target fabrications progress for … fabrications progress for megajoule laser experiments ......
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TARGET FABRICATIONS PROGRESS FOR
MEGAJOULE LASER EXPERIMENTS
12-16 MARCH 2017
22nd Target Fabrication Meeting | M. THEOBALD, JL. MIQUEL, L. JEANNOT, O. VINCENT-VIRY, C. CHICANNE, L. REVERDY, C. HERMEREL, C. DAUTEUIL, G. DE DEMO, S. MEUX, N. BOTREL, E. PECHE, P.VALOIS, A. BREVET, A. ZENTZ, L. GUILLOT, S. LOSSET, G.LEGAY, J.BRAY, N. CERMELLI, S. LE TACON, K.MOLINA, R. BOTREL, F. DURUT, S. ROCHER, R. CALAND, J. ANDRE, J. SCHUNCK, A. PINAY, A. GREGOIRE, I. GEOFFRAY, R. BOURDENET, M. MERLE, A. CHOBRIAT, O. RAPHAEL, P. MERILLOT, A. MAUBLANC, A.CHARPENTIER, A. CHOUX, V. DUTTO, L. BARNOUIN
OUTLINE
A short introduction of the LMJ facility status
Target fabrication progress:
We are developing a thematic approach on LMJ : a large panel of experiments will be done before
consolidating the ignition target design with dedicated experiments :
- A lot of different laser targets types are necessary
- Many fabrications developments (Microtechnologies, materials, characterization, assemblies…)
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LMJ FACILITY
ACKNOWLEDGMENTS TO J-L MIQUEL (PROJECT MANAGER) FO R HIS SLIDES
15 FÉVRIER 2017
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CEA | 10 AVRIL 2012
LASER MEGAJOULE MAIN CHARACTERISTICS
Target bayBiological protection : 2 m thick concreteTarget chamber Ø 10 m200 ports for laser beams and diagnostics
∅∅∅∅ 60m
H 38m
Ignition target
2 X 2 cones irradiation : 33°& 49°
Hohlraum length ~ cm
Capsule Ø ~ 2 mm
DT cryogenic layer
4 Laser baysGlass Nd laser, frequency tripled : λ = 0.35 µmDesigned for 240 beams, 176 will be installedLaser energy ~ 1.5 MJ, Power ~ 400 TWPulse duration : from 0.7 to 25 ns
The LMJ beamlines : most of the components have been qualified on the LIL prototype
M1SCF
Front end
Amplification Section
Transport, Frequency conversion and focusing
500 mJ
Spatial Filters
PEPC (plasma electrode
Pockels Cell)
4 passamplifiers
Deformable mirror
Angular multiplexing
15 kJ
Transport mirrors
TargetChamber
7.5 kJ UV50 µm15 ps
Frequency conversion & focusing system
Window + debris shields
1 & 2w beam dump
1 nJ
10 mJAmplifier
Regenerative cavity
Source
Phase plate
PAM
SID
Target bay : today equipment
RH TPS
Q28U
Q28L PW
beam
SID
Diagnostic Transfer Box
Intervention Vehicle
SIDDiagnostic :
3 m length30 cm diameter 150 kg weight20 µm precision
Chamber center Reference
7
LMJ schedule during the mounting phase
Three main activities are performed during the yearMounting of new bundlesActivation / qualification of the previous assembled bundlesPlasma experiments
Usually, only one shift is dedicated to experiments => 1 shot/dayWith both shifts, 2 shots/day have been obtained several time
In the next years : 50 Physics shots + 30 preparation shots (Diagnostic qualification, pointing, synchronization, …) per year
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
1st Shift
2nd Shift
Mounting
Experiments
Mounting
ExperimentsMounting
Mounting
ActivationQualification
Mounting
ActivationQualification
1-Hohlraum energeticsLaser plasma interaction,X-ray conversion ����Control of radiation flux
2-Fundamental dataEOS, Opacities…����Control of matter’s behavior under HP and HT
3-Radiation transportX-ray absorption, loss, reemission���� Control of energy transport
4-Implosion hydrodynamicsImplosion velocity, Shock tuning���� Control of compression5-Hydrodynamic Instabilities
Instabilities growth, turbulence���� Control of mixing
6-Fusion studiesThermodynamic conditions, initiation of fusion reactions ���� Control of ignition conditions
7-Ignition Study of different kind of ignition targets���� Control of DT burning
8-ApplicationsCoupling of an ignition target with another target���� Control of complex powerful system
The 8 experimental topics of the Simulation Program
TARGET FABRICATION
RECENT PROGRESS
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CEA | 10 AVRIL 2012
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WHAT IS TARGET FABRICATION ?
