ILE, Osaka. Outline. • Introduction. – Fast ignition. – Gain estimation and the
emission. • Chamber and plant system. • Laser system. • Fueling system ...
Fast ignition Laser Fusion Reactor KOYO-F - Summary from design committee of FI laser fusion reactor -
ILE, Osaka
T. Norimatsu Institute of Laser Engineering, Osaka University IFE Forum Presented at US-Japan workshop on Power Plant Studies and related Advanced Technologies with EU participation
After the Roadmap committee, we organized a conceptual design committee to make the issue clear. In total, 34 working group meetings were held from March 2004 to Sep. 2005. • •
ILE, Osaka
Chair; A. Tomabechi Co-chair; Y. Kozaki (IFE, Forum) T. Norimatsu (ILE, Osaka)
Core plasma Working Group
Laser Working Group
Target Working Group
Plant system Working Group
H. Azechi
(ILE, Osaka)
N. Miyanaga
(ILE, Osaka)
T. Norimatsu
(ILE, Osaka)
Y. Kozaki
(IFE, Forum)
K. Mima
(ILE, Osaka)
K. Ueda
(U. Elec.Com.)
A. Iwamoto
(NIFS)
Y. Ueda
(Osaka U.)
Y. Nakao
(Kyushu U.)
Y. Owadano
(Nat. I. Adv. Ind. Sci.)
T. Endo
(Hiroshima U.)
K. Okano
(Cent. Res. Ins.)
H. Sakagami
(Hyogo U.)
M. Nakatsuka (ILE, Osaka.)
H. Yoshida
(Gifu U.)
T. Kunugi
H. Shiraga
(ILE, Osaka)
K. Yoshida
(Osaka)
M. Nishikawa
(Kyushu U.)
Y. Sakawa
(Nagoya U.)
R. Kodama
(ILE, Osaka)
H. Nakano
(Kinki U.)
S. Konishi
(Kyoto U.)
H. Nakano
(Kinki U.)
H. Nagatomo
(ILE, Osaka)
H. Kubomura
(Hamamatsu Co.)
A. Sagara
(NIFS)
T. Jhozaki
(ILE, Osaka)
K. Kawashima (Hamamatsu Co)
Y. Soman
Y. Suzuki
M. Nishikawa
(Kyushu U.)
(Laser Front Tech.)
(Kyoto U.)
(Mitsubishi Co)
T. Jitsuno
(ILE, Osaka)
Hayashi
(JAERI)
H. Fujita
(ILE, Osaka)
H. Furukawa
(ILE, Osaka)
J. Kawanaka T. Kanabe Y. Fujimoto
(ILE, Osaka)
M. Nakai
(ILE, Osaka)
(Fukui U.)
T. Kanabe
(Fukui U.)
Y. Fujimoto
( ILE, Osaka)
( ILE, Osaka)
K. Tsubakimoto (ILE, Osaka)
K. Tsubakimoto (ILE, Osaka)
Y. Furukawa
Y. Furukawa
(ILE, Osaka)
The committee is supported by IFE Forum and ILE, Osaka Univ.
(ILE, Osaka)
Outline ILE, Osaka
• Introduction – Fast ignition – Gain estimation and the emission
• Chamber and plant system • Laser system • Fueling system
Fast ignition is attractive , because the gain is high with a small laser ILE, Osaka
Processes for compression and ignition are separated. Laser irradiation
Compression
Ignition
Burn
Central ignition
Fast Ignition
Fusion Gain
100
Fast ignition
rh ρh < ρc/4 rc
Required gain for reactor KOYO (Osaka design) US-NIF 10
PW laser
Central Ignition
Fast heating of compressed fuel to create a hot spot at its edge
rh < rc/4 ρh ~ ρc
rc
1 0.1
1
Laser Energy （ MJ）
10
Fast heating needs petawatt laser. Critical issue is relativistic dense electron dynamics.
