderomotive force acceleration and J×B heating, an accelerated electron beam is formed. After passing through a focusing magnetic field, the electron beam is first incident on a beam detector 5 to obtain information on the electron beam's charge and divergence angle, and then incident on an electron spectrometer 6 to obtain its energy spectrum, thereby enabling ground-based simulation of electron radiation environments at different orbits in space. Specifically, under the conditions of fixed laser parameters and target II 32 parameters, by adjusting the density and length of target I 31, an electron beam adapted to the electron energy spectrum at different orbits in space can be obtained, thereby simulating the electron radiation environment at different orbits in space. This fills a gap in the field of ground-based simulation of space radiation environments at different orbits and provides a theoretical analysis model for subsequent experimental work, thus providing certain guiding significance.
[0039] In a specific embodiment, the femtosecond laser generating device 1 includes a laser, a filter and a compression amplifier connected in sequence, which are used to provide femtosecond lasers of different intensities and pulse widths. The optical system 2 includes an optical transmission device and a laser focusing device, which are used to modulate the focal spot and angle 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 31 and the target II 32; the magnet 4 is used to generate a focusing magnetic field to focus the accelerated electron beam; the beam detector 5 obtains the charge amount and divergence angle information of the electron beam, and the electron spectrometer 6 obtains the energy spectrum of the electron beam. The beam detector 5 and the electron spectrometer 6 are both electrically connected to a computer 7 for deriving simulation experimental data.
[0040] In one specific embodiment, target I is an aerogel target or carbon nanotube target with adjustable density and length; plasma target II is a high-density solid aluminum target or hydrocarbon target. Aerogel targets I of varying density and length are produced using 3D printing technology and combined with solid aluminum target II using an adhesive. The electron beam energy information described in this utility model can be obtained using a beam detector and an electron spectrometer and can be rapidly derived using a computer in numerical simulation experiments. Target I is made of aerogel, and current 3D printing technology can produce square targets of specific density and length.
[0041] 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.
[0042] The normalized intensity of the 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:
[0043]
[0044] Where ξ = x-ct is the co-moving coordinate, r is the lateral distance from the optical axis, the laser pulse width τ0 = 40 fs, and the focal spot radius σ0 = 5 μm.
[0045] The laser electron acceleration experiment in the present invention is specifically as follows: a femtosecond laser generating device generates a beam of linearly polarized femtosecond laser, the femtosecond laser focal spot and angle are modulated by 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.
[0046] The utility model provides a 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 the density and size of target I and target II in the combined target, an electron beam with a specific energy distribution is generated to match the space electron radiation energy spectrum of the target orbit. Specifically, after determining the target orbit information, the electron energy spectrum is calculated to obtain the electron temperature at the low energy end and the high energy end, and the laser intensity, focal spot radius, pulse width and the density and size of target I and target II are determined to obtain an electron beam that matches the electron radiation energy spectrum of the target orbit. Through a two-dimensional particle simulation experiment, specific laser and target parameters are selected to obtain an electron beam that matches the electron energy spectrum of the target orbit. The degree of matching between the electron energy spectrum structure obtained by simple calculation and analysis and the electron energy spectrum of the target orbit is good, and combined with theory, it is found that for target I with an electron number density less than n e=1×10 20 cm -3 In the case of laser ponderomotive force, the electron acceleration mechanism is dominated by the laser ponderomotive force. As the electron number density increases, the electron acceleration mechanism gradually transitions from laser ponderomotive force to surface ponderomotive force. At this point, the length of Target I is positively correlated with the maximum energy of the accelerated electrons. By switching between these two acceleration mechanisms, the electron beam energy spectrum structure, electron temperature, and maximum energy obtained by targets I of different densities and lengths can be effectively controlled, thereby achieving a result that closely matches the electron energy spectrum of the target orbit.
[0047] The present invention is further explained and illustrated below in conjunction with specific implementation methods.
[0048] The use of this system is based on the ground simulation of different orbit electron radiation environments based on laser particle acceleration using the two-dimensional particle simulation software LAPINE. In order to control the variables, the same solid aluminum target II and electron number density n are set. e =6.6×10 22 cm -3 , thickness D = 10 μm, width L = 30 μm, initial target I electron number density n e =1.1×10 20 cm -3 , the thickness is d = 1 μm, the length is l = 3 μm, and the initial laser normalized intensity a0 = 3.2 is set. The incident laser propagates along the x-axis and is polarized along the y-axis. Both the transverse and longitudinal directions are Gaussian pulses. The laser field intensity expression is:
[0049]
[0050] Where ξ = x-ct is the co-moving coordinate, r is the lateral distance from the optical axis, the laser pulse width τ0 = 40 fs, and the focal spot radius σ0 = 5 μm.
