Magnetic control of a Field Reversed Configuration

The Field Reversed Configuration (FRC) is a highly diamagnetic plasma confinement device used in nuclear fusion research. FRC’s exhibit an internal region of weak magnetic field with ideal conditions to reach the high temperature required to burn high Z aneutronic fuels, such as proton-boron 11 (pB11), with low synchrotron radiation losses. Improving the stability and thermal properties of a high-density fusion machine based on the FRC concept requires its plasma size to be maximized and accommodated to a long confinement vessel, but this comes at a cost. The external field required to elongate the plasma results in an axially unstable behavior that demands active feedback control. Here we show how the Norm device – an FRC fusion research facility built and operated by TAE Technologies, Inc. – uses external magnetic coil actuators to modify the plasma shape and actively stabilize the position of a long plasma while sculpting its shape in real-time. The FRC, once believed to be able to operate only in pulse mode, can now be controlled and operated continuously in steady state, as required for a high-power density fusion plasma core.