Three new public-private INFUSE projects to speed development of fusion energy selected for PPPL

Written by
John Greenwald
Jan. 25, 2021

State-of-the-art fusion research at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) has brought the lab three new public-private contracts to facilitate harnessing on Earth the fusion that powers that sun and stars. The awards under the DOE’s recent Innovation Network for Fusion Energy (INFUSE) program represent three of the 10 second-round INFUSE partnerships designed to speed the development of fusion as a virtually limitless source of energy for generating electricity.

“These contracts provide PPPL expertise to private companies that are working on fusion energy,” said PPPL physicist Ahmed Diallo, the Deputy Director of INFUSE who works with Director Dennis Youchison of Oak Ridge National Laboratory (ORNL) to organize reviews of industry proposals. “National laboratories like ours and ORNL have know-how that companies are eager to tap into.”

The projects are subject to successful negotiation of Cooperative Research and Development Agreements, with funding ranging from $50,000 to $500,000 per contract. Private companies provide at least 20% of the overall cost with DOE supplying the remainder. 

Fusion combines light elements in the form of plasma — the state of matter composed of free electrons and atomic nuclei that makes up 99 percent of the visible universe — to produce vast energy. Scientists around the world are seeking to duplicate the process as a virtually unlimited source of energy for generating electricity.

The following companies will collaborate with PPPL under second-round contracts.

• TAE Technologies. This Foothill Ranch, California, company is developing a fusion reactor based on the field-reversed configuration (FRC) concept that produces a smoke ring-like high-pressure plasma that holds itself together with its own magnetic field. Such vertical reactors can be smaller than the doughnut-shaped tokamak reactors that scientists use around the world and have a simple linear geometry.

TAE previously worked on an INFUSE project with PPPL and now is turning to the laboratory to help produce an FRC plasma into which high energy ion beams will be injected. The project calls for PPPL to assist TAE’s construction of two plasma guns that will be installed on the Magnetic Reconnection Experiment (MRX) at PPPL to produce an FRC target plasma. "PPPL will then experimentally test the stability of the plasma and perform numerical simulations to check the experiments,” said Masaaki Yamada, principal investigator of the MRX, who will work with PPPL physicists Hantao Ji and Elena Belova on the collaborative project. 

• Princeton Fusion Systems. This small Plainsboro, New Jersey, company has long partnered with PPPL physicist Sam Cohen, who is developing the Princeton Field Reversed Configuration (PFRC) reactor as a small, clean source of energy for Earth-bound and space uses. The company aims to develop the reactor into a portable supplier of power for diverse applications ranging from remote industrial facilities to off-world bases on the moon or Mars.

The INFUSE project calls for installing an advanced diagnostic, constructed and operated by ORNL researchers, on the current phase of the PFRC to measure key features of the magnetic field. Such measurements are intended to indicate whether the method planned for forming the plasma will produce sufficiently hot and dense plasma to create fusion reactions. Expected results include what the project says will be accelerated development of future PFRC-relevant devices and feedback to guide the optimization of device configurations.

“The advanced diagnostic, constructed and operated by ORNL researchers,  will provide a groundbreaking and essential capability, the first non-invasive measurement of the magnetic field inside the plasma of FRC devices,” Cohen said. 

Cohen and members of Princeton Satellite Systems, a sister company, won the New Jersey Research & Development Council’s 2020 Thomas Edison Patent Award for Emerging Technology for their PFRC-based invention of a compact rocket engine thruster propelled by a small fusion reactor for rapid space travel.

• Tokamak Energy. This spinoff from the Culham Center for Fusion Energy in the United Kingdom is developing a spherical, cored apple-shaped tokamak called ST40 that will confine the plasma with high temperature superconducting (HTS) magnets that produce high magnetic fields. The fusion facility at PPPL, the National Spherical tokamak Experiment-Upgrade (NSTX-U), is also a spherical tokamak.

The company previously collaborated on an INFUSE project with PPPL and now seeks to calculate the width of the so-called scrape-off layer — the heat that separates from the edge of the plasma and flows into the divertor region that vents exhaust energy from the system. If the layer is too thin and concentrated it could damage the region and halt fusion reactions.

The new INFUSE project turns to PPPL and its state-of-the-art XGC1 code to calculate the width and deposition of heat in an ST40 spherical tokamak with a high magnetic field. The high-fidelity plasma turbulence code can model the complicated physics at the tokamak boundary in realistic geometry. The project aims to provide insight into the design of the divertor in the company’s next-step device and indicate areas that can be experimentally tested on the company’s present facility over the next two-to- three years.

Collaborating on this project will be C.S. Chang, who manages multiple extreme-scale computing projects and has overseen development of the XGC code. Working with him will be PPPL physicists Seung-Hoe Ku, Robert Hager, Randy Michael Churchill, and George Wilkie.

The three new projects bring to nine the number of PPPL public-private awards since the INFUSE program began in 2019. Previous INFUSE collaborations have worked with private fusion developers TAE Technologies, Tokamak Energy, Commonwealth Fusion Systems, General Fusion, and Helicity Space. PPPL collaborators have included physicists Elena Belova, Nicola Bertelli, Mario Podesta, Gerrit Kramer, Walter Guttenfelder, Zhirui Wang, engineer Amuliu Bogdan Proca who has replaced Clement Bovet, and Dylan Brennan, who is affiliated with Princeton University.  

PPPL, on Princeton University's Forrestal Campus in Plainsboro, N.J., is devoted to creating new knowledge about the physics of plasmas — ultra-hot, charged gases — and to developing practical solutions for the creation of fusion energy. The Laboratory is managed by the University for the U.S. Department of Energy’s Office of Science, which is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit

PPPL is mastering the art of using plasma — the fourth state of matter — to solve some of the world's toughest science and technology challenges. Nestled on Princeton University’s Forrestal Campus in Plainsboro, New Jersey, our research ignites innovation in a range of applications including fusion energy, nanoscale fabrication, quantum materials and devices, and sustainability science. The University manages the Laboratory for the U.S. Department of Energy’s Office of Science, which is the nation’s single largest supporter of basic research in the physical sciences. Feel the heat at and