Columbia's Relativistic Electron Mitigation Coil Invites Attention

This week, visitors from MIT and Commonwealth Fusion Systems (CFS) toured the HBT-EP tokamak research facility to learn more about the installation of the world's first Relativistic Electron Mitigation Coil (REMC) and to present lectures on the relativistic electron mitigation in the SPARC fusion energy device under construction by CFS.

In 2011, Prof. Allen Boozer first proposed the idea of installing an optimally shaped 3D conducting element inside of the vacuum vessel that is driven by the disruption voltage to provide a "fail-safe" prevention of high-energy runaway electrons. Tokamak disruptions are among the most serious events to cause potential harm to first wall of a fusion energy device. Preventing disruptions and controlling instabilities that may lead to disruptions have been a key research focus of Columbia University. Prof Boozer’s concept has also driven plans for installation of similar systems on the National DIII-D Tokamak operated by General Atomics in San Diego, and the TCV Tokamak Operated by the Ecole Polytechnique de Lausanne in Switzerland.

Dr. Jeffrey Levesque, lead scientist on the HBT-EP experiment, described details of the nearly completed REMC installation. Drs. Robert Granetz (MIT), Alex Tinguely (MIT), and John Boguski (CFS) were shown the many components installed inside the HBT-EP vacuum vessel that will be used to test the REMC concept. The flexibility of the HBT-EP device simplifies installation and enables extensive model validation. Levesque and the HBT-EP team are installing two REMC coils to investigate the role of plasma coupling. Operation of the new REMC will explore perfomance of the passive coil system, measurements of disruption forces, and the role of halo currents flowing from the plasma into the first wall.

After the day's tour of the HBT-EP facility, Drs. Tinguely and Boguski presented a seminar describing plans for disruption mitigation at the SPARC fusion energy demonstration facility and noted the importance of upcoming HBT-EP results.