Fusion Energy Research at the National Ignition Facility: the Pursuit of the Ultimate Clean, Inexhaustible Energy Source

Fusion Energy Research at The National Ignition Facility: The Pursuit of the Ultimate Clean, Inexhaustible Energy Source

John D. Moody, Lawrence Livermore National Laboratory Presented to: MIT – PSFC IAP 2014 January 15, 2014 This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 A few memories of MIT physics (1982 – 1988)

Fast-wave ICRF antenna

John Frank

NIF-0709-16940 Presentation to MIT 2 World energy consumption is projected to double in about 40 years Source: US Energy Information Agency

OECD = Organization for Economic Cooperation and Development

NIF-0709-16940 Presentation to MIT 3 NIF-0412-24385.pptNIF-0709-16940 Presentation to MIT Moses-IPAM_UCLA_041812 94 NIF-0412-24385.pptNIF-0709-16940 Presentation to MIT Moses-IPAM_UCLA_041812 175 Fission and Fusion both Release Binding Energy from the Atomic Nucleus

Fission neutron Fusion Deuterium Chemical 235U/239Pu D neutron neutron + + O D

= helium neutron

E = m c2

D2O ~0.1% mass ~0.4% mass converted to converted to 3 eV energy energy

NIF-0709-16940 Presentation to MIT 6 Coulomb barrier makes high temperatures necessary for DT thermonuclear fusion

Fusion Rate vs DT Temperature D α

T n D + T → α + n 3.5 MeV 14.1 MeV

11 QFusion = 3.3 ⋅10 J / g

NIF-0709-16940 Presentation to MIT 7 There are three (and maybe more…) ways to achieve fusion

~3mm

Gravitational Magnetic Inertial Confinement Confinement Confinement

“Thermo- nuclear” Muon-catalyzed fusion

NIF-0709-16940 Presentation to MIT 8 Livermore

Malibu

NIF-0709-16940 Presentation to MIT 9 Malibu in the 60s

NIF-0412-24385.pptNIF-0709-16940 Moses-IPAM_UCLA_041812Presentation to MIT 1910 Ted Maiman Demonstrated the ﬁrst laser May 16, 1960 Hughes Research Laboratories Malibu, California

NIF-0709-16940 Presentation to MIT 11 3 days later at the Lawrence Radiation Laboratory In Livermore, California…

NIF-0709-16940 Presentation to MIT 12 …John Nuckolls proposed to use lasers for fusion energy

NIF-0709-16940 Presentation to MIT 13 In 1972, the requirements for laser driven ICF were quantiﬁed in a seminal paper

• John Nuckolls, Lowell Wood, Albert Thiessen and George Zimmerman, Nature 239, 139-142 (1972) • Nuckolls, et. al., showed that ICF fusion with high gain was theoretically possible with laser energies of ~1kJ in a ns-scale pulse — Experience has shown that the actual energy required will be in excess of 1MJ • The highest output lasers of the time produced many orders of magnitude less energy than was needed • Since the 1970s, a series of successively larger lasers has been built at Livermore and elsewhere approaching the 1MJ goal

NIF-0709-16940 Presentation to MIT 14 In an ICF reaction, a Deuterium-Tritium (DT) sphere is compressed radially, as if by the Sun’s gravity

Irradiation Compression Ignition Burn Radiation heats the Fuel core is Fuel core reaches Fusion process surface, forming compressed by the ~10x the temp. and propagates a plasma (ablation) rocket-like blowoff density of the sun through fuel at the surface and ignites yielding many times the energy

NIF-0709-16940 Presentation to MIT 15 Two approaches to ICF trade off efﬁciency and drive uniformity: Direct Drive and Indirect Drive

Direct drive capsule Laser beams impinge directly on capsule

High coupling efficiency ηC ~ 80 % but requires very uniform illumination laser Indirect drive beam x-rays Lasers illuminate walls of high-Z enclosure (hohlraum) and produce x- rays that ablate surface Reduces beam uniformity requirements but also significantly reduces coupling efficiency η ~ 20 % high-Z C hohlraum

