Preventing disruptions that halt fusion reactions is a top priority of the U.S. magnetic fusion program. In pursuit of that goal, Steven Sabbagh, a senior research scientist and adjunct professor at Columbia University on long-term assignment to PPPL, heads a multi-institutional project to study ways to predict and avoid disruptions on the Korean Superconducting Tokamak Advanced Research (KSTAR) facility in South Korea. The long-pulse KSTAR produces plasmas that can last from 30 seconds to a design value of more than five minutes.

“Long-pulse is where tokamaks are going,” said Sabbagh. “Future tokamaks must operate for weeks and months at a time.”

The overall effort seeks to model the step-by-step development of conditions that lead to disruptions, and to outline ways to control such conditions. The work will build on research that Sabbagh and the Columbia group have conducted on the National Spherical Torus Experiment (NSTX) at PPPL and will continue on the National Spherical Torus Experiment-Upgrade (NSTX-U).

Joining Columbia in the three-year project are PPPL and the Massachusetts Institute of Technology (MIT). Steven Scott, a principal research physicist at PPPL, leads the PPPL efforts. Earl Marmar, a senior research scientist at MIT, administrates the university’s contribution.