Scaled Experiment to Investigate Auroral Kilometric Radiation Mechanisms in the Presence of Background Electrons
Scaled Experiment to Investigate Auroral Kilometric Radiation Mechanisms in the Presence of Background Electrons
复制标题
研究背景电子存在下的极光千米辐射机制的规模化实验
DOI：
10.1088/1742-6596/511/1/012061
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
McConville S
中科院分区：
文献类型：
--
作者：
McConville S
极光千米辐射（AKR）发生在地球磁层极地区域的极光密度腔中，频率约为300 kHz，在X模式下极化，效率约为1-2%[1，2]，地球表面上方约3200 km的低密度等离子体区域，电子在受到磁压缩的同时加速朝向地球。由于这种磁压缩，电子在速度空间中获得马蹄形分布函数。以前的理论研究已经预测，这种分布是能够驱动回旋脉塞不稳定性。为了测试这一理论，构建了一个缩放的实验室实验，以在受控环境中复制这种现象[3-5]，同时还进行了2D和3D模拟，以预测实验辐射功率和模式[6-9]。该实验在微波频率范围内进行，并结合了一个磁场不断增加的区域，该区域位于地球的极点，使用磁铁来包裹圆柱形相互作用波导，通过该波导，初始直线电子束（12 A）被75 keV脉冲加速。实验结果表明，马蹄形分布函数的形成的证据。在4.42 GHz处，在接近截止的TE 01模式下产生辐射，与X模式特性相当。测得峰值微波输出功率约为35 kW，峰值发射效率约为2%，[3]。一个潘宁阱被构造并插入到相互作用波导中，以使背景等离子体的产生能够与磁层条件进行更密切的比较。初步设计和测量显示新的几何形状的主要特点。
Auroral Kilometric Radiation (AKR) emissions occur at frequencies~ 300kHz polarised in the X-mode with efficiencies~ 1-2%[1, 2] in the auroral density cavity in the polar regions of the Earth's magnetosphere, a region of low density plasma~ 3200km above the Earth's surface, where electrons are accelerated down towards the Earth whilst undergoing magnetic compression. As a result of this magnetic compression the electrons acquire a horseshoe distribution function in velocity space. Previous theoretical studies have predicted that this distribution is capable of driving the cyclotron maser instability. To test this theory a scaled laboratory experiment was constructed to replicate this phenomenon in a controlled environment,[3-5] whilst 2D and 3D simulations are also being conducted to predict the experimental radiation power and mode,[6-9]. The experiment operates in the microwave frequency regime and incorporates a region of increasing magnetic field as found at the Earth's pole using magnet solenoids to encase the cylindrical interaction waveguide through which an initially rectilinear electron beam (12A) was accelerated by a 75keV pulse. Experimental results showed evidence of the formation of the horseshoe distribution function. The radiation was produced in the near cut-off TE 01 mode, comparable with X-mode characteristics, at 4.42 GHz. Peak microwave output power was measured~ 35kW and peak efficiency of emission~ 2%,[3]. A Penning trap was constructed and inserted into the interaction waveguide to enable generation of a background plasma which would lead to closer comparisons with the magnetospheric conditions. Initial design and measurements are presented showing the principle features of the new geometry.
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用于极光千米辐射实验室模拟的电子束测量
影响因子：
3.8
作者：
K. Ronald;S. McConville;D. Speirs;A. Phelps;C. Robertson;C. Whyte;Wenlong He;K. Gillespie;A. Cross;R. Bingham
通讯作者：
R. Bingham
影响因子：
2.2
作者：
D. Speirs;S. McConville;K. Gillespie;K. Ronald;A. Phelps;A. Cross;R. Bingham;C. Robertson;C. Whyte;I. Vorgul;R. A. Cairns;B. Kellett
通讯作者：
D. Speirs;S. McConville;K. Gillespie;K. Ronald;A. Phelps;A. Cross;R. Bingham;C. Robertson;C. Whyte;I. Vorgul;R. A. Cairns;B. Kellett
用于极光千米辐射实验室模拟的射频谐振器结构和诊断测量
影响因子：
2.2
作者：
K. Ronald;D. Speirs;S. McConville;A. Phelps;C. Robertson;C. Whyte;Wenlong He;K. Gillespie;A. Cross;R. Bingham
通讯作者：
R. Bingham
空间和实验室等离子体中的回旋脉泽辐射
影响因子：
1.6
作者：
R. Bingham;B. Kellett;R. A. Cairns;I. Vorgul;A. Phelps;K. Ronald;D. Speirs
通讯作者：
D. Speirs
回旋脉泽不稳定性及其在空间和实验室等离子体中的应用
影响因子：
2.9
作者：
R. A. Cairns;D. Speirs;K. Ronald;I. Vorgul;B. Kellett;A. Phelps;R. Bingham
通讯作者：
R. Bingham