NIF-0709-16940 Presentation to MIT 16 In the early 1970s, John Emmett at Livermore recognized that ﬂashlamp pumped, solid-state lasers were capable of scaling to 1MJ

NIF-0709-16940 Presentation to MIT 17 Janus,Janus, 1973, 1973 100J IR

NIF-0709-16940 Presentation to MIT 18 Argus, 1976, 1 kJ IR

NIF-0709-16940 Presentation to MIT 19 Nova, 1985, 100 kJ IR, 30kJ UV

NIF-0709-16940 Presentation to MIT 20 NIF-0412-24385.pptNIF-0709-16940 Moses-IPAM_UCLA_041812Presentation to MIT 2134 NIF, 2009,NIF, 20091.8 MJ UV

NIF-0709-16940 Presentation to MIT 22 NIF, 2009 4MJ IR

2012-040806s1.pptNIF-0709-16940 Moses - AllPresentation Hands, September to MIT 19, 2012 4023 Target Chamber June 1999

NIF-0412-24385.pptNIF-0709-16940 Moses-IPAM_UCLA_041812Presentation to MIT 4124 Inside the target chamber

NIF-0412-24385.pptNIF-0709-16940 Moses-IPAM_UCLA_041812Presentation to MIT 4425 2012-040806s1.pptNIF-0709-16940 MosesPresentation - All Hands, September to MIT 19, 2012 2645 In a typical NIF experiment, the DT fuel capsule will be inside a small container, or hohlraum

~5mm ~1cm

NIF-0709-16940 Presentation to MIT 27 Ignition requires high convergence spherical compression DT shot N120716 Bang time 215 µm

2 mm

NIF-0709-16940 Presentation to MIT 28 Beth holding the target

NIF-0412-24385.pptNIF-0709-16940 Moses-IPAM_UCLA_041812Presentation to MIT 2529 Fuel capsule

NIF-0412-24385.pptNIF-0709-16940 Moses-IPAM_UCLA_041812Presentation to MIT 2630 On September 29, 2010 NIC conducted the first cryo-layered DT experiment on NIF

NIF-0709-16940 Presentation to MIT 31 DT ice layer is carefully grown over ~ 24 hours

NIF-0709-16940 Presentation to MIT 32 In the target chamber

NIF-0412-24385.pptNIF-0709-16940 Moses-IPAM_UCLA_041812Presentation to MIT 4733 NIF irradiates a fusion target with an array of 192 laser beams

NIF-0709-16940 Presentation to MIT 34 NIF’s laser beams irradiate the hohlraum (indirect drive) to produce x-rays that irradiate the capsule

NIF-0709-16940 Presentation to MIT 35 MIT

NIF-0709-16940 Presentation to MIT 36 The National Ignition Campaign (NIC) is a four-step experimental plan for demonstrating ICF energy gain

Demonstrate Laser Performance

Demonstrate Hohlraum Performance

Demonstrate Capsule Performance

Integrated Test

NIF-0709-16940 Presentation to MIT 37 The National Ignition Campaign (NIC) is a four-step experimental plan for demonstrating ICF energy gain

Demonstrate Laser Performance

Demonstrate Hohlraum Performance

Demonstrate Capsule Performance

Integrated Test

NIF-0709-16940 Presentation to MIT 38 1.8 MJ NIC ignition point design, energy, power, pulse shape & beam smoothing achieved simultaneously (single beam)

NIF-0709-16940 Presentation to MIT 39 The NIF laser has steadily increased the laser power and energy available for ignition experiments

Shaped pulses up to 1.9 MJ, 520 TW delivered to cryogenic implosion targets

2012 500

2011 400 2010 300 2009 200 3w Power at Target (TW) 100

0 0.0 0.5 1.0 1.5 2.0 3w Energy at Target (MJ)

NIF-0709-16940 Presentation to MIT 40 520 TW is ~ the power the sun delivers to New England + New York + New Jersey

Sun Earth 1.44 kW / m2 Sun’s power at earth’s surface

New England + New York + 514 TW New Jersey

NIF-0709-16940 Presentation to MIT 41 The National Ignition Campaign (NIC) is a four-step experimental plan for demonstrating ICF energy gain

