The Jovian magnetodisk
The Jovian magnetodisk
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木星磁盘
DOI：
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发表时间：
1979
期刊：
影响因子：
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通讯作者：
C. K. Goertz
中科院分区：
文献类型：
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作者：
C. K. Goertz
Pioneers-10 和 11 上的矢量氦磁力计进行的磁场测量揭示了携带东向电流的电流片（厚度~2RJ）的存在。对电流片的自洽研究表明，电流的量级为 10+2 Am+1，并且电流由热 (T>1 keV) 等离子体承载，等离子体的密度在 30RJ 下的 1 cm+3 到 80RJ 下的 10+2 cm+3 之间变化。电流片在方位角上翘曲并与磁偶极子赤道平行。方位角场分量的存在表明极向等离子体流每秒将大约 1029 个离子从木星传输到外磁层。结果表明，如果外磁层处于稳定状态，则等离子体必须通过扩散过程在电流片内向外传输，该扩散过程比内磁层中负责粒子传输的扩散过程快，但比玻姆扩散慢。这表明扩散是由于在当前片中观察到的 mhd 湍流造成的。这样的模型需要存在开放场线，粒子可以沿着该开放场线自由逃逸到行星际空间。
Magnetic field measurements made by the vector helium magnetometers on board Pioneers-10 and 11 reveal the existence of a current sheet (thickness ∼2RJ) carrying an eastward current. Self-consistent studies of the current sheet show that the magnitude of the current is of the order of 10+2 Am+1 and that the current is carried by a hot (T>1 keV) plasma, the density of which varies between 1 cm+3 at 30RJ to 10+2 cm+3 at 80RJ. The current sheet is warped azimuthally and parallel to the magnetic dipole equator.The existence of an azimuthal field component indicates a poloidal plasma flow transporting some 1029 ions per second from Jupiter into the outer magnetosphere. It is shown that, if the outer magnetosphere is in a steady state, this plasma must be transported outward within the current sheet by a diffusion process which is faster than the one responsible for particle transport in the inner magnetosphere but slower than Bohm diffusion. It is suggested that the diffusion is due to the observed mhd turbulence in the current sheet. Such a model requires the existence of open field lines along which particles can escape freely into interplanetary space.