Fusion: Making a star on earth and the quest for the ultimate energy source to power the planet

Transcription

1 Fusion: Making a star on earth and the quest for the ultimate energy source to power the planet Dr. Mike Campbell Director, Laboratory for Laser Energetics (LLE), University it of Rochester Fusion Forum Alberta Canada Nov 4, 2017

2 Inertial Confinement Fusion (ICF) Physics and Technology of the Extremes

3 Fusion works! Thermonuclear weapon The stars (including our own!) We need to make it work in a Controlled manner in the laboratory

4 Desirable Features of Central Power Production Abundant fuel supply Globally dispersed The Environmentally acceptable No/minimal public hazards Minimal proliferation concerns Multiple applications Electricity Water Transportation fuels Heat - Hydrogen - Biofuels Other societal needs answer is FUSION!

5 P> Atm

6 Technology of the Extreme: Energy Sources that can compress their energy in space and time are the Drivers for ICF 1 million (10 6 ) joules in 10-9 sec is watts!! Lasers NIF (1.8MJ, 500TW)@ LLNL Omega (30 kj,30 TW)@ LLE Pulse Power Z (25 MA, 80TW)@ SNL Fusion research: ~1-15 times/12 hrs: energy: ~1-15 times/second

7 NIF concentrates The all Nation the energy Ignition NIF Indirect-Drive Facility in a football can concentrate Baseline stadium- Target ~ 2MJ sized facility into and a 500 mm3 TW ( 5 x 4MJ 10 m Watts) of (I.R) laser energy and power in ~10-20 nsec 1.8MJ m x 10-8 (U.V) sec) onto a fusion target of ~1mm 3 and Ignition fusion campaign fuel mass in 2010 of ~1mg - 1.3MJ(0.35 m);q~15 target gain

8 The set for a 23 rd Movie!! Laser bay Century Target bay But not powered by Fusion!!!!

9 An ICF target can be thought of as an imploding rocket -rocket fuel (ablator) Energized by the laser -Payload (Fusion fuel) Total Mass: ~10-3 grams Final rocket (imploding) velocity~ 10-3 of light speed (~200 miles/sec)

10 In Inertial Confinement Fusion, a shell of DT fuel is compressed radially, and ignites from a central hotspot ~2-4mm Irradiation Compression Ignition Burn Target is irradiated by High intensity it EM radiation (~10 15 Watts/cm 2 ) that heat surface, forming a plasma (ablation) Fuel core is compressed dby the rocket-like blowoff at the surface (= spherical piston) Fuel core ( hotspot ) reaches ~10x temp. and density of the sun and ignites Fusion process propagates through fuel yielding many times the energy It s really just a nuclear diesel engine where the piston is made of the nuclear same fuel!

11 Implosion is a pressure amplifier : ignition requires great finesse and a high convergence ratio (CR) Capsule with DT Fuel High quality Implosion CR~ 30 Alpha heating and ignition Compression heating Cold dense DT DT hot spot 2 mm 0.1 mm Required convergence depends on the energy coupled to the fuel

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13 There are presently three credible ICF approaches to achieving ignition/gain in the Laboratory

14 Status: where are we today?

15 Fusion research on NIF is presently focused on Indirect Drive Ignition requires high finesse, high *convergence ratio (~30) implosion Principal challenges: Avoiding laser plasma instabilities 1cm Controlling x ray drive symmetry Controlling hydrodynamic instability particularly seeded by the capsule support and fill tube capsule tent Fill tube *convergence ratio = Capsule radius / compressed hot spot radius

16 X-ray drive on NIF is approaching the burning plasma regime and has achieved fuel pressures>250 Gbars! Yield (kj) Ignition (with G>1 at NIF, ~ 2MJ) CH LF * Burning plasma : energy CH HF HDC SC deposited in DT hot spot by Capsule gain > 1 (~ kj) alpha particles exceeds compressional work Q ~1 burning plasma (~70kJ) Alpha heating (~28 kj) (March 2011) (NIC, 2012) (HDC, 2017) Lawson Criterion, Improved hydro stability, LPI and hohlraum drive symmetry (high foot, 2014/15) Improved hydro stability Degraded dby hydro hd instability and asymmetry

17 Laser Direct Drive couples ~5 more energy to the fuel then indirect drive and requires es fuel pressure e <150 Gbar Advantage: Lower convergence (~22 vs 35) Lower pressure Higher Yield(gain) Diagnostic access Challenge: Hydro instabilities noise sources from laser imprinting Higher growth rates Thin shells Laser-plasma instabilities 17

