LFEX High Energy Peta-Watt Laser and Its Potential for High Field Science
Hiroshi AZECHI Institute of Laser Engineering, Osaka University
2013. 11. 18.
Fast Ignition Program Basic Science
11 Fast Ignition
Compression Fast heating Ignition and Burn
D+T→n+3He
Compactness of fast ignition will accelerate inertial fusion energy development. 2 Fast Ignition Realization EXperiment
GEKKO XII
LFEX
So far, 1 keV achieved. LFEX: 10 kJ/10 ps (4kJ/1ps) in 4 beams Ignition temperature to be achieved. 3 Strategy towards Fusion Power Generation
～2015 ～2025
FIREX-I: Ignition Temp FIREX-II: Ignition&Burn
Atomic Energy Commission of ～2035 Japan reported (Oct. 2005):
“Based on its (FIREX-I) achievement, decide whether it should be advanced to the second-phase program aiming at the realization of ignition and burning” *Laboratory Inertial Fusion Test LIFT: Power Generation 4 Are we ready?
✓ Reactor Core Plasma Reactor Technology Elements Laser Target injection and tracking Reactor System
Basic Science
5 Yield increase
2010-2011 exp’t ★ 20% ● 2002 results 10% 5% 3%
with Pre-plasma
Shiraga P.Tu_48 6 Temperature increase
Ignition Temperature
? 20% 10% 5% 3%
with Pre-plasma
The coupling efciency decreases at higher intensity. 7 Full operation of LFEX on Nov. 2014. GratingsGratings in in thethe compressioncompression chamberchamber ILILEEOOSSAAKKAA
575 nm
1919
Manufacture recovered three years after Earthquake. 8 Four Campaigns in three years
FY2012 FY2013 FY2014 FY2015 4 7 10 1 4 7 10 1 4 7 10 1 4 7 10 1 3 beams 4 beams Laser Development DFM1 DFM2
Campaign 1 Heating Basics
Heating Scaling Campaign 2
Campaign 3 Heating Scaling
Ignition Campaign 4 Temperature
9 Are we ready?
Reactor Core Plasma ✓ Reactor Technology Elements Laser Target injection and tracking Reactor System
Alliance
10 From Flush Lumps to Laser Diodes
Flash Lamps Laser Diodes
Laser Diodes
Broad emission spectra Emission matches absorption line Inefcient & low rep 1x1.5 cm^2 5-kW module 15 k$→500 $
high efciency and heat suppression 11 From Glasses to Ceramics
Laser Glasses Yb: YAG Cooled Ceramic Crystal
60mm
18mm
60mm
・Glass→Large optics ・Crystal→High thermal cond. ・Glass→Very low thermal conductivity ・Ceramic→Large optics
Several 100s increase of thermal conductivity enables 500 Hz rep rate, much higher than reactor requirement. 12 Target Injection and Beam Pointing
200µm
19 20 21
13 Industry’s Engagement into IFE Field
President Emeritus, Shoichiro Toyota, visited ILE, Osaka
Air & Water Jet Loom@ Toyota Techno Museum
Hirano Toyota Washida Azechi
Wept injection: >10 Hz, 80 m/s < Reactor Core Plasma Reactor Technology Elements Laser Target injection and tracking Reactor System ✓ Basic Science High magnetic field Nuclear Synthesis Acceleration 15 High magnetic field by high energy lasers - - - electron - GEKKO XII kJ-ns pulses! - Plasma - - current B 16 10 kTesla field by high energy lasers 1 kT magnetic field observed 10 kT magnetic field infered by Faraday rotation at coil center 1000 1 8 7 7 6 6 0.85 mm 5 5 4 4 λL = 0.53 µm 3 3 2 2 λL = 1.053 µm 0.1 100 8 7 7 6 6 5 5 4 4 Faraday 3 3 rotation density PeakBflux normalized 2 2 Pick-up probe measurement Maximum B flux density @ 850@ density Maximumµm B(T) flux 0.01 measurement 0.0 0.5 1.0 1.5 2.0 10 5 6 7 8 9 2 3 4 5 6 7 8 9 2 3 4 5 Distance from the coil (mm) 15 16 10 10 2 Intensity (W/cm ) 17 Magnetized Fast Ignition: Collimation I I B S. Fujioka O.Mo_A10 Bz,ext = 0! Bz,ext = 2 kT! 2.1ps! Bz 2.1ps! Fuel! nb! (cm-3)! de-collimating! field at interface! Simulation by J. Honrubia O.Th_A14 Necessary field is demonstrated. 