Compact fusion reactors

Tomas Lind´en Helsinki Institute of Physics NST2016, Helsinki, 3rd of November 2016

Fusion research is currently to a large extent focused on (ITER) and inertial confinement (NIF) research. In addition to these large international or national efforts there are private companies performing fusion research using alternative concepts, that potentially could result on a faster time scale in smaller and cheaper devices than ITER or NIF. The attempt to achieve fusion energy production through relatively small and compact devices compared to standard decreases the costs and building time of the reactors and this has allowed several private companies to enter the field, like EMC2, , , LPP Fusion, Lockheed Martin, and Tri Alpha Energy. These companies are trying to demonstrate the feasibility of their concept. If that is succesfully done, their next step is to try to demonstrate net energy production and after that to attempt to commercialize their technology. In this presentation a very brief overview of compact fusion reactor research is given. Tomas Lind´en (HIP) Compact fusion reactors 03.11.2016 1 / 24 Contents Contents

1 Fusion conditions

2 confinement

3 The reactor

4 Lockheed Martin CFR

5

6 MTF

7 Spherical tokamaks

8 Other fusion concepts

9 Summary

Tomas Lind´en (HIP) Compact fusion reactors 03.11.2016 2 / 24 Fusion conditions Fusion conditions

See Antti Hakolas presentation in this conference on mainline fusion. A useful fusion performance metric is the triple product

NτT (1) that has to execeed some threshold value for the fusion reaction in question for the to exceed and other losses and maintain a constant plasma . N is the particle density, the confinement time is τ and the temperature is T . For DT the minimum required value for a thermal plasma is 3·1021 keVs/m3. Several plasma heating methods exist. The required temperature is defined by the desired fusion reaction Achieving stable plasma confinement filling the triple product has proved hard The density and the confinement time can by varied in a large unexplored plane

Tomas Lind´en (HIP) Compact fusion reactors 03.11.2016 3 / 24 Fusion conditions Fusion conditions

The ratio of plasma to β is a figure of merit of how well the investment in the magnetic field can be utilized. Fusion power is proportional to β2. The achievable value of β is often limited by plasma instabilities.

β = pkin/pmag (2)

2 where p = N kT + N kT , p = B . N (T ), N (T ) = - kin i i e e mag 2µ0 i i e e respective particle density (temperature), k = Boltzmann constant and B = the magnetic field and µ0 = the permeability of [1]. The ITER β design value is ≈ 0.03 [2] A compact fusion reactor in this context has a significantly smaller plasma volume than a traditional tokamak because of a large value of β.

Tomas Lind´en (HIP) Compact fusion reactors 03.11.2016 4 / 24 Plasma confinement Plasma confinement

Examples of plasma confinement methods: Magnetic Confinement Fusion (MCF) Tokamak (JET, ITER, ...), (Wendelstein 7-X), ... N ≈ 1014/cm3, τ ≈ 1 s Inertial Confinement Fusion (ICF) fusion (National Ignition Facility, High Power laser Energy Research facility (HiPER), ...) N ≈ 1025/cm3, τ ≈ 1 ns (HIF) Inertial Electrostatic Confinement (IEC) (MTF) also Magneto Inertial Fusion (MIF) (General Fusion, Helion Energy, ...) [3] N ≈ 1019/cm3, τ ≈ 1 µs Magnetic confinement- and laser fusion get the majority of the funding The emphasis of laser fusion is on military applications

Tomas Lind´en (HIP) Compact fusion reactors 03.11.2016 5 / 24 Plasma confinement Plasma confinement

Plasmoids Self confined plasmas where the magnetic fields are mostly generated by currents circulating in the plasma are called or Compact Torii [4]: Field Reversed Configuration (FRC)

Plasmoid Axial- Poloidal field Toroidal field Bt symmetry Bp Bt on surface FRC yes yes no no Spheromak yes yes yes no The poloidal field is contained in planes through the symmetry axis. The toroidal field circulates the symmetry axis. FRC-plasmoids can reach β ≈ 1.