Demonstrate Laser Performance

Demonstrate Hohlraum Performance

Demonstrate Capsule Performance

Integrated Test

NIF-0709-16940 Presentation to MIT 42 Ignition hohlraum simulation: from start to finish

NIF-0709-16940 Presentation to MIT 43 Early time x-rays, cross-beam energy transfer (CBET) and hot e- can cause symmetry swings and preheat – limiting convergence

Cross-beam energy transfer

Hot electron preheat

12 x-rays

10 8

8 x 12 4 6

x 10 2 4

8 0 Mitigations: low-power to blow- 2

6 3 -2 -2

x 0 2

4 1 -1

2 -2

0 down window; power adjustment 0 1 2 3

-2 -1 0 y

1 0 y -1

-2 2 -2

3 on inner / outer beam cones

NIF-0709-16940 Presentation to MIT 44 Late-time backscatter and hot e- can affect symmetry, convergence, and capsule speed

Cross-beam energy transfer

SBS- outers

SRS and SBS- inners

X-rays

Hot electron preheat How can we make the inner beams propagate better?

NIF-0709-16940 Presentation to MIT 45 Efficiency, symmetry, and hot-electron preheat are three areas of hohlraum performance we are working on

Efficiency

Backscatter Hohlraum ~ 15% x-rays

Laser

Capsule R(t)

15-25% Implosion degraded simulations flux after match data using backscatter degraded drive

Full flux simulation How do we recover 30-40% missing laser power?

NIF-0709-16940 Presentation to MIT 46 Efficiency, symmetry, and hot-electron preheat are three areas of hohlraum performance we are working on

Efficiency Symmetry, and hot-electrons

Backscatter Hohlraum Oblate Prolate ~ 15% x-rays Stagnation Laser How can we control the time- dependent symmetry?

Capsule R(t)

15-25% Implosion degraded simulations flux after match data using backscatter degraded drive

Full flux simulation How do we recover 30-40% missing laser power?

NIF-0709-16940 Presentation to MIT 47 Efficiency, symmetry, and hot-electron preheat are three areas of hohlraum performance we are working on

Efficiency Symmetry, and hot-electrons

Backscatter Hohlraum Oblate Prolate ~ 15% x-rays Stagnation Laser How can we control the time- dependent symmetry?

≥ 1.8 keV Capsule R(t) X-rays

15-25% Implosion degraded simulations flux after match data using backscatter degraded drive

Full flux simulation Hot electron How do we preheat recover 30-40% missing laser power? How can we observe pre-heat – and mitigate it?

NIF-0709-16940 Presentation to MIT 48 Current hohlraum experiments are exploring a broad range of parameters

Effective laser-power Low-foot 1

0.8 CH 0.6

0 Hohlraum gas-fill 0.8 mg/cc 1.6 mg/cc

Low-foot

NIF-0709-16940 Presentation to MIT 49 Current hohlraum experiments are exploring a broad range of parameters

Effective laser-power Low-foot High-foot 1

0.8 CH CH 0.6

0 Hohlraum gas-fill 0.8 mg/cc 1.6 mg/cc

Low-foot

High-foot

NIF-0709-16940 Presentation to MIT 50 Current hohlraum experiments are exploring a broad range of parameters

Effective laser-power Warm Low-foot Rugby High-foot 1

0.8 CH CH CH CH 0.6 C5H12

0 Hohlraum gas-fill 0.8 mg/cc 1.6 mg/cc

Low-foot

High-foot Warm Rugby

NIF-0709-16940 Presentation to MIT 51 Current hohlraum experiments are exploring a broad range of parameters

These show reduced performance relative to the model Effective Model and laser-power Warm Low-foot Rugby High-foot HDC experiment 1 are in good agreement 0.8 CH CH CH CH 0.6 C5H12 Near vacuum

0 Hohlraum gas-fill 0.8 mg/cc 1.6 mg/cc

Low-foot

Near High-foot vacuum Warm Rugby

NIF-0709-16940 Presentation to MIT 52 The National Ignition Campaign (NIC) is a four-step experimental plan for demonstrating ICF energy gain

