Implicit Conservative Particle-In-Cell Kinetic Simulations of Magnetic Nozzles

The plasma in a magnetic nozzle is essentially collisionless and quasineutral. In this regime, general closure relations for the electron fluid equations currently do not exist, and closure choice determines central device features such as the electron cooling, electrostatic potential, and magnetic thrust. Often, polytropic laws [1] are invoked without much physical justification, offering a free parameter that can be fitted to experimental results, with mixed success.