Tomas Lind´en (HIP) Compact fusion reactors 03.11.2016 6 / 24 The Polywell reactor The Polywell reactor

Figure: An EMC2 Polywell with a side Figure: Polywell field lines for β = 0. length of 21.6 cm built for β=1 studies. Simulated electron trajectories are green. confined in a magnetic cusp accelerate and confine [5, 6, 7, 8, 9] The field geometry has a stable curvature EMC2 has shown: 1995: Electrostatic fusion in a Polywell (a potential well for ions) [10] 2013: High β together with greatly increased electron confinement [2] To show the scientific feasibility of the Polywell for energy production, both of these have to be demonstrated at the same time Tomas Lind´en (HIP) Compact fusion reactors 03.11.2016 7 / 24 Lockheed Martin CFR Lockheed Martin CFR

Lockheed Martin Compact Fusion Reactor project started in 2011 T4 experiment published in February 2013 by C. Chase, aim 200 MW CFR patents published in 09/2014 [11, 12, 13, 14, 15, 16, 17, 18] T. McGuire the development at Skunk Works T4 experiment 1 m * 2 m, nominal reactor core 5.2 m * 15.2 m Axisymmetric, ideas from many concepts, mirrors at ends, DT-fuel Few open magnetic field lines, good field curvature, high β heating power 15 kW (to be increased to 100 kW) 16 17 3 Pulses ≈1 s, Te =10-25 eV, τE =4–100 µs, N=10 –10 /m [19, 20]

Tomas Lind´en (HIP) Compact fusion reactors 03.11.2016 8 / 24 Dense plasma focus Dense plasma focus

LPP Fusion (LPPF), led by E. Lerner [21] Dense Plasma Focus: J.W. Mather 1960s, N.V. Filippov 1954. An electric discharge creates the plasma, which develops through a series of instabilities to a Goal P = 5 MWe, f = 200 Hz Figure: LPPF reactor [21]. Landau quantization is expected to decrease For a DD-plasma E>150 keV has been measured [22], which is enough for p11B τ ≈ 20 ns, surpasses 8 ns goal Energy transfer to the plasmoid surpasses Figure: Electrode length ≈ 15 cm. goal with 50 % ρ needs to increase with 104 for Q = 1 Worked on reducing electron induced impurities [23] Working on reducing plasma impurities from W electrode Figure: Schematic plasma discharge. Tomas Lind´en (HIP) Compact fusion reactors 03.11.2016 9 / 24 MTF

Fusion Technologies

Plasma Energy Driver Power

1.00E+11 1.00E+15 NIF ITER $6B $20B GJ TW

1.00E+08 1.00E+12

GF MJ $150M GW

1.00E+05 1.00E+09 Cost $ of Driver $ Cost $ of Confinement

kJ MW 1.00E+02 1.00E+06 1.00E+13 1.00E+16 1.00E+19 1.00E+22 1.00E+25 Plasma Density (cm-3)

SOFE 2013 2 MTF MTF

General Fusion - acoustically heated MTF [24, 25, 26, 27, 28, 29, 30, 31] Based on LINUS concept from the 1970s Chief scientist and founder M. Laberge The planned reactor is a sphere with r = 1,5 m with a rotating molten PbLi mixture, P = 100 MWe, f = 1 Hz, Q = 6 Two plasma injectors create, accelerate and compress The spheromaks injected through the vortex in the middle collide The FRC DT-plasma is heated to fusion conditions acoustically with hundreds of computer controlled pneumatic pistons The GF concept has several advantages compared to a tokamak: No ”inner wall” problem, no needed PbLi is a coolant and multiplicator for T-generation Can be retrofitted to turbines of existing power plants Potential problems Compression and stability of the injected spheromaks Richtmyer-Meshkov instability Pb,Li-impurities can cool the plasma

Tomas Lind´en (HIP) Compact fusion reactors 03.11.2016 11 / 24 MTF MTF

Figure: General Fusions 14 piston test reactor ”Mini-Sphere”, with a diameter of one meter, is used for validating compression simulations.

Tomas Lind´en (HIP) Compact fusion reactors 03.11.2016 12 / 24 MTF MTF

The General Fusion development plan: Phase I - Proof of principle 2002 - 2008, < 1 M$ Research and development Phase II - Show net ≈ 50 M$ System development Current status [32] Physics validation Full scale prototype ≈ 500 M$ Phase III - Commercialization Alpha and power plants ≈ 2 G$ Then power production

Tomas Lind´en (HIP) Compact fusion reactors 03.11.2016 13 / 24 MTF MTF

Figure: Helion Energy, MSNW LLC Grande experiment [33, 34]. Two colliding FRCs merge to a stationary FRC The FRC is compressed magnetically in the burn chamber Ti ≈ 2,3 keV obtained for D-ions A plasmoid speed of 300 km/s has been achieved Plans to use D+D (3He) fuel Targets 50 MWe prototype in 2019 and commercialization in 2022 ARPA-E: VENTI 12 T & FEP 20 T compression, FEP-G 40 T reactor MSNW develops a fusion driven rocket (FDR) with NIAC funding compresses the plasma, absorbs and generates T

