See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/284228265 Magneto-Inertial Fusion Article in Journal of Fusion Energy · February 2016 DOI: 10.1007/s10894-015-0038-x CITATIONS READS 46 587 17 authors, including: Glen A. Wurden Scott C. Hsu Los Alamos National Laboratory Los Alamos National Laboratory 400 PUBLICATIONS 4,528 CITATIONS 259 PUBLICATIONS 2,481 CITATIONS SEE PROFILE SEE PROFILE Chris Grabowski Matt Domonkos Air Force Research Laboratory Air Force Research Laboratory 118 PUBLICATIONS 647 CITATIONS 105 PUBLICATIONS 823 CITATIONS SEE PROFILE SEE PROFILE Some of the authors of this publication are also working on these related projects: Plasma Diagnostics View project Magnetic reconnection View project All content following this page was uploaded by Glen A. Wurden on 22 November 2015. The user has requested enhancement of the downloaded file. J Fusion Energ DOI 10.1007/s10894-015-0038-x ORIGINAL RESEARCH Magneto-Inertial Fusion 1 1 1 2 2 G. A. Wurden • S. C. Hsu • T. P. Intrator • T. C. Grabowski • J. H. Degnan • 2 3 4 4 5 M. Domonkos • P. J. Turchi • E. M. Campbell • D. B. Sinars • M. C. Herrmann • 6 7 7 7 8 R. Betti • B. S. Bauer • I. R. Lindemuth • R. E. Siemon • R. L. Miller • 9 9 M. Laberge • M. Delage Ó The Author(s) 2015. This article is published with open access at Springerlink.com Abstract In this community white paper, we describe an fusion (MCF). From an MCF perspective, the higher density, approach to achieving fusion which employs a hybrid of shorter confinement times, and compressional heating as the elements from the traditional magnetic and inertial fusion dominant heating mechanism reduce the impact of instabil- concepts, called magneto-inertial fusion (MIF). The status ities. From an ICF perspective, the primary benefits are of MIF research in North America at multiple institutions is potentially orders of magnitude reduction in the difficult to summarized including recent progress, research opportu- achieve qr parameter (areal density), and potentially sig- nities, and future plans. nificant reduction in velocity requirements and hydrody- namic instabilities for compression drivers. In fact, ignition Keywords Magneto-inertial fusion Á Magnetized target becomes theoretically possible from qr B 0.01 g/cm2 up to fusion Á Liner Á Plasma jets Á Fusion energy Á MagLIF conventional ICF values of qr * 1.0 g/cm2, and as in MCF, Br rather than qr becomes the key figure-of-merit for ignition because of the enhanced alpha deposition [4]. Within the Description lower-qr parameter space, MIF exploits lower required implosion velocities (2–100 km/s, compared to the ICF Magneto-inertial fusion (MIF) (aka magnetized target minimum of 350–400 km/s) allowing the use of much more fusion) [1–3] is an approach to fusion that combines the efficient (g C 0.3) pulsed power drivers, while at the highest compressional heating of inertial confinement fusion (ICF) (i.e., ICF) end of the qr range, both higher gain G at a given with the magnetically reduced thermal transport and mag- implosion velocity as well as lower implosion velocity and netically enhanced alpha heating of magnetic confinement reduced hydrodynamic instabilities are theoretically possi- ble. To avoid confusion, it must be emphasized that the well- known conventional ICF burn fraction formula does not & G. A. Wurden apply for the lower-qr ‘‘liner-driven’’ MIF schemes, since it [email protected] is the much larger mass and qr of the liner (and not that of the burning fuel) that determines the ‘‘dwell time’’and fuel burn- 1 Los Alamos National Laboratory, Los Alamos, NM, USA up fraction. In all cases, MIF approaches seek to satisfy/ 2 Air Force Research Laboratory, Albuquerque, NM, USA exceed the inertial fusion energy (IFE) figure-of-merit 3 Santa Fe, NM, USA gG * 7–10 required in an economical plant with reasonable 4 Sandia National Laboratory, Albuquerque, NM, USA recirculating power fraction. A great advantage of MIF is 5 indeed its extremely wide parameter space which allows it Lawrence Livermore National Laboratory, Livermore, CA, USA greater versatility in overcoming difficulties in implemen- tation or technology, as evidenced by the four diverse 6 University of Rochester, Rochester, NY, USA 7 approaches and associated implosion velocities shown in University of Nevada Reno, Reno, NV, USA Fig. 1. 