The National Spherical Torus Experiment-Upgrade (NSTX‑U)
The National Spherical Torus Experiment-Upgrade (NSTX-U) is the flagship fusion facility at PPPL. The spherical device is shaped more like a cored apple than the doughnut-like shape of conventional tokamaks and can produce high-pressure plasmas — essential ingredients for fusion reactions — with relatively low and cost-effective magnetic fields. This capability makes the compact spherical design of the NSTX-U a candidate to serve as the model for a fusion pilot plant followed by a commercial fusion reactor.
Image: Overview of the National Spherical Torus Experiment-Upgrade (NSTX-U)

NSTX-U has three main objectives:
- To explore the capability of the spherical facility to produce stable, high-performance plasmas with low-cost magnetic fields.
- To develop the understanding and tools required to start-up and sustain such plasmas non-inductively, meaning without what is known as a “solenoid” magnet to start the process.
- To develop techniques to handle and control the waste heat from fusion reactions.

The NSTX-U in operation
Temperature of the doughnut-shaped plasma encircling the central column can exceed 10 million degrees Celsius.



Fusion plasma during an experiment in the NSTX-U


NSTX-U Research
- Head: Stan Kaye
- Deputy Head: Rajesh Maingi
- Experimental Research Operations: Stefan Gerhardt
- Diagnostic Operations: Brent Stratton
- Physics Analysis: Stan Kaye
- Boundary Physics: Rajesh Maingi
- Radio Frequency Science: Masa Ono
Image: NSTX-U render, Walter Guttenfelder, Filippo Scotti

NSTX-U COLLABORATIONS

United States
College of William and Mary
Columbia University
CompX
Florida International University
General Atomics
Idaho National Laboratory
Johns Hopkins University
Lawrence Livermore National Laboratory
Lehigh University
Lodestar Research Corporation
Los Alamos National Laboratory
Massachusetts Institute of Technology
Nova Photonics Inc.
Oak Ridge National Laboratory
Old Dominion University
Princeton Plasma Physics Laboratory
Princeton University
Purdue University
Sandia National Laboratory
University of California-Davis
University of California-Irvine
University of California-Los Angeles
University of California-San Diego
University of California, Space Sciences Laboratory
University of Colorado
University of Illinois
University of Maryland
University of Rochester
University of Tennessee
University of Texas
University of Washington
University of Wisconsin
International
ASIPP
Culham Centre for Fusion Energy
FOM Institute DIFFER
Hiroshima University
Institute for Nuclear Research-National Academy of Science
Institute of Plasma Physics-Czech Republic
Ioffe Physical-Technical Institute
Japan Atomic Energy Agency
International Thermonuclear Experimental Reactor
KAIST-Korea Advanced Institute of Science and Technology
Kyoto University Kyushu University
NFRI-National Fusion Research Institute
Niigata University
Seoul National University
Tech-X Corporation
Tokamak Energy
TRINITI-Troitskii Institute of Innovative and Thermonuclear Research
Ulsan Science Institute of Science and Technology
University of Costa Rica
University of Hyogo
University of Tokyo
University of York