Study of the conversion of magnetic energy to plasma kinetic energy during guide field magnetic reconnection in MRX

We have studied the conversion of the magnetic energy to the plasma kinetic energy and the associated particle dynamics during guide field reconnection in the laboratory. The upstream reconnecting magnetic field is comparable to the guide field. The electron flow along the separatrices towards the electron diffusion region (EDR) is observed to be faster than the outflow velocity. The parallel electric field E_||, energizes inflowing electrons near the separatrices outside the EDR. The majority of the power deposition on electrons occurs in the EDR by E_||. The electron dynamics in the ion diffusion region (IDR) sets up a perpendicular electric field E_⊥ by the (v_e × B) term of Ohm's law. This E_⊥ energizes ions in the regions of IDR where plasma density is enhanced. These high-density regions are part of a quadrupolar density structure that pervades the IDR. The spatial extent of the E_⊥ structure driving the ion energization is comparable to the ion gyroradius and the ion acceleration is ballistic like. Energy partition calculation shows 40% of the magnetic energy is converted to particle energy, 67% of which is transferred to ions and 33% to electrons.