Specific materials
Machining
Assembly
Characterizations
Conception
Delivery
# 1 year
SPECIFIC MATERIALS : HOLHRAUMS
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See J. Andre’s poster
Additive manufacturing prototypeGold holhraums but not only…
Holhraums with liners
Complete liner Localized liner
Cu 1,5µm
Au 30 µm Cu 1,5µm
Au 30 µm
Mandrel machining
Sacrificial layer deposition and laser machine
PVD coating
Sacrificial layer dissolution
Electro-deposition
Mandrel dissolution
2017 Omega EP Experiments2017 LMJ ExperimentsCu holhraums
Addition of PVD and electrolytic coatings New process developed
SPECIFIC MATERIALS : FOAMS & AEROGELS
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60 mg/cc20 mg/cc 80-100 mg/cc 300 mg/cc40 mg/cc
SiO2 aerogels:
275-300 mg/cc 500 mg/cc110 mg/cc 800 mg/cc70 mg/cc
≤ 2015
2016
2017
Ta2O5 aerogels:
CHx 25 mg/cc
Development of new densities:
Development of new fabrication techniques: Understanding aerogels aging process and environmental conditions influence on density:
Casting to avoid machining and assemblies
dens
ity
agingDensity reversibility under vacuum
vacu
um
vacu
um
vacu
um
SPECIFIC MATERIALS : METAL FOAMS
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See R. Botrel’s talk
Optimization in progress (PhD) to obtain satisfyingmechanical resistance necessary to
machine this kind of very fragile materials
Structure and relative density can be controlled with ion salt concentration and overvoltage
C3,
U3+
10V
C3,
U3+
1Vfoam density strongly depends on ionic salt concentration � electrolytic phenomenon
CATHODE
Au3+
Streamer
Gold foam
SEM pictures of gold foams (same magnification)
Streamers are thicker when increasing overvoltage → foams with higher densities
plasma Electrolyte[Au]=C
Applied Potential = U + Overvoltage
breakdown voltage
Low density gold : plasma electrolysis
SPECIFIC MATERIALS : METAL COATINGS
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See S. Le Tacon’s poster
Spin-coating and Sputtering
500 nm2000 nm500 nm
Glass
Sacrificial layer
Al
Pr
Al
Al
Pr
Al
Al
Pr
AlAl
Pr
Al
Release Laser machining Self supported disk ∅8 mm
Praseodymium thin films
Developments with some collaboration with
Al/Pr/Al
Issues :- Reducing residual stress- Ageing : encapsulation between efficient
aluminum layers
High stress
Low stress
Al
Pr
Surface mass (g/cm²) characterization
No deviation over 2 months under air :- Al barriers are efficient- No stress evolutionThese membranes will be experimented early 2018 @ L MJAl/Pr/Al
SPECIFIC MATERIALS : CAPSULES (MANDRELS)
Injection : Syringe pump replaced by pressure-based flow controllers: higher flow stability, retro-control on flow rate variations
Curing : • Setting and monitoring installation
parameters and fluorobenzene concentration � Software development
• Measuring fluorobenzene concentration all along the curing process in each bottle (Coated quartz crystal microbalance developed by CEA Le Ripault)
A943 PAMS shell meeting expectations (50% yield)
PAMS Mandrels : improve yield
SPECIFIC MATERIALS : CAPSULES (GDP)See G. Legay’s poster
169,9 µm thick CHSi 4%at.Roughness optimization
Yield before polishing 20%
Yield after polishing 45%
After GDP coating After polishing
First capsules without any bumpsSome “light” scratches are observed inherent to polishing
Other “new” GDP studies :- New dopants (poster)- Asymmetric capsules
Ongoing work : Master the outside shape to fit a specific function
MACHINING