8 Decysive Systems, Santa Fe, NM, USA MIF approaches occupy an attractive region in ther- 9 General Fusion, Vancouver, Canada monuclear q-T parameter space, as shown in a paper by 123 J Fusion Energ Fig. 1 Many of the MIF concepts presently being explored in the USA Lindemuth and Siemon [3] from physics first principles. solid liner compression of magnetically confined field-re- The center of the attractive region is at a density value that versed configuration (FRC) plasmas to achieve kilovolt is approximately the geometric mean of ICF and MCF. A temperatures [5–7]. The University of Rochester has key point here is that burning plasma class MIF driver introduced seed magnetic fields into the center of targets at facilities, which already exist (e.g., Z/Z-Beamlet, or per- the OMEGA laser facility, and compressed those fields by haps ATLAS), cost B$200 M compared to the multi-$B imploding a liner with the OMEGA laser. They have ITER and NIF. These existing facilities can address much obtained record values of magnetic field and demonstrated of the physics critical to MIF concepts that are required for increases in neutron yields [8–10]. Sandia is developing large fusion yields and system gain. For this reason alone, magnetized liner inertial fusion (MagLIF), in which a MIF warrants serious attention. Furthermore, the density magnetically driven beryllium liner, imploded by the regime of MIF is in a relatively unexplored area of mag- Z-machine, adiabatically compresses a laser-preheated netized plasma physics and plasma/material interactions, magnetized DT target plasma [11–14]. In the very first thereby allowing a multitude of opportunities in plasma series of integrated MagLIF shots last year, [1011–1012 science frontiers. DD neutrons were observed, indicating significant improvement in target performance due to the presence of preheated and magnetized fuel in the target [15]. The Status experiments also showed a significant DT/DD ratio -2 (*10 ) from a pure D2 fuel indicating magnetization of The USA is a world leader in MIF research. In the last the DD fusion produced tritons [16] with an estimated B*R 10 years, there have been substantial advances and grow- product of 0.4 MG-cm (which was also separately inferred ing interest in MIF research and concepts. A team led by from DT neutron time of flight measurements). LANL also Los Alamos National Laboratory (LANL) and the Air leads a team that is exploring a standoff concept of using a Force Research Laboratory (AFRL) has been investigating spherically convergent array of gun-driven plasma jets to 123 J Fusion Energ achieve assembly and implosion of a plasma liner (PLX) Related R&D Activities without the need to destroy material liners or transmission lines on each shot [17–20]. A private company, general MIF reactor systems tend toward larger yields and lower fusion (GF) in Canada, with many Americans working for repetition rates than conventional unmagnetized ICF, and it, is developing a merging compact toroid plasma source most likely as a result will need to (and are able to) use and envisions repetitively fired acoustic drivers that would liquid-walled chamber systems, which are also relevant for drive a liquid liner compression of a magnetized target other ICF targets and drivers especially heavy-ion beam [21–23]. driven fusion. Liquid ‘‘fusion facing’’ walls have the Much of the current MIF work can be traced back, at potential to significantly reduce the ‘‘first wall’’ material least in part, to work on imploding liners for controlled challenges common for most mainline approaches to fusion fusion at the Kurchatov Institute of Atomic Energy, under energy. Present MIF work falls under the category of E. P. Velikhov, circa 1970 [24]. This inspired the Linus Magnetized High Energy Density Laboratory Plasmas, and project at the Naval Research Laboratory [25], and later the its science is well documented in the recent FESAC fast-liner project at Los Alamos [26]. In Russia, MIF took a HEDLP Basic Research Needs Report (2010) and the form called magnitnoye obzhatiye, or magnetic compres- National Academy of Sciences Inertial Confinement Fusion sion (MAGO), first revealed by Russian scientists when the report (2013). Cold War ended [27–29], and worked on collaboratively with experiments at LANL [30]. Presently the USA clearly Recent Progress holds world leadership in MIF research, but fledgling MIF efforts are also underway in China and France. Russia has At Rochester LLE, a fusion yield enhancement due to a also stated that it is constructing a pulsed power facility at compressed magnetic field that was externally introduced twice the current (*50 MA) and four times the delivered into the fusion fuel prior to laser-driven implosion has been energy to the load compared to Z to explore MIF concepts. unequivocally demonstrated experimentally using the These approaches span implosion time scales ranging from OMEGA laser. The results are consistent with 1-D mod- ns to hundreds of ls and all have substantially different eling estimates. In spherical implosions of solenoidal (ax- ‘‘target physics’’ issues. ial) magnetic field with open field lines, a statistically significant neutron yield increase of 30 % was obtained, and proton deflectometry measured a compressed magnetic Current Research and Development (R&D) field of 23 Megagauss in similar spherical implosions. If magnetic field with closed field lines could be introduced in R&D Goals and Challenges the same target plasma, a factor of 2 to 4 increase in neutron yields is expected.