18 Magnetized Fast Ignition: Collimation No Field Strong Field Current 1 angle Heating Laser Implosion Laser 4 4 2 2 1 1 Forward 8 8 6 6 4 20.9 deg. 4 2 2 Dose(PSL) Dose(PSL) Dose(PSL) 0.1 0.1 8 69.0 deg. 8 6 6 4 77.6 deg. 4 2 2 2 0.01 Low hν High hν 0.01 0 2 4 6 8 10 0 2 4 6 88 1010 IP Layer Number IPIP LayerLayer NumberNumber 19 Simulation Condition •Target plane Width 20~30 L Thickness 10 L Fast electron observation point Material Au with Z = 40 Electron density 50nc Pre-plasma scale 1 L from 0.1nc to 50nc Gaussian (5 m ) Johzaki O.Th_A15 50n 50ncr nc 50ncr cr E •External B-field k Bx (uniform) 0 ~ 10kT (0~100 MG) B0 100 10 c • n / 1 e 1 L n 0.1 • 05101520 x [ m] R-Wave penetrates deep into over-dense region. 20 Bx, By, Bz : instantaneous magnetic fields in x, y and z-directions EM-fields in cgs-Gauss unit are normalized by me0c/e. 8 For L = 1.06m, me0c/e ～ 10 1 /25 Landau quantized plasma Electron around! Electron around! Electron around ! Landau quantization B-field ! Nucleus! B-field 1 eV@10 kT BeppoSAX - - Pulsar: X0115+63 • 10-100keV NS – Electron or proton? – Electron B B 1012 gauss 10100 MT MT Ecycl≈11.6B12 keV – Proton B 1015 gauss 2mZ 2e4 eB E = − E = nω = n n22 c m 21 Landau quantization and Zeeman splitting: a few eV under 10 kT field. Energy diagram! Emission spectrum from white dwarf! ! Landau level and Zeeman splitting are Exotic atomic energy state can be good measures of magnetic field in generated in our laboratory with 10 stars.! kT magnetic field! 1989MNRAS.236P..29C B = 0 T B = 10 kT Landau quantlization Energy splitting Zeeman 22 ARTICLE NATURE COMMUNICATIONS | DOI: 10.1038/ncomms2466 he response of atoms to high magnetic fields has been of The Hamiltonian for an electron in atomic hydrogen usually interest for many decades1–4. It has been suggested that applied is magnetic flux densities up to 105 T (1 gigagauss) exist on T 2 2 the surface of white dwarf and cataclysmic variable stars5–7. This p e H0 1 inference is based on a complex process that involves a ¼ 2me À kr ð Þ combination of modelling the pattern of flux around the where p i: is the momentum operator. When a hydrogen surface and up through the atmosphere of the star, and a ¼À r 2 search for transitions that are stationary with magnetic field2–4. atom is subjected to a magnetic field, we replace p in equation 1 by (p A)2, where A is the vector potential defined by B A. These models are then compared with astrophysical spectra. þ ¼ r  We now have, in units such that me e k : 1, Definitively extracting a magnetic field value from the ¼ ¼ ¼ ¼ comparison is challenging because the measured spectra are 1 1 2 noisy with many overlapping features, as can be seen from some H H0 p:A A:p A 2 ¼ þ 2 ð þ Þþ 2 ð Þ examples in Fig. 1. In some cases, predicted features are missing and in others there are extra features. Such discrepancies are where H0 is the zero-field Hamiltonian (equation 1), the second usually attributed to the inhomogeneity of the magnetic field term, H1, is linear in field and the last term, H2, is responsible for across the surface or line-of-sight, and possibly species other than the quadratic Zeeman effect. The Hamiltonian of equations 1 and hydrogen. At the same time, there is controversy about how such 2 ignores spin orbit coupling and assumes the heavy ion mass high fields could even persist for any significant length of