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In-situ run out correction on UP lathe
Z
X
Y
ϕϕϕϕ
θθθθρρρρ
Development of custom spindle neck with X/Y adjustment
Development of combined “turning” / “milling” by µ-EDM
Investigation in µ-EDM Development of a custom µ-milling machine (4 axis)
Tungsten carbide holhraum
Use the full potential of each process
Applications : Foam & aerogel complex shape machining
Compliant design, sub-micron adjusting capability
Adaptation of existing process to more flexibility
Milling in Low density foam
Applications : Machining of “hard” materials (steel, Ta, W, B4C,etc. )
Applications :- Run out correction - controlled shift of revolution axis
1 mm
See J. Andre’s poster
MACHINING : LASER
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Foam over-thickness < 5 µm
Surface finishingExcimer laser Femtosecond laser
UV pulsed laser193 nm / 50 Hz / 30 ns
Ti:Sa ultrafast laser800 nm / 1 kHz / 150 fs
Removal of foams layers on the surface of metals
Low density materials shaping.Example of Ta2O5 0,5 g/cc
Top/bottom diam.:200 µm / 400 µm
Optimized laser & motion parameters+ Specific mask shape
Cutting of rare-earth samplesunder dynamic vacuum
Controlled thermal effect on the edge(prevention of oxidation)
ASSEMBLYSee O. Vincent-Viry’s talk
Recasting of
optical systems
and command
control /
measurement
software
Turrets
motorization
Fast turret
positioning
New assembly station prototype
To face increasing target complexity and further increasing targets production
Specific automated stations : membrane gluing
� Adapt assembly stations to new target geometries and increase reactiveness� Focus technicians on valuable operations & automatize assistance on repetitive actions� Secure assembly operations (minimize sample manipulations)
Sucking nozzle for cone manipulation
Sucking nozzle for spherical ½ hohlraum manipulation
Tools : additive manufacturing
CHARACTERIZATIONS
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Quelques exemples de caractérisations pour les ciblesObjectives : 1. Secure our means2. Increase performance3. Purchase or develop new means to answer to our needs
See L. Reverdy’s talkV. Dutto’s posterO. Raphael’s posters
Spheremapper
Confocal probes
Sample holder
Movingstages
Calibration samples to compare AFM heads
Thin film thickness cartographer
Opaque or transparent samples
3D measurements
Xray tomographer
CRYOGENIC PROCESS
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DEVELOPMENT OF 2 cryostats IN COLLABORATION WITH CE A GRENOBLE
Cryoteci – D 2 cryostat
• Cryo-thermometers calibration• Keyhole target validation (liquid D2)• Useful temperature range is 15K-25K.
• Pulse tube as cold source• Double thermal shield
� last adaptations in 2017� Tests on real target in 2018
MVT-S – DT cryostat
• DT ice layer conformation studies• Temperature range 10 – 25 K• Stability +/- 1 mK
� Command control, gripper and thermal shield optimization in progress
� Delivery planed in 2 years @ Valduc tritium facility
• Pulse tube tandem for better stability
See F. Viargues’ poster
TRANSPORT TO EXPERIMENTATIONS SITES
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2 mm
1 mm
1 mm HED physic studies
2 mm
DAMDTRISMCI
Commissariat à l’énergie atomique et aux énergies alternatives
Centre de Valduc| 21120 IS SUR TILLE
T. +33 (0)3 80.23.53.01| F. +33 (0)3 80 23 52 77
Etablissement public à caractère industriel et commercial | RCS Paris B 775 685 01915 FÉVRIER 2017
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CEA | 10 AVRIL 2012
Thank you !