News: Disruption Mitigation System

R&D engineer and pellet injection scientist Trey Gebhart of the Blanket and Fuel Cycle group in ORNL’s Fusion Energy Division with a pellet injection system testbed used for fusion R&D. The group leads the world in pellet injection R&D.

Perfecting the Pellet


A team of experts at Oak Ridge National Laboratory is taking aim at one of the biggest challenges facing the international ITER fusion facility: turning cold gas into wine-cork-sized, solid pellets to help keep ITER’s plasma in check.

The KSTAR superconducting tokamak in Daejeon, South Korea before installation of the two shattered pellet injectors.

KSTAR joins an exclusive club: Tandem shattered pellet injectors now in testing for disruption mitigation


–Adriana Ghiozzi for US ITER First-of-a-kind experiments have begun at the KSTAR tokamak in Daejeon, South Korea, where two new shattered pellet injectors were installed in October and December. The tandem use of shattered pellet injectors installed at opposite sides of the machine is a first for the technology, which was developed and fabricated at […]

A three-barrel pellet injector developed at Oak Ridge National Laboratory for the ITER disruption mitigation system.

Mitigating plasma disruptions in ITER: Using large cryogenic pellets, US ITER advances new fusion technology


The international ITER fusion project is building “a sun on earth” that will produce a self-heated, burning plasma—a key step toward industrial-scale fusion energy production. Controlling that plasma can be tricky, though, because disruptions may occur that cool and collapse the plasma. Sudden losses of plasma energy and current have the potential to erode plasma-facing […]

Thermal quench (TQ) and current quench (CQ) studies are part of the research underway on disruption mitigation and runaway electron suppression.

Disruption mitigation researchers investigate design options


ITER, the world’s first reactor-scale fusion machine, will have a plasma volume more than 10 times that of the next largest tokamak, JET. Plasma disruptions that can occur in a tokamak when the plasma becomes unstable can potentially damage plasma-facing surfaces of the machine. To lessen the impact of high energy plasma disruptions, US ITER […]

A neutronics model of ITER is behind (left to right) Ed Marriott, Tim Bohm, Paul Wilson, Mohamed Sawan and Ahmad Ibrahim, US ITER researchers at the University of Wisconsin.

“Neutronics” at Wisconsin, ORNL advances ITER shielding and international collaboration


Computer codes calculate nuclear heating, neutron radiation damage and activation of fusion reactor materials. ―Lynne Degitz US ITER researchers at the University of Wisconsin and Oak Ridge National Laboratory are developing advanced processes to assess ITER’s unique tokamak components and materials in the presence of the tremendous amount of neutron flux and energy released by […]

Steve Combs holds target materials for evaluating disruption mitigation pellet size.

ORNL’s Fusion Pellet Fueling Lab Innovations Support US ITER Systems


―Agatha Bardoel  Oak Ridge National Laboratory’s Fusion Pellet Fueling Lab has been at the center of design and testing of plasma fueling systems for tokamak research applications for decades. Since the mid-1970s, lab researchers have been designing, testing, and contributing hardware for fusion magnetic confinement experiments here in the United States and around the world. […]