Tomas Lind´en (HIP) Compact fusion reactors 03.11.2016 14 / 24 MTF MTF

Figure: Tri Alpha Energy (TAE) experiment C-2U [35, 36, 37, 38, 39]. A FRC is produced by two colliding plasmoids The plasmoid injection speed is 250 km/s The goal is to stabilize the FRC-state with neutral beam injection and with external electric and magnetic fields The C-2 FRC lifetime was 5 ms, Ti ≈ 1 keV With C-2U a stable lifetime of 5 ms was reached C2-W to be completed in mid 2017 will aim for increased temperature TAE plans to use D3He or p11B

Tomas Lind´en (HIP) Compact fusion reactors 03.11.2016 15 / 24 Spherical tokamaks Spherical tokamaks

Mega Ampere Upgrade (MAST-U) National Spherical Torus eXperiment Upgrade (NSTX-U) Affordable, robust, compact (ARC), high field compact tokamak Tokamak Energy Ltd, high field spherical tokamak development Spinoff company from Culhamn Center fo Fusion Energy Develops superconducting based on High Temperature Superconductors (HTS) [40] ST40 3 T copper spherical tokamak [41] Demonstrate HTS mechanics in a spherical tokamak Study HH-plasma, maximize the triple product, could use DT Expected first plasma in early 2017 ST60 building planned for in 2019 Cost 120 M$, building time a few years, HH-, DD- and DT- plasmas Demonstrate energy gain, 50 MW of fusion power ST140 is the following step, 185 MW fusion power, V ≈ 40 m3 TE plans to provide power to the grid in 2030 Challenges: HTS cable construction, quality, strength and radiation protection

Tomas Lind´en (HIP) Compact fusion reactors 03.11.2016 16 / 24 Other fusion concepts Other fusion concepts

Dynomak (Univ. Washington), spheromak fusion reactor Fusion Power Corporation, heavy ion fusion Farnsworth-Hirsch [42, 43, 44, 45, 46] - likely the simplest fusion reactor, cannot probably be scaled up for energy production Can be used in research and eduction Funding for constructing a fusor has been obtained the Physics Department of the University of Helsinki and Helsinki Institute of Physics Phoenix Nuclear Labs, accelerator based 3·1011 n/s from DD-fusion [47] ...

Tomas Lind´en (HIP) Compact fusion reactors 03.11.2016 17 / 24 Summary Summary

Company Year Funding Size Type Method Reaction P target $ m MW EMC2; USA 1985 42 M 4 c IEC D+T 255 General Fusion, 2002 97 M 3 p MTF D+T(Li) 100 e LM Skunk Works, USA 2011 4 M 13 MCF D+T 200 Tokamak Energy, UK 2009 15 M c MCF D+T 100–200 Helion Energy, USA 2009 21,1 M 16 p MTF D+D(3He) 50 e Sorlox, USA 2010 1,15M < 1 p MTF D+D 0,002-1 CSI, USA 2010 120 k 7–12 c IEC p + 11B 225 e LPPF, USA 1974 4,5 M 0,15 p DPF p + 11B 5 e Tri Alpha Energy, USA 1998 500 M 20 c MTF p + 11B 100 p = pulsed, c = continuous, e = electric

Tomas Lind´en (HIP) Compact fusion reactors 03.11.2016 18 / 24 Summary Summary All possibilities of achieving fusion should be researched thoroughly by increasing funding, becuse the potential benefits are enormous Inadequate funding has affected the rate of developement Fusion break even is a very hard problem The development of plasma physics, instrumenting, software and computers has enabled some ten (privately funded) companies to do fusion research Compact fusion reactors have several advantages in terms of development time, cost, placement, applications (mobile, space, medical, material physics) Fusion reactions have been commercialized as neutron generators Small fusion reactors can be developed for medical isotope generation Pulsed fusion reactors could be simpler than continuous reactors MTF/MIF could provide a promising path to practical fusion CSI, LPPF and Tri Alpha Energy try to develop aneutronic p11B fusion GF, HE, LM, LPPF & TE aim for Q ≥ 1 within the next few years If Q  1 is reached, then commercialization is the next goal

Tomas Lind´en (HIP) Compact fusion reactors 03.11.2016 19 / 24 Additional material Additional material

