Permanent Magnet Mirror

Advances in permanent magnet technology may enable their usage as a simple and accessible option for fusion mirror configurations. Permanent magnets do not require power supplies or cryogenic cooling, and are conveniently adjustable, demountable, and low-cost. Attaining high magnetic field strengths is challenging, though, since the maximum remanent magnetization of the evaluated neodymium boron iron permanent magnets (NdFeB) is 1.4 Tesla. However, by implementing a judicious configuration, we are able to demonstrate a magnetic mirror with field maxima of 5 Tesla. Producing magnetic fields exceeding this strength would begin to demagnetize the permanent magnets at room temperature. The configuration is built from analytic optimized solutions, which can be utilized to generate mirror devices with different geometries and parameters. Possible applications of the theoretical configurations range from plasma confinement in stellarators to medical imaging devices, and will be discussed during the presentation.