Studies of the Solar Wind Near the Sun

20ro内的太阳风等离子体将使用各种无线电传播技术进行研究。这样就可以估计密度波动的空间谱、平均流速、其随机分量和磁场的方向。这些测量结果将与光学数据进行比较，如白光日冕仪、磁力计和发射线观测。研究的基本目标是进一步了解日冕加热机制和临界点附近的能量流动，并研究快速流等大尺度结构的日冕起源。早前的观测表明，在20ro内，随机速度迅速增加，在10至300公里尺度上的密度波动功率过大，密度波动变得高度各向同性。本研究将利用多天线强度闪烁测量粒子通过声波点的加速度。空间各向异性作为空间尺度的函数将通过比较角散射（在VLA测量）和相位闪烁（用VLBA测量）来测量。将分析强度闪烁，以了解随机速度分量的来源。最后，20 Ro内的观测结果可以比远离太阳的观测结果更准确地与地面测量结果进行比较，因为测绘距离很小，流-流相互作用的重要性要小得多。将研究确定不同磁几何区域之间流场的差异。

The solar wind plasma within 20 Ro will be studied using a variety of radio propagation techniques. This will permit estimation of the spatial spectrum of density fluctuations, the mean flow velocity, its random component and the orientation of the magnetic field. These measurements will be compared with optical data, such as white light coronograph, magnetograph, and emission line observations. The basic objectives will be to learn more about the mechanism of coronal heating and the flow of energy near the critical point, and to study the coronal origin of large scale structures such as fast streams. Within 20 Ro earlier observations have shown a rapid increase in random velocity, excess power in density fluctuations on scales of 10 to 300 km, and density fluctuations which become highly isotropic. This study will measure the acceleration of the particles through the sonic point using multiple antenna intensity scintillations. The spatial anisotropy as a function of spatial scale will be measured by comparing angular scattering (measured at the VLA) with phase scintillation (measured with the VLBA). The intensity scintillations will be analyzed to learn the origin of the random velocity component. Finally, observations within 20 Ro can be compared with surface measurements more accurately than those further from the sun because the mapping distance is small and stream-stream interactions are much less important. A study will be made to determine the difference in the flow field between regions of different magnetic geometry.