Congratulations to Jason Kooi for successfully defending his PhD dissertation on "Very Large Array Faraday Rotation Studies of Coronal Plasma."

"Jason used the Very Large Array radio telescope to study the plasma (ionized gas) in the solar corona, the outermost layer of the Sun's atmosphere. Jason analyzed the corona by studying the Faraday rotation of signals from distant radio sources that propagated through the corona on the way to Earth. Jason studied one set of observations which probed the corona at heliocentric distances of less than 5 solar radii. These measurements showed the effects of coronal streamers, and provided constraints on the properties of the plasma in this part of space. In a major study, Jason measured and analyzed the Faraday rotation signals due to Coronal Mass Ejections (CMEs) that moved across the line of sight to radio sources. He showed that the measurements could be explained in terms of a theoretical plasma structure called a force-free flux tube. Finally, Jason carried out a major technical project that allows corrections for the Earth's ionosphere to be applied to Very Large Array data."
— Steven Spangler, PhD advisor

Dr. Kooi has accepted a research physicist position in the Remote Sensing Division at the U.S. Naval Research Laboratory.