The Study of Coronal Plasma Turbulence with Radioastro- nomical Interferometers

该项目将利用无线电传播技术研究日冕和太阳风中的等离子体湍流。无线电波的来源是河外的射电源，它在很宽的频率范围内发射部分线极化辐射。这些源是用标准的射电天文仪器，如甚大阵列（VLA）和甚长基线阵列（VLBA）来观测的。当这些源通过日冕和太阳风的湍流等离子体介质观察时，可能会观察到各种扭曲或“模糊”效应。通过对这些效应的测量，可以推断出有关湍流强度、空间功率谱和物理性质的信息。在拟议拨款期内，将从两种观测中获得有关日冕湍流的资料。第一个是测量射电源在湍流介质中的角度展宽或“模糊”。这些观测将在VLA和VLBA上进行。第二类观测包括测量线早极化射电源偏振面法拉第旋转。这些观测将与VLA一起进行，并将提供有关日冕磁场变化以及密度变化的信息。最后，将日冕等离子体波特性与射电天文观测联系起来进行理论研究。＃

This project will study plasma turbulance in the solar corona and solar wind using radio propagation techniques. The sources of the radio waves are extragalactic radio sources which emit partially linearly polarized radiation over a wide frequency range. The sources are observed with standard radioastronomical instruments such as the Very Large Array (VLA) and Very Long Baseline Array (VLBA). When these sources are viewed through the turbulent plasma medium of the corona and solar wind, various distortion or "blurring" effects may be observed. From measurements of these effects, information about the intensity, spatial power spectrum, and physical nature of the turbulence can be deduced. During the proposed grant period information on coronal turbulence will be obtained from two types of observation. The first is a measurement of angular broadening or "blurring" of a radio source viewed through a turbulent medium. These observations will be carried out with the VLA and VLBA. The second type of observation consists of measurement of Faraday Rotation of the plane of polarization of alinearly polarized radio source. These observations will be made with the VLA and will provide information on variations in the magnetic field in the corona as well as density variations. Finally, theoretical work will be made which relates radioastronomical observables to properties of coronal plasma waves. #