time8, limit, that is, it ignores the motion of the ion/donor. The general and the dearth of high-field magnetic white dwarfs (HFMWDs) case is considered in refs 20,21. In other species, different found in binary systems9. Identification of the observed spectral approximations are necessary. Given the above questions, and the features is further hindered at these fields because the calculation renewed interest in the high-field regime, it is crucial to validate of theoretical spectra where the magnetic cyclotron energy experimentally the theory for the absorption spectra on which the (:eB/me) is comparable to the coulombic binding energy inferred fields are based. Doing so directly for hydrogen is 4 2 2 (the Rydberg R mee /2k : , where k 4pe0) is non-trivial, impractical because the required fields are two to three orders of especially for atomic¼ species other than¼ hydrogen, such as magnitude beyond what is currently available in any helium10–12. The difficulty is that in the regime of interest laboratory22,23. Such tests become even more essential where 2 3 2 3 13–15 (BBB0 mee /2k : ) the Zeeman effect becomes quadratic , atomic species beyond hydrogen are being considered, for the spherical¼ symmetry of the Coulomb potential competes with example, helium10–12 or molecular hydrogen24–27 as for these the cylindrical symmetry of the magnetic field, and the cases the multiple particle calculations required are complex and Schrodinger equationnd is non-integrable, so producing quantum involve approximations (for example, basis-state choices and chaos16,17. The2 theory fororder the very complex Zeeman Zeeman structure in atsizes) high that are not a prioriB field guaranteed. atoms has been compared with laboratory absorption spectra in In low field, the Zeeman spectrum may be found from magnetic fields up to 8 T (refs 13–15). Although2 in Rydberg2 perturbation theory, the orbital and magnetic quantum numbers atoms the cyclotron energy can be more easilyp made equivalente to1 are constants of the motion.1 In this2 regime, B{B0 (half an atomic the substantially lower binding energyH (the characteristic field is punitA of field)A thep quadratic termA is negligible, and the transitions 4 = − + ( ⋅ + ⋅ ) + lowered by a factor n where n is the principal quantum shift linearly with field because H1 ½LzBz produces the usual 18 2me kr 2 2 ¼ number) , the regime near B0 is receiving renewed interest linear Zeeman energy ½mB (where Lz is the component of because it has recently been shown that a new kind of magnetic angular momentum along B||z and m is the magnetic quantum chemical bond can be produced that supersedes the electronic number). At very high field, the Coulomb potential is the 19 st nd bond , creating new molecules such as HeHydrogen2. ! 1 Zeemanperturbation effect and again! there2 are Zeeman constants ofeffect motion,! but in the atom =1/2 m B ≠1/2 m B Photon energy (rydberg) 0.125 0.150 0.175 0.200 SDSS J2346+3853 100,000 T 1.0 SDSS J1030+0538 | 80,000 T 0.9 100,000 0.8 80,000 0.7 SDSS J1206+0813 57,000 T SDSS J0021+1502 | 27,000 T 0.6 60,000 0.5 0.4 Magnetic field (T) 40,000 SDSS J1251+5419 41,000 T SDSS J0211+2115 | 9,000 T 0.3 Cyclotron energy (rydberg) 0.2 20,000 0.1 1.5 2.0 2.5 3.0 1.5 2.0 2.5 3.0 1.5 2.0 2.5 3.0 Photon energy (eV) Photon energy (eV) Photon energy (eV) Figure 1 | Hydrogen Balmer spectrumB. for N. HFMWDs. MurdinThe spectraet al., are Nature taken from theCommunications, Sloane Digital Sky Survey 7Vol.. They