Using X-rays to Measure Electric Currents

Advisors: Anna Malanushenko and Dana Longcope

When the viewed in X-rays or extreme ultraviolet (EUV) the Sun's outer atmosphere, the corona, consists of many thin strands called loops. Loops are believed to trace out a few of the magnetic field lines which fill up the entire corona. While the X-ray images do not provide direct measurements of current flowing within the magnetic field, their shapes can be used to infer current indirectly. The loops are traced on a computer screen and these curves are compared to the shapes of field lines with a range of different currents. The best fitting field line provides an estimate of the current in the coronal field.

The student will apply the iterative fitting method to an archive of X-ray or EUV data from spacecrafts. One goal of the work is to measure changes in current as the magnetic field changes. The student should have studied electromagnetism and have some experience working with computers. Previous knowledge of IDL is desirable, but not required.