18 Omega experiments have imploded DT to 56 Gbar about ~40% of that Omega experiments have imploded DT to 56 Gbar about ~40% of that required for Ignition at NIF energies and scaled fusion yields > 250 kj

19 Omega Implosion design and 30 kj are hydrodynamically scaled from MJ NIF Overlay of 60 beams

20 The prospects of ignition/gain for the three ICF approaches will be reviewed In the time frame Indirect Drive Continued focus on central hot spot physics Fusion yields >50 kj Improvements in Engineering i features Fill tubes, support structures Hydrodynamic y limitations Hohlraum Physics scaling (Laser-plasma Instabilities) for Laser Energies >~2.5MJ Ignition? Direct Drive.

21 LLNL and LLE have recently completed a study to determine the conversion of NIF to symmetric illumination- Direct drive in indirect drive illumination geometry (polar direct drive) remains an option J. Lindl Book, page 157 Although indirect drive is the primary approach to ignition on the NIF, developments in direct drive have reached the point where this approach also looks quite promising. With the implementation of additional beam smoothing and more beam ports Nif can be capable of both indirect and direct drive. 21

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23 ICF IFE * IFE * Inertial Fusion Energy

24 When ICF ignition is achieved what next? For several decades the ICF Community has explored IFE Concepts NIF ppt Dunne - LDRD, September 7,

25 The technology of an IFE power plant will be very different from today s ICF facilities: Could the Wright Brothers have imagined the 787? A burning plasma is required to initiate and inspire fusion energy development 25

26 An attractive feature of ICF is that a variety of target concepts can be tested with the same driver

27 In addition to the mainline ICF concepts, advanced target designs are also being explored Indirect Drive Direct Drive Hotspot ignition = fast compression PW laser (10s ps) Indirect drive compression Polar Direct Drive Fast Ignition Indirect drive compression Laser powershock Ignition e- Time Impact Fast Ignition Direct drive shock ign. Two-sided Hybrid B Magnetized Targets DT DD Advanced Fuels

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29 Flexibility in blanket design allows a variety of missions to be addressed by IFE

30 International interest and efforts in ICF/HEDP are expanding

31 Laser MegaJoule (LMJ) in France will ultimately be a NIF class laser capable of ignition research

32 In addition to LMJ, Europe has an extensive suite of facilities for the study and applications of high intensity lasers LaserLab Europe In addition, ELI (Extreme Light Infrastructure) is a >$1B Program to develop and exploit Ultra-Intense lasers

33 China and ICF: The SG-III laser facility: 48 beams, 180kJ/3ns/351nm Planning is underway for a >MJ laser (SGIV)

34 Both Laser and Pulse Power facilities capable of ignition research are underway in Russia and China Pulse Power Facilities ( Russia, China)

35 National Security (SSP)

36 High Energy Density Physics: Matter at Extreme (Astrophysics, Planetary Physics; Condensed matter, Nuclear physics, Relativistic i Plasma physics) Quasi-isentropic compression of carbon St tress (M Mbar) 50 Ramp data 25 Previous solid state data NATURE Editorial Fe Opacity (156 ev, 6.9x10 21 cm -3 ) Laboratory-based experiments are sorely needed to complement the rapidly proliferating spectral data originating from the latest space telescopes smission Tran Red :data Blue: opacity model 9.0 Wavelength (Å)

37 ICF will require both peak and average power lasers Most laser based applications will require average power Examples: Laser based accelerators Material processing Radiation sources - X-ray and gamma ray - Energetic Particles Neutrons Ions (H +. C n+ ) Multi-GeV beams from 10 cm scale structures And IFE!

38 High peak and average peak power fsec lasers have the potential for a number of applications X-rays and THZ radiation

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40 IFE laser systems will be highly modular with unit cells producing ~ Joules enabling system innovation and wide participation Numerous applications will result

41 Einstein did more than Relativity!!! Even I could not have imagined all of these applications!

42 Fusion will require careers and dedication John Sethian Retired NRL Fusion researcher >35 years! 42

43 Opportunities for Canada Trained scientists and engineers (i.e Dennis Whyte) Laser science, technology, and applications for the unit cell of IFE Advanced manufacturing (targets) Energy System engineering Including harsh environments Applications Tritium science and engineering (production, extraction, safety, etc) Others?