Direct Fusion Drive is a a revolutionary direct-drive, fusion-powered rocket engine. Compact and clean-burning, the Direct Fusion Drive (DFD) can generate controllable power from 1-10 MW with high thrust and high specfic power. Learn more about our research from our blog posts!
On May 29, 2019, Ms. Thomas gave an invited talk to the Future In-Space Operations working group on Direct Fusion Drive (DFD) for deep space propulsion. The slides and talk audio are available from FISO’s online archive here. The group hosts weekly telecon seminars to discuss upcoming technologies and their potential impact on space operations.
Our talk introduces Direct Fusion Drive, explains how it is based on the Princeton Field Reversed Configuration (PFRC), and reviews some potential missions. There are summaries of the key physics points enabling the PFRC and the computational and modeling tools we apply. We conclude with the roadmap to spaceflight, including the supporting technologies that will be required for successful space engines, like lightweight space radiators.
We are looking for a plasma physicist to join our staff in support our new ARPA-E contract on the Princeton Field Reversed Configuration (PFRC) experiment.
Candidates should be interested in both theoretical and experimental work in plasma physics related to nuclear fusion power generation. Familiarity with low- and high-temperature plasma diagnostics is desirable. Background on any magnetic fusion device is also desirable. The position includes:
Help run experiments on the PFRC-2 (located at the Princeton Plasma Physics Laboratory) and analyze data.
Analytical and numerical work, including MHD simulations and PiC simulations.
Numerical modeling of plasmas.
Work in other areas at PSS including control, estimation, machine learning and orbit dynamics.
Programming in MATLAB, Python and C/C++.
Write proposals and come up with new topics for proposals including SBIR and STTR proposals.
Ph.D in plasma physics (may be a recent or 2019 grad)
We are pleased to announce that our Phase II STTR proposal, “Superconducting Coils for Small Nuclear Fusion Rocket Engines,” was one of 20 selected for award by NASA in this year’s round! The full list of winners is posted on NASA’s website.
Our briefing chart prepared as part of the proposal is shown below:
We will be building a testbed with a split-pair superconducting coil (two windings with a gap between them) and performing experiments to assess the impact of operating the magnets in the vicinity of the FRC plasma. Applications of the technology go beyond fusion reactors, for example science payloads and high-performance motors for hybrid electric aircraft.
Our colleague Eugene Evans of PPPL has had his paper, “Particle-in-cell studies of fast-ion slowing-down rates in cool tenuous magnetized plasma,” accepted for publication in Physics of Plasmas. The article is tentatively scheduled for the April 2018 issue. A quote from the reviewer:
The paper … is an interesting, well-written paper that uses PIC to build upon earlier direct numerical simulation methods based on molecular dynamics. The authors present a clearly written discussion of the scaling properties of slowing down theory to support their numerical studies. The authors do a very good job describing the simulation approach they take… Of particular note in the paper is the good agreement between their numerical data and the sub-thermal model even when the effective computational log(lambda) was on the order of 1… the authors did not stop with their results but instead applied their conclusions to the FRC reactor, predicting that the neutron production rate is 100 times lower than a conventional DT Tokamak.
This paper is key to the low radiation levels claimed for our PFRC design, and hence the Direct Fusion Drive. The fast ion slowing-down is what causes the tritium and other fusion ash to exit the machine. You can view a preprint on arXiv.
We will post again once the paper is published and available from Physics of Plasmas.
Back in early September, PSS and PPPL were visited by a film crew from Australia. The project? Living Universe: An Interstellar Voyage, which will include a feature documentary, a 4 episode TV miniseries, and a podcast. The documentary touches all aspects of an interstellar mission, from exoplanets to astrobiology, including transportation – which is where our fusion engine work comes in. The film is in production now and the producers expect to launch in late 2018.
The PFRC experiment at PPPL is the only hardware the documentary team could find with a path to fusion propulsion! Dr. Cohen was able to run the machine for the film crew, and both Mike and Stephanie were interviewed extensively. We discussed the rocket equation and the fundamental speed of fusion products, and how DFD moderates that speed with additional propellant to produce higher thrust. For an interstellar voyage, DFD would have to be much, much lighter than we know how to make it today – but who knows what innovations in magnets are possible in the future!
How will you be able to watch the film and TV series? The film should do the rounds of museums and IMAX theaters. The TV series will be available for streaming from Curiosity Stream, a service which specializes in science, history, tech & nature documentaries. We will post an update when we have a firm release date!
I attended the 2017 Fusion Power Associates meeting in Washington, D.C. on December 6 and 7. Fusion Power Associates is a non-profit, tax-exempt research and educational foundation, providing timely information on the status of fusion development and other applications of plasma science and fusion research.
The annual meeting brought together experts in all areas of nuclear fusion research including scientists and engineers from ITER, the Princeton Plasma Physics Laboratory, TAE Technologies, General Atomic and many others! The meeting gave a great overview of the state of nuclear fusion power generation. We learned that ITER is 50% complete and on its way to first plasma in 2025. Planning has begun on Demo, the follow-on to ITER.
There were several speakers from the University of Rochester along with colleagues from the national laboratories talking about advances in laser compression of fuel pellets. This work is for nuclear weapons research but could be applied to inertial confinement fusion.
I gave the last talk of the meeting on Princeton Satellite Systems and PPPL’s work on DFD, nuclear fusion propulsion for spacecraft.
We are pleased to report that an additional patent has been awarded for DFD! US Patent 9,822,769, “Method and Apparatus to Produce High Specific Impulse and Moderate Thrust from a Fusion-Powered Rocket Engine”, was published on Nov. 21, 2017. It’s now available from the US patent office website!
Here is a link to the patent from the Department of Energy’s Energy Innovation Portal! The inventor on the patent are Dr. Cohen, of PPPL, and three PSS engineers: Gary Pajer, Michael Paluszek, and Yosef Razin.
Fusion Rocket Engine
The first patent, “Method to Reduce Neutron Production in Small Clean Fusion Reactors,” was issued on September 9, 2017. The patent is available on Patentscope.
An interstellar asteroid, 1I/’Oumuamua, was discovered on a highly hyperbolic orbit by Robert Weryk on October 19, 2017 moving with a speed of 26.32 km/s. It appears to come from the direction of the star Vega in the constellation Lyra. It would be really great to send a mission to rendezvous and fly in formation with 1I/’Oumuamua to study the asteroid. The high velocity makes it hard to do with current technology.
Direct Fusion Drive (DFD) might provide a answer. We designed a spacecraft with a 1 MW DFD power plant and assumed a launch on March 16, 2030. The following plots show the trajectory and the force, mass and power of the spacecraft during the 23 year mission. As you can see we don’t have to use the full 1 MW for propulsion so we have plenty of power for data transmission and the science payload.