FIREX-1 project has been started to demonstrate Ti = 5 keV. ILE, Osaka
Gekko XII laser
LFEX laser 5
600 times liquid density and 1keV heating have been demonstrated ILE, Osaka
Power required 点火に必要と for ignition 予測されるパワー
0.8 keV
DD Neutron Yield
108 Heating 加熱効率30% efficiency 30%
106 0.4 keV
104
H. Azechi, LPB 91
Heating 加熱効率 efficiency 15% 15%
0.1 Heating Laser Power (PW) R. Kodama, Nature 01&02
1
Two-D simulation checked by implosion experiments at 実験によりベンチマークされた2次元シミュレーションにより，コーンターゲットに Rochester Univ. indicated that high density compression of おいても固体密度の2000倍以上の圧縮が予測されている． reactor-scale, cone target is possible. ILE, GA, Rochester ILE, Osaka 阪大ーGA共同研究 collaboration
S. Hatchet LLNL, APS/DPP '01
One of key requirements to start したがってFIREXを実施するキーディシジョン FIREX-II is satisfied. を下すことができる段階に入ったと思われる．
Although dynamics of cone-guided implosion is quite different from conventional spherical one, high ρR for ignition can be achieved
•existence of the cone causes non-symmetric slip boundary ablated plasma
ILE Osaka
ILE, Osaka
•implosion velocity
•shock hits the surface of the cone •timing of maximum density •hot spot
High gain will be achieved by increasing the laser energy at the same intensity. ILE, Osaka
FIREX-I Q~0.2 0.1
FIREX-II Q~8
Heating pulse
0.35-PW Electron Beam
Demo Q~150 By increaseing the core size, high gain will be achieved.
Johzaki 2003
Fast Ignition Gain Performance ρ = 300g/cc, α = 2 and 3 Energy coupling; ηimp = 5% for implosion & ηheat = 30% for core heating ILE, Osaka
In high gain region, target gain considerably decreases with increasing adiabat α. Wet wall reactor High-Gain
Gain, Q
100
α=2
Dry wall reactor
Self-Ignition
10
α=3 FIREX-2
1
FIREX-1 Driven-Ignition
0.1 10
100 ELtot [kJ]
1000
Outline ILE, Osaka
• Introduction • Chamber and plant system – Chamber structure – Pumping – Protection of final optics
• Laser system • Fueling system
KOYO-F with 32 beams for compression and one heating beam ILE, Osaka
•
Vertically off-set irradiation
•
Cascade surface flow with mixing channel
•
SiC panels coated with wetable metal
•
Tilted first panels to make no stagnation point of ablated vapor
•
Compact rotary shutters with 3 synchronized disks
The surface flow is mixed with inner cold flow step by step to reduce the surface temperature. ILE, Osaka
LiPb flow
Steel vessel
Thermal flow of KOYO-F ( One module) ILE, Osaka
LiPb cycle
300 MWe
Chamber Water cycle
300 ℃
300 ℃
50MW
70MW 210MW
Turbin
SG
70MW F2+F3 (80cm) 12.84 ton/s Average flow 7.8 cm/s
904MW
500 ℃
240MW
F１ (20cm) 8.56 ton/s Average flow 24.3 cm/s 80MW 80MW
ηther-elec=30%
500 ℃ Flow rate 21.4 ton/s
200MJ /shot x 4Hz
Specification of KOYO-F ILE, Osaka
Net output
1200 MWe (300 MWe × 4 )
Laser energy
1.1 MJ
Target gain
165
Fusion pulse out put
200 MJ
Reactor pulse rep-rate
4 Hz
Blanket energy multiplication
1.2
Reactor thermal output
916 MWth
Total plant thermal output
3664 MWth (916 MWth × 4 )
Thermal electric efficiency
41.5 %（LiPb Temperature ~500 C)
Total electric output
1519 MWe
laser efficiency Laser pulse rep-rate Laser recirculating power
11.4 % (implosion) , 4.2 % (heating), total 8% 16 Hz 240 MWe（1.2 MJ × 16 Hz / 0.08) Yb-YAG laser operating 150K or 220K)
Total plant efficiency
32.8 %( 1200 MWe/ 3664 MWth)
Estimation of Output Energy Structure 200MJ output (~1.2MJ driver; 1.14MJ imp + 71.5kJ heat) Case ILE, Osaka
④
89µm
③
① 200µm
(c) Output Power of Debris (thermal + Kinetic) leaking from each boundary ( ① ~ ④) 1E20
r
②
Core heating region
(b) Output Power of Radiation leaking from each boundary ( ① ~ ④ )
Output Power [W]
Z
Simulation box 400µm
(a) Output Power and Energy Spectrum of of α-particles leaking from each boundary (①~④)
Fusion Neutron Alpha Radiation Debris
1E19 1E18 1E17 1E16 1E15
0
50
100 150 200 Time [ps]
250
300
Summary of Burn Properties Input and output energies [MJ] for ~ 200MJ output case ILE, Osaka
Fusion [MJ] Carried out by Neutron※2 Alpha※3 Debris※4 Radiation error Gain
Opposite side (④)
1.12 1.14 0.0715 200 160 (80.0%) 11.8 ( 5.9%) 19.4 ( 9.7%) 1.85 ( 0.9%) 6.9 ( 3.4%)
④ Simulation box
12.7 1.31 2.26 0.12
MJ/str MJ/str MJ/str MJ/str
12.7 0.67 1.34 0.15
MJ/str MJ/str MJ/str MJ/str
165
※1 The energy coupling efficiencies of 5% and 30% were assumed for implosion and core heating, respectively. ※2 Neutrons were assumed to be freely and isotropically escaped from the core. ※3 Alpha particle: Leakage/Source = 29.8% (70.2% is deposited inside the core.) ※4 Constitution (energy D:35.5%, T:49.9%, α:14.3% / Number D:43.6%, T:44.5%, α:11.5%)
511µm
Driver Energy※1 Implosion Heating
Heating side (①)
Z
Energy [MJ]
117µm
③
r
② ① 258µm
The speed of ablated vapor 500 m/s at higher density region and 4000 m/s at the front. ILE, Osaka
(This work is on the way. Depends on the model for stoping range.)
