基于AKEBONO哨声波参数的内辐射带高能电子扩散模拟
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摘要
为能准确地模拟内辐射带中哨声波对高能电子扩散损失的影响,基于内辐射带AKEBONO哨声波参数统计模型,及随纬度分布的背景冷等离子体密度模型,对引起电子扩散损失的大气分子,空间等离子体嘶声、闪电激发的哨声、人工激发的甚低频三类哨声波,利用准线性扩散理论,计算1.4≤L≤2.0区域的不同能量电子,受到库仑碰撞和波粒回旋共振相互作用的弹跳周期平均赤道投掷角扩散系数,分析不同作用机制、不同类哨声波、不同能量、不同磁壳参数等对辐射带高能电子扩散损失的影响.结果表明:在赤道面损失锥角附近,高能电子主要受到库仑碰撞作用而扩散;在赤道投掷角接近90°附近区域,等离子体嘶声和闪电激发的哨声是引起扩散的主要因素;内辐射带电子主要受到甚低频电磁波波粒回旋共振扩散影响;扩散系数对高能电子能量及其所处磁壳参数比较敏感,通常,高能电子的能量或所处磁壳参数越大,扩散系数越大.
With inner radiation belt AKEBONO whistle wave parameter statistics model and background cold electron density model changed with altitude,as 1. 4 ≤ L ≤ 2. 0 electron bounce-averaged equator pitch angle diffusion coefficients due to Coulomb collision and wave-particle resonance interaction are calculated by using quasi-linear diffusion theory. Influences of interaction mechanisms,whistle wave types such as hiss,lightning-generated whistlers( LG),artificial very low frequency( VLF),energies and magnet shell parameter( L) on inner radiation belt energetic electrons diffusing loss are analyzed. It shows that Coulomb collision caused by atmosphere plays a dominant role in energetic electrons diffusion around equator loss cone angle,while hiss and LG are main diffusion factors near 90° of equator pitch angle. Wave-particle resonance diffusion caused by VLF plays a dominant role in inner radiation belt.Diffusion coefficients is sensitive to energetic electron energy and L. Usually,the greater the L or electron energy,the more significant the electron resonance diffusion coefficient is.
With inner radiation belt AKEBONO whistle wave parameter statistics model and background cold electron density model changed with altitude,as 1. 4 ≤ L ≤ 2. 0 electron bounce-averaged equator pitch angle diffusion coefficients due to Coulomb collision and wave-particle resonance interaction are calculated by using quasi-linear diffusion theory. Influences of interaction mechanisms,whistle wave types such as hiss,lightning-generated whistlers( LG),artificial very low frequency( VLF),energies and magnet shell parameter( L) on inner radiation belt energetic electrons diffusing loss are analyzed. It shows that Coulomb collision caused by atmosphere plays a dominant role in energetic electrons diffusion around equator loss cone angle,while hiss and LG are main diffusion factors near 90° of equator pitch angle. Wave-particle resonance diffusion caused by VLF plays a dominant role in inner radiation belt.Diffusion coefficients is sensitive to energetic electron energy and L. Usually,the greater the L or electron energy,the more significant the electron resonance diffusion coefficient is.
引文
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[13]LYONS L R.Pitch angle and energy diffusion coefficients from resonant interactions with ion-cyclotron and whistler waves[J].Journal of Plasma Physics,1974,12:417-432.
[14]GLAUERT S A,HORNE R B.Calculation of pitch angle and energy diffusion coefficients with the PADIE code[J].Journal of Geophysical Research,2005,110:A04206.
[15]CHEN F F.等离子体物理学导论[M].北京:人民教育出版社,1980.
[16]SCHULZ M,LANZEROTTI L J.Particle diffusion in the radiation belts[M].New York:Springer-Verlag Press,1974.
[17]WALT M.Introduction to geomagnetically trapped radiation[M].London:Cambridge University Press,1994.
[18]LYONS L R,THORNE R M,KENNEL C F.Electron pitch-angle diffusion driven by oblique whistler-mode turbulence[J].Journal of Plasma Physics,1971,6(3):589-606.
[19]LYONS L R,THORNE R M,KENNEL C F.Pitch-angle diffusion of radiation belt electrons within the plasmasphere[J].Journal of Geophysical Research,1972,77(19):3455-3474.
[2]KENNEL C F,PETSCHEK H E.Limit on stably trapped particle fluxes[J].Journal of Geophysical Research,1966,71(1):1-28.
[3]ABEL B,THORNE R M.Electron scattering and loss in Earth's inner magnetosphere,1:Dominant physical processes[J].Journal of Geophysical Research,1998,103(A2):2385-2396.
[4]ABEL B,THORNE R M.Electron scattering and loss in Earth's inner magnetosphere,2:Sensitivity to model parameters[J].Journal of Geophysical Research,1998,103(A2):2397-2707.
[5]罗旭东,牛胜利,左应红.典型甚低频电磁波对辐射带高能电子的散射损失效应[J].物理学报,2015,64(06):069401.
[6]AGAPITOV O V,ARTEMYEV A V,MOURENAS D,et al.Inner belt and slot region electron lifetimes and energization rates based on AKEBONO statistics of whistler waves[J].Journal of Geophysical Research:Space Physics,2014,119:2876-2893.
[7]BAKER D N,JAYNES A N,HOXIE V C,et al.An impenetrable barrier to ultrarelativistic electrons in the Van Allen radiation belts[J].Nature,2014,515:531-534.
[8]FENNELL J F,CLAUDEPIERRE S G,BLAKE J B,et al.Van Allen Probes show that the inner radiation zone contain no Me V electrons:ECT/Mag EIS data[J].Geophysical Research Letters,2015,42:1283-1289.
[9]HORNE R B,GLAUERT S A,MEREDITH N P,et al.Space weather impacts on satellites and forecasting the Earth's electron radiation belts with SPACECAST[J].Space Weather,2013,11:169-186.
[10]OZHOGIN P,TU J,SONG P,et al.Field-aligned distribution of the plasmaspheric electron density:An empirical model derived from the IMAGE RPI measurements[J].Journal of Geophysical Research,2012,117:A06225.
[11]牛胜利,罗旭东,王建国,等.高空核爆炸注入辐射带电子的大气扩散损失[J].计算物理,2011,28(4):569-575.
[12]KENNEL C F,ENGELMANN F.Velocity space diffusion from weak plasma turbulence in a magnetic field[J].Physics of Fluids,1966,9:2377-2388.
[13]LYONS L R.Pitch angle and energy diffusion coefficients from resonant interactions with ion-cyclotron and whistler waves[J].Journal of Plasma Physics,1974,12:417-432.
[14]GLAUERT S A,HORNE R B.Calculation of pitch angle and energy diffusion coefficients with the PADIE code[J].Journal of Geophysical Research,2005,110:A04206.
[15]CHEN F F.等离子体物理学导论[M].北京:人民教育出版社,1980.
[16]SCHULZ M,LANZEROTTI L J.Particle diffusion in the radiation belts[M].New York:Springer-Verlag Press,1974.
[17]WALT M.Introduction to geomagnetically trapped radiation[M].London:Cambridge University Press,1994.
[18]LYONS L R,THORNE R M,KENNEL C F.Electron pitch-angle diffusion driven by oblique whistler-mode turbulence[J].Journal of Plasma Physics,1971,6(3):589-606.
[19]LYONS L R,THORNE R M,KENNEL C F.Pitch-angle diffusion of radiation belt electrons within the plasmasphere[J].Journal of Geophysical Research,1972,77(19):3455-3474.