have4, p. been 1469 flattened (2013). by subtracting a 4th order polynomial fit and inverted. Also shown are all theoretical Balmer series transitions—we have chosen the field values to produce the best 23 fit. No account has been taken here of the temperature or the spatial and temporal field inhomogeneity and this accounts for the difference in the field values quoted here when compared with fits from a full calculation7. The magnitude of the dipole matrix element, and the polarization are shown, respectively, by the length and colour of the lines (red, circular s polarization, Dm 1; green, linear pz, Dm 0; blue, circular s , Dm 1). þ ¼À ¼ À ¼þ 2 NATURE COMMUNICATIONS | 4:1469 | DOI: 10.1038/ncomms2466 | www.nature.com/naturecommunications & 2013 Macmillan Publishers Limited. All rights reserved. Amusement MirrorCusp!! Tokamak! 3 beams 3 beams 3 beams テキスト 3 beams Driven by ….! 3 beams 3 beams 104 times B field sustains 108 times density plasma: mm Tokamak!? 24 Neutron generation via (γ, n) y = 1.6594e+8 * x^(3.5156) R= 0.96134 109 108 Yn~E @fixed I 4 2 Yn~γ ~I 107 Y~E3.5 Photo-Neutron Yield Photo-Neutron 106 0.1 1 10 LFEX Laser Energy (kJ) 1022n/cm2/s can be achieved at full LFEX laser 25 NIF allows studies of nuclear physics ILE OSAKA in a plasma environment Charged-particle reactions (McNabb, Petrasso) 1040 Dense Hot 1-1000 g/cm3 kT=1-100 keV ) 27-33 2 10 { 25 22 Neutron Capture 10 10 Nucleosynthesis 1020 Flux (n/s/cm Flux High Neutron Flux ≈1027-33 cm-2 s-1 (fluence=1017-22cm-2) 100 LANSCE/WNR Reactor SNS NIF LFEX We have results from two different diagnostics showing that neutron capture experiments can be done at NIF right now by courtesy of Dr. Bernstein 326 Our goal is to develop a capability to perform astrophysical (n,γ) cross section measurements at NIF F. Kappeler et al., has shown that modeled (n,γ) cross sections have large uncertainties 170Yb 171Yb 172Yb 173Yb 5.04 keV 3/2+ x3 4 ns 169Tm 170Tm 171Tm 172Tm Goal: ±30% accuracy 1/2+ 171 = Prediction from 6 leading Tm modeling groups prior to x6 measurement = Measured value NIF @ 1014 neutrons crams 2800 years* of neutron capture into every shot Can we use NIF to study the effects of the HEDP on (n,γ) nucleosynthesis? *Busso, Gallino and Wasserburg, Annu. Rev. Astron. Astrophys. 1999. 37:239–309 by courtesy of Dr. Bernstein 2012-045806s2.ppt Bernstein — Science on NIF TRC, January 8, 2013 4 Nanotube Accelerator Concept:%M.&Murakami&(2013)% 28 Fig.%1 In[15]:= Nanotube Accelerator p@r_ , z_D : NIntegrate= @ Plot3D 1.5 HH1 @p@r, z - rL^2 BoxRatios D, 8r, + Hz - s Highly collimated and quasi-monoenergetic proton Ø -2.5, L^2 + 4 85, 8 2.5<, 8 r Sin@ , 4<, Mesh z, -4, xD^2L Ø 30 4<, PlotRange^-beam0.5, has been produced , AxesLabel 8s, -2 Ø 80, , 2<, 8 Suddle-shapeØ None CoulombD 8<, potentialx, 0, Pi ê 2 r dN dNr T = 5 z /dE 12 z dE dE 5 10 4 10 Out[16]= 8 T = 5 T = 4 3 5 z 6 2 Electrosta*c+poten*al 4 4 0 T = 3 32 2 2 1 31 Radial energy spectrum dN spectrum energy Radial 0 0 dN spectrum energy Axial 0 0 0.5 1 1.5 2 1 32 Proton kinetic energy E (MeV) Export 2 @"3dview .gif ", %D Fig.%4 r Potential well collimates and mono-energetize protons 29 Summary • Fusion provides limitless energy source, has no danger of nuclear runaway, and emits neither warming gas nor high-level radioactive waists. • Compactness of fast ignition will accelerate inertial fusion energy development. • LFEX provides a platform towards high field science. 30 400 people got together. 31