A longer version of this talk: T. Lind´en, Compact fusion reactors, CERN Colloquium 26th of March 2015, https://indico.cern.ch/event/382453/ Articles on the same topic: Wayt W. Gibbs, The fusion underground, Scientific American, November 2016 Lev Grossman, Inside the Quest for Fusion, Clean Energy’s Holy Grail, Time magazine, November 02, 2015 T. Lind´en, Kompakta fusionsreaktorer, Arkhimedes 5-6, 2014, p. 16-23 D. Clery, Fusion’s restless pioneers, Science 345 6195, 25.7.2014 p. 370-375 M. M. Waldrop, The Fusion Upstarts, Nature 511, 24.7.2014 p. 398-400

Tomas Lind´en (HIP) Compact fusion reactors 03.11.2016 20 / 24 Additional material

[1] A. A. Harms, K. F. Schoepf, G. H. Miley, D. R. Kingdon, Principles of Fusion Energy: An Introduction to Fusion Energy for Students of Science and Engineering [2] J. Park et al., High Energy Electron Confinement in a Magnetic Cusp Configuration, Phys. Rev. X 5, 021024

[3] I. R. Lindemuth, R. E. Siemon, The fundamental parameter space of controlled , Am. J. Phys. 77, pp. 407-416, May 2009 [4] P. M. Bellan, Spheromaks : a practical application of magnetohydrodynamic dynamos and plasma self-organization, London : Imperial College Press, 2000 [5] J. Park, N. Krall & P. Sieck, METHOD AND APPARATUS OF CONFINING HIGH ENERGY CHARGED PARTICLES IN MAGNETIC CUSP CONFIGURATION, WIPO Patent Application WO/2015/191128

[6] Robert W. Bussard, March 1991, Fusion Technology, Volume 19, Some Physics Considerations of Magnetic Inertial Electrostatic Confinement: A New Concept for Spherical Converging Flow Fusion [7] Nicholas Krall, Fusion Technology, Volume 22, August 1992, The Polywell: A Spherically Convergent Ion Focus Concept

[8] Robert W. Bussard, November 9, 2006, Should Go Nuclear?

[9] J. Park, POLYWELL - Electric Fusion in a Magnetic Cusp, talk at Microsoft January 22, 2015

[10] Robert W. Bussard, The Advent of Clean : Superperformance for Space Power and Propulsion, Proc. 57th International Astronautical Congress, Valencia, Spain October 2-6 2006 [11] T. McGuire, ACTIVE COOLING OF STRUCTURES IMMERSED IN PLASMA, Patent publication WO/2014/204553A3

[12] T. McGuire, SYSTEM FOR SUPPORTING STRUCTURES IMMERSED IN PLASMA, Patent publication WO/2014/204554A3

[13] T. McGuire, PLASMA CONFINEMENT FOR COMPACT FUSION REACTOR, Patent publication WO/2014/204555A8

Tomas Lind´en (HIP) Compact fusion reactors 03.11.2016 21 / 24 Additional material

[14] T. McGuire, ENCAPSULATING MAGNETIC FIELDS FOR PLASMA CONFINEMENT, Patent publication WO/2014/204556A3

[15] T. McGuire, HEATING PLASMA FOR FUSION POWER USING NEUTRAL BEAM INJECTION, Patent publication WO/2014/204557A2

[16] T. McGuire, HEATING PLASMA FOR FUSION POWER USING MAGNETIC FIELD OSCILLATION, Patent publication WO/2014/204558A2

[17] T. McGuire, HEATING PLASMA FOR FUSION POWER USING ELECTROMAGNETIC WAVES, Patent publication WO/2014/204559A2

[18] T. McGuire, MAGNETIC FIELD PLASMA CONFINEMENT FOR COMPACT FUSION POWER REACTOR, Patent publication WO/2014/165641A1

[19] T. McGurie, The Lockheed Martin Compact Fusion Reactor

[20] T. McGurie, Overview of the Lockheed Martin Compact Fusion Reactor (CFR) Program

[21] Eric J. Lerner, S. Krupakar Murali, A. Haboub, Theory and Experimental Program for p + 11B Fusion with the Dense Plasma Focus J Fusion Energy (2011) 30:367-376

[22] Eric J. Lerner et al., Fusion reactions from >150 keV ions in a dense plasma focus plasmoid, Phys. Plasmas 19, 033704 (2012)

[23] Eric J. Lerner and Hamid R. Yousefi, Runaway electrons as a source of impurity and reduced fusion yield in the dense plasma focus, Phys. Plasmas 21, 102706 (2014)