10
6
10
5
10
4
10
3
Ablation Depth 10
102
tritium 5 alfa
0
500
1000
23
10
22
10
21
10
20
10
19
10
18
5000
1500
Time (ns)
0 2000
-3
Case 1 , R = 3 m Time = 2000 ns
4000 3000
Velocity
V=500m/s
V elocity (m/s)
10
10
)
R=3m
108 7
15
Ablation Depth µ( m )
Intensi ty (W/cm2)
109
2000
Number Density -2
-1
0
1
2
3
x (mm)
4
5
1000
0 6
P8
Total mass of ablated materials was 6.2 kg/shot including oblique-incidence effect. ILE, Osaka
z(m) 6
θ
3 4
r(m)
Lot of 0.1 µm radius clusters are formed after adiabatic expansion. ILE, Osaka
(Luk’yanchuk, Zeldovich-Raizer Model)
Future work: Hydrodynamic simulation including phase change is necessary to discuss the formation of aerosol. ILE, Osaka
Jet formation
t=2ms
t=10ms
70m/s 140m/s 250m/s
Size of evaporated vapor in flight
RT instabilities would form larger particles. -->
Four Pb diffusion pumps will be used to keep the chamber less than 5 Pa ILE, Osaka
Φ 0.45m
~ 0.4 x 0.3 x 0.4m each ~ 38 kg, 600 L/min 1 unit = 10 pumps (Total size:~ 1x1x1m for a unit)
Pb vapor 0.9 m
QuickTimeý Dz TIFFÅiLZWÅj êLí£ÉvÉçÉOÉâÉÄ Ç™Ç±ÇÃÉsÉNÉ`ÉÉǾå©ÇÈÇ…ÇÕïKóvÇ-Ç ÅB
Vacuum port
Pb diffusion pump
Dry scroll pump unit
Configuration of a vacuum pump set
6m Pb diffusion pump
LiPb 上部ﾌﾞﾗﾝｹｯﾄ 300 ℃
A
Dry scroll pump unit To Tritium process system
Inside: 1073K Pb liquid:673K Alumina vessel + metal jacket (Total size:~ Φ1x1m)
5m
Φ 0.55m
A’ 10000.00
A
9.4m3/s for air
φ6000.00
A'
Pb diffusion pump A-A' 断面図 LiPb液体壁チェンバ－概念図 1/100 単位mm Fusion output 200 MJ / pulse, 800 MW ,Pulse rep-rate s 4 Hz Chamber inner radius 3.0 m, upper wall distance from burning center 10.0 m Pulse heat load max. 32 J / cm2 , upper wall 2.9 J / cm2 average heat load max. 128 W / cm2 , upper wall 11.5 W / cm2 Neutron wall load max. 5.6 MW / m2, upper wall 0.5 MW / m2
Dry scroll pump unit （1 x 1 x 1m）
A set of 3 rotary shutters and buffer gas will be used to protect the final optics from the bluster wave. ILE, Osaka 32 Hz 16 Hz 4Hz
2500
Temperatrue of inner surface
(K)
Gas temperature (Local peak)
2000
Hole on 2nd disk
1500 Hole on 3rd disk
1000
Vapor
Wall surface 1st bluster wave from the wall
500 Blaster waves 1st shutter 32rps
v=150 m/s
v=3,000m/s @20,000K Open
2nd shutter 16rps 3rd shutter 4rps
Hole on 1st disk
Open Open
1 0 µs
100µs
Charged particlies from plasma 1 - 2 μ s alpha 0.2 - 0.4 μ s X-rays 10 ns
1ms
10ms Miss fired target
1 0 0m s Target injection
1s 2nd shot 3rd shot 4th shot
Vapor coming into the beam duct can be stopped with 0.1Torr D2 buffer gas. ILE, Osaka
0.5m
100m/s
•
The speed of vapor is decelerated from 100 m/s to 30 m/s before the plume breaks due to RT instabilities.
