Measurement of Magnetic Field in Magnetic Reconnection Experiments Using Proton Radiographs coupled with an In-Situ X Ray Reference

Experiments at the NIF and OMEGA laser facilities are used to understand magnetic reconnection for the applications of laboratory astrophysics and fusion. At these facilities, a laser target interaction is used to produce two plasma plumes with reversed magnetic fields due to the Biermann battery effect. The collision of the two plasma plumes drives an interesting phenomenon known as magnetic reconnection where magnetic energy is stored in the cross section of the reversing magnetic fields and released in a sling-shot motion driven by the magnetic forces. Proton radiography with a mesh is used to measure the magnetic fields during reconnection by differencing proton deflection images (of 3MeV and 15 MeV produced by a fusion implosion) with the undeflected mesh image generated by x-ray imaging. The undeflected mesh image is a recent addition to magnetic reconnection experiments that yields increased precision for proton radiography and 2D topology of magnetic fields. These results measure the profiles of the magnetic field undergoing reconnection for comparison with simulations and previous experiments.