2D Field Loop Advection

Background on the problem

For Background and problem setup see ​http://www.astro.virginia.edu/VITA/ATHENA/field-loop.html

And for a movie of what the solution should look like see ​http://www.youtube.com/watch?v=ztaoT1yPloc

Details of test

This test is run in order to verify that the ConstrainedTransport method to evolve magnetic fields is working correctly.

Since this problem should evolve in a well-defined way, any major deviations from this evolution signal a possible bug somewhere in one or more of the integration schemes.

Results

The new chombo can be verified by looking at the magnitude of the magnetic field in the x-direction. You should see that the field loop has advected to the right, and is rotating counter-clockwise as shown by the reference chombo.

Reference Chombo	New Chombo
	???

​Test Log