•
Mass of Pb vapor coming into the beam duct is10mg/shot, that means 1 ton/year！ Periodic cleaning in necessary.
Outline ILE, Osaka
• Introduction – Fast ignition – Core plasma
• Chamber and plant • Laser system – Cooled, ceramic Yb:YAG – Beam distributor
• Fueling system
Key technologies of laser for FI fusion plant ILE, Osaka
Foot pulse to form pre-plasma ・32 beams Controlled focus pattern ・2 ω ・wide band ・coherent during amplification in-coherent at focus point
Lasers 16Hz
Distributor
Heating pulse ・１beam coherently bundled ・ω ・wide band OPCPA ・Pulse compression Grating
Main pulse for compression ・32 beams Controlled focus pattern ・3ω ・ wide band Common technologies for compression and heating lasers ・ coherent during amplification ・main amplifier low-coherent at focus point laser material, LD Structure, optical shutter ・beam switching Laser：16Hz, reactor：4Hz ・Optics with multi-coating
Basic specification of lasers for reactor ILE, Osaka
Compression laser
Heating laser
Wave length
3ω
ω
Energy/pulse
1.1 MJ
100 kJ
Pulth width
TBD
30 ps
Pulse shape
Foot pulse + Main pulse
Flat top（2 ps reise time）
Beam number
32
1 bundle
F number
depends on plant design
F/10〜20
Uniformity
1 %（foot pulse）
-----
Spot size
Controlled focusing pattern
≤ 50 µm
Rep-rate
16 Hz
16 Hz
Cooled Yb:YAG was chosen for the laser material. ILE, Osaka
Compression laser Heating laser Main pulse
Foot pulse
Wavelength
UV (3ω) 343 nm
Visible (2ω) 515 nm
IR,1030 nm
Bund width
Narrow band
Wide band 1.6 THz
Wide band (Flat top pulse) ~3 nm
Efficiency
8 - 10 %
Not so important
~ 4%
Cooled Yb:YAG ceramic
Laser material
Method for wide bund
Arrayed beams with different wave length
One beam of arrayed beams
~0.1 nm@1030 nm (0.08 THz@343 nm)
pump light: 3w
Wide band OPA
Wide band OPCPA Large KDP pump light: 2w band width≈100nm
OPA: Optical Parametric Amplification OPCPA : Optical Parametric Chirp Pulse Amplification
Characteristics of Nd:YAG and Yb:YAG as materials for high power laser ILE, Osaka
Advantage of Yb:YAG Close wavelength of oscillating light to pumping light ⇒low heat generation
Long fluorescent life time of upper level ⇒easy to store energy
Wide absorption spectrum Life time
⇒ easy to pump with LD
Heat Life time
Heat
Wide fluorescent spectrum
⇒short pulse amplification
Disadvantage re-absorption
Small cross section for stimulated emission ⇒high saturation flounce
Quasi three level system
⇒energy loss due to re-absorption
Why cooled Yb:YAG? ILE, Osaka
Disadvantage Small cross section for stimulated emission
Larger cross section for stimulated emission ⇒Lower saturation flounce
⇒high saturation fluencies
Four level system Quasi 3 level system ⇒Gain loss due to reabsorption
⇒Higher efficiency with low pumping
Higher thermal conductivity ⇒Smaller thermal strength
⇒Appropriate characteristics for high intensity, average power laser
Cooled Yb:YAG ceramic is promising as the laser driver material Parasitic寄生発振限界 osc. limit
ILE, Osaka
Damage threshold 光学破壊限界
RT (W/cm)
Thermal shock parameter 熱ショックパラメーター
100 小口径 Small モジュール module
ceramics
10
crystal
望ましい領域 Optimal area
ceramics
Cooling Nd:YAG
Yb:YAG
?
Nd:SiO2
crystal Nd:Y:CaF2
Nd:CNGG
1
Disordered crystal
Yb:S-FAP Crystal
HAP4 LSG-91H BK-7 LHG-10 LHG-8 Glass
熱破壊 Thermal fracture
0.1 0.1 Artificial control of emission cross section
1
飽和パラメーター Saturation parameter
10 hν/σ (J/cm2)
Cooled Yb:YAG ceramic
2
100
Practical use of ceramic technology
Demonstration of high efficiency by cooling ILE, Osaka
Yb:YAG Yb:YAG LD for pumping LD 10 180K 940nm 580mW
(ROC 40mm)
光–光変換効率 74% Opt-Opt conversion efficiency スロープ効率 90%74%
Pumped areaφ 230µ m
30mm Vacuum vessel
1.4 kW/ cm2
Quasi 3 level system 3 941 nm
1030 nm
4 level 4system
941 nm
1030 nm
785 cm-1
0