[24] M. Laberge, An Acoustically Driven Magnetized Target Fusion Reactor, J Fusion Energ (2008) 27:65-68

[25] S. Howard, M. Laberge, L. McIlwraith, D. Richardson, J. Gregson, Development of Merged Compact Toroids for Use as a Magnetized Target Fusion Plasma, J Fusion Energ (2009) 28:156-161

[26] M. Laberge, Experimental Results for an Acoustic Driver for MTF J Fusion Energ (2009) 28:179-182

Tomas Lind´en (HIP) Compact fusion reactors 03.11.2016 22 / 24 Additional material

[27] P. J.F. Carle, S. Howard, J. Morelli, High-bandwidth polarimeter for a high density, accelerated spheromak, Rev Sci Instrum 84, 083509 (2013)

[28] V. Suponitsky, A. Froese, S. Barsky, Richtmyer-Meshkov instability of a liquid-gas interface driven by a cylindrical imploding pressure wave, Computers & Fluids 89 (2014) 1-19

[29] M. Laberge, S. Howard, D. Richardson, A. Froese, V. Suponitsky, M. Reynolds, D. Plant, Acoustically driven Magnetized Target Fusion, Proc. Fusion Engineering (SOFE), 2013 IEEE 25th Symposium on Fusion Engineering, June 10-14, 2013, San Francisco, California, USA, http://dx.doi.org/10.1109/SOFE.2013.6635495

[30] M. Lindstrom, S. Barsky, B. Wetton, Investigation into Fusion Feasibility of a Magnetized Target Fusion Reactor: A Preliminary Numerical Framework, J Fusion Energ (2015) 34:76-83

[31] M. Lindstrom, Assessment of the Effects of Azimuthal Mode Number Perturbations upon the Implosion Processes of Fluids in Cylinders, arXiv:1602.01865 [physics.flu-dyn]

[32] M. Laberge, Acoustically driven Magnetized Target Fusion at General Fusion

[33] J. Slough, G. Votroubek and C. Pihl, Creation of a high-temperature plasma through merging and compression of supersonic field reversed configuration plasmoids, Nucl. Fusion 51 (2011) 053008

[34] A. Pencotti, Electromagnetically Driven Fusion Propulsion, NASA’s Innovative Advanced Concepts symposium 4-6.2.2014

[35] M. Tuszewski et al., Field Reversed Configuration Confinement Enhancement through Edge Biasing and Neutral Beam Injection, Phys Rev Lett 108, 255008 (2012)

[36] M. W. Binderbauer et al., Dynamic Formation of a Hot Field Reversed Configuration with Improved Confinement by Supersonic Merging of Two Colliding High-Beta Compact Toroids, Phys Rev Lett 105, 045003 (2010)

[37] H. Gota al., IMPROVED CONFINEMENT OF C-2 FIELD-REVERSED CONFIGURATION PLASMAS, Fus. Sci. and Tech. V. 00, July 2015 [38] H.Y. Guo et al., Achieving a long-lived high-beta plasma state by energetic beam injection, Nature Comm. 6, 6897

Tomas Lind´en (HIP) Compact fusion reactors 03.11.2016 23 / 24 Additional material

[39] M. W. Binderbauer et al., A high performance field-reversed configuration, Phys. Plasmas 22, 056110 (2015)

[40] A. Sykes et al., Compact Fusion Energy based on the Spherical Tokamak

[41] M. Gryaznevich, Overview and status of construction of ST40

[42] Tom Ligon, The World’s Simplest Fusion Reactor, And How to Make It

[43] Philo T. Farnsworth, Electric Discharge Device for Producing Interactions Between Nuclei, U.S. Patent Number 3,258,402 June 28, 1966 [44] Robert L. Hirsch, Inertial-Electrostatic Confinement of Ionized Fusion Gases, J Appl Phys 38 (1967) 4522-4534

[45] Robert L. Hirsch; Erratum: Inertial-Electrostatic Confinement of Ionized Fusion Gases, J Appl Phys 39, (1968) 4047

[46] Robert L. Hirsch; Experimental studies of a deep, negative, electrostatic potential well in spherical geometry, 1968, Physics Fluids, 11, 2486-90 [47] G.L.Kulcinski, Recent Progress at Phoenix Nuclear Labs and SHINE Medical Technologies, 15th Workshop on Inertial Electrostatic Confinement Fusion, October 6-9 Uji, Kyoto,

Tomas Lind´en (HIP) Compact fusion reactors 03.11.2016 24 / 24