[0051] According to our initial results, the target I density is n e =5.5×10 19 cm -3 、n e =1.1×10 20 cm -3 、n e =3.3×10 20 cm -3 、n e =5.5×10 20 cm -3 、n e =1.1×10 21 cm -3, with lengths of l = 1 μm, l = 3 μm, l = 5 μm, and l = 8 μm, respectively. The two-dimensional particle simulation software LAPINE was used to calculate the various parameters and organize the initial data. A simulation window of 40 μm × 30 μm was selected to reduce unnecessary calculations. The grid was divided into 8000 × 2000 grids, each containing 20 macroparticles, each representing 5000 electrons or ions.
[0052] By calculating the electron temperature and maximum electron energy, we first determined the universality of this scheme for the electron radiation environment in the Van Allen inner radiation belt (orbital altitude of 600-10000km). The maximum electron energy is concentrated within 8MeV, and the electron temperature is concentrated in the range of 0.4-0.62MeV. The selected initial parameters can meet the simulation calculation within this range.
[0053] This utility model can generate femtosecond laser pulses by selecting different lasers and configuring the optical system. Aerogel targets I of varying densities and lengths are produced using 3D printing technology and then combined with a solid aluminum target or hydrocarbon target II using an adhesive. The electron beam accelerated by the laser passes through a magnetic focusing system and is then incident on a beam detector and electron spectrometer, allowing analysis of information such as the energy spectrum and angular divergence of the electron beam.
[0054] The space radiation environment varies significantly at orbits of different altitudes. Simulating electron radiation in different orbits using laser particle acceleration can achieve the simulation of a variety of complex environments at a relatively low cost. By utilizing the variations in the electron acceleration mechanism in plasmas of varying densities and controlling the target length, the electron energy spectrum can be manipulated to match the electron radiation environment of different orbits. By analyzing the electron temperature in different orbits and statistically analyzing the changes in electron temperature, the density and length parameters of Target I are adjusted to ensure that the electron beam generated by the interaction between the laser and the target matches the electron radiation environment of a given orbit.
[0055] This utility model proposes a system for simulating the electron radiation environment in space orbits. By adjusting the density and length of Target I while keeping the laser parameters and target II parameters constant, an electron beam tailored to the energy spectrum of electrons in different orbits in space can be obtained. This system fills a gap in the field of space radiation environment simulation for ground-based simulations of different orbits and provides a theoretical analysis model for subsequent experimental work, which has certain guiding significance. This utility model method can provide a target design scheme for ground-based simulation of electron radiation in space orbits of different altitudes. The target is simple and easy to manufacture, which helps to control the cost of target material production.
[0056] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection 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 generating device, a vacuum chamber, an optical system, a composite target, a magnet for generating a focusing magnetic field, a beam detector for obtaining information on the charge amount and divergence angle of the electron beam, and an electron spectrometer; The composite target, focusing magnetic field, beam detector and electron spectrometer are all arranged in a vacuum chamber; The composite target is T-shaped and includes target I and target II arranged perpendicular to each other; The femtosecond laser generating device is used to generate a femtosecond laser. After the femtosecond laser is injected into the optical system, a modulated femtosecond laser is obtained. The modulated femtosecond laser is first injected parallel to target I in the composite target, and then injected vertically into target II. The femtosecond laser interacts with the composite target to obtain an accelerated electron beam. After passing through a focusing magnetic field, the electron beam is sequentially injected into a beam detector and an electron spectrometer.
2. The system for simulating space orbit electron radiation environment according to claim 1, characterized in that: Target I in the composite target is combined with target II via a binder.
3. The 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.
4. The system for simulating space orbit electron radiation environment according to claim 1, characterized in that: The target II is a solid aluminum target or a hydrocarbon target.
5. The system for simulating space orbit electron radiation environment according to claim 1, 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, and width is 0.1μm~1μm.
6. The system for simulating space orbit electron radiation environment according to claim 1, characterized in that: 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.
7. The system for simulating space orbit electron radiation environment according to claim 1, characterized in that: The femtosecond laser generating device comprises a laser, a filter and a compression amplifier which are connected in sequence.
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. 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 electrically connected to the computer.
10. 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.