Demonstrate Laser Performance

Demonstrate Hohlraum Performance

Demonstrate Capsule Performance

Integrated Test

NIF-0709-16940 Presentation to MIT 53 MostMost of of thethe experimentalexperimental requirements requirementsset by set the by the pointpoint design design havehave been been ~ met~ met individually individually

α Adiabat ~ 1.5 VDT ~ 370 Velocity V 2 RDT ~ 1.45 g/cm km/s

~ 1.5 V ~ 350-370 km/s R~ 1.2-1.3 g/cm2 Ablator TRAD >300eV DT Ice DT Hot RHS spot HS

< 100ng RMS hot spot shape < 10% But variable But variable

CH mix in hot RMS hot spot M Mix spot < 100ng shape < 10% Shape S

NIF-0709-16940 Presentation to MIT 54 NIF-0000-00000.ppt Edwards—APS DPP Oct. 30th , 2012 8 The National Ignition Campaign (NIC) is a four-step experimental plan for demonstrating ICF energy gain

Demonstrate Laser Performance

Demonstrate Hohlraum Performance

Demonstrate Capsule Performance

Integrated Test

NIF-0709-16940 Presentation to MIT 55 We finally have an implosion where a large fraction of the total fusion output is from α-particle self-heating LF LF 2 20 ρrfuel ~ 1.6 g/cm Yield from fuel compression Yield from self heating Nov 19, 2013 Energy delivered to DT fuel Compression yield ~ 9.1 ±0.6 kJ Self-heating yield ~ 8.4 ±0.9 kJ 15 Yield amplification ~ 1.9 ±0.15 HF HF

High-foot Thinshell 10 HDC Yield (kJ)

5 NIC (Low-foot) HF HF 2 ρrfuel ~ 1.1 g/cm 0 110608 110615 110620 110826 110904 110908 110914 111103 111112 111215 120126 120131 120205 120213 120219 120311 120316 120321 120405 120412 120417 120422 120626 120716 120720 120802 120808 120920 130331 130501 130530 130710 130802 130812 130927 131119 Shot number Plots + hot spot analysis courtesy of P. Patel NIF-0709-16940 Presentation to MIT 56 The predicted impact of the high-foot pulse- shape on the stability of the implosion is significant High-Foot High-Foot Low-Foot α = 2.8 α = 2.2 α = 1.45 195 um shell

175 um shell µm R~200

µm R~50

§ Lower growth in high-foot in RT § Thin shell mass remaining is still phase is because of larger L = acceptable level at ~6-8%

grad(ρ)/ρ and higher vabl § increase in fuel velocity by ~4-5%

T. Dittrich et al., PRL submitted (2013) H. Park et al., PRL submitted (2013) O. Hurricane et al., Nature, submitted (2013) We trade-off compression for resistance to instability

NIF-0709-16940 Presentation to MIT 57 All HF implosions exhibit low hot-spot mix

Yield vs. mix-mass Yield vs. DSR 16

10 CH CH HDC 131119 HDC 5x 130927 16 high-foot CH 10 3x 130812 131119 ρrfuel ≈ 20.3⋅ DSR 130927 M. Gatu Johnson, et al., 131212 Only low-foot CH Rev. Sci. Instrum. (2012) 130812 2x 130710 131212 15 10 111215130501 low-foot CH 130710 120131 120205130530 15 1.5x HDC 130501 111215 120417120321120920130802 10 120131 110908110914 130530 111112120205 120219 130802 120920 110904 120321 120126 110615 120417 130331 120802 Neutron Yield 110620 Neutron Yield 120219 120716 120316 120126130331120802 1.2x 120716 111103 120316 120720120808 110608 110826 120311 120808 120720 120311120405 120626 120412 120213120626 14 120422 14 120422 10 10

0 500 1000 1500 2000 2 3 4 5 6 7 CH mix mass (ng) DSR (%)

NIF-0709-16940 Presentation to MIT 58 Star Trek at the NIF

NIF-0709-16940 Presentation to MIT 59 Contact info

John D. Moody: [email protected] Opportunities: Post-doc positions Summer scholars

NIF-0709-16940 Presentation to MIT 60