an introduction to proton-driven fast ignition · 2020.2.27 ssap 7 laser-driven ion-heating has...
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Chris McGuffeyUniversity of California San Diego
Stewardship Science Academic Programs 2020, Washington, DC
10 J 10 J
2020.2.27 SSAP 2
◦ Demonstrate isochoric heating of a solid sample using a significantly more energetic laser than previous studies in the literature.
◦ Evaluate the suitability of proton isochoric heating in making state measurements in a wider density range.
◦ Study the proton beam transport and stopping dynamics that are fundamental to heating a WDM sample using cutting edge computational tools.
◦ Improve our ability to measure WDM samples through development of diagnostic techniques.
2020.2.27 SSAP 3
University of California, SD◦ Joohwan Kim◦ Krish Bhutwala◦ Maylis Dozières◦ Adam Higginson◦ Farhat Beg
Lawrence Livermore National Laboratoryo Tammy Ma, Derek Mariscal, Scott Wilkso Jim Emig, Bob Heeter, Ed Marleyo Ronnie Shepherd, Ed Mageeo Paul Grabowski
This work was performed under the auspices of the National Nuclear Security Administration through DE-
NA0003876 (Joint HEDLP).
Laboratory for Laser Energeticso Wolfgang Theobald, o Phil Nilson, o Mingsheng Wei
CLPU, Univ. Salamancao Luca Volpeo Sophia Malko
General Atomics, SDo P. Fitzsimmons, o Sarah Muller, o L. Carlson, H. Huang, L. Gonzalez, J. Williams,
and D. Kaczala
2020.2.27 SSAP 4
Maylis DozièresPost-doc
spectroscopyexperience at
MEC, JLF, and OMEGA
Krish BhutwalaPh.D. studentPIC simulation
two summers at LLNLexperience at MEC,
JLF, OMEGA, and EP
Joohwan KimPost-doc
PIC simulationexperience at MEC, JLF, and EP
Adam HigginsonPost-doc
proton accelerationexperience at JLF
Dana Zimmer and Jackie Vaughanexperience at recent OMEGA EP day
2020.2.27 SSAP 5
Simulations with LSP hybrid PIC (K. Bhutwala poster, this conference) Simulations with PrismSPECT atomic collisional-radiation code Simulations with HYADES and HELIOS rad-hydro Analysis and manuscript preparation from past experiments Participation in NIF ARC proton heating experiment (T. Ma Discovery
Science) Participation in warm dense matter proton stopping power experiment (L.
Volpe, S. Malko CLPU) Application for OMEGA EP access (awarded, underway) Application for NIF+ARC access (not awarded)
2020.2.27 SSAP 6
A relativistically intense laser can rip the surface contaminants off of a foil target H2O, oil…
The proton beams have high power… High energy (10’s MeV, 10’s J) Short pulse (~1ps at source)
Schwoerer et al. Nature (2007) C. McGuffey submitted Sci. Reports
…and can be focused to high intensity Tight focus (<50 μm FWHM) Extreme current density (>109 A/cm2)
10 J 10 J
P.K. Patel et al. PRL (2003)
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Laser-driven ion-heating has been applied to isentropemeasurements of Equation Of State in recent major AWE and LLNL campaigns
Lasers can directly heat isochorically to hot states. Now, laser-driven ion sources can do it, too! Target Normal Sheath Acceleration is a highly studied regime Energy is absorbed via ion stopping; stopping power can be
very high in thin, dense matter The broad spectrum of ions means heating pulse duration is
determined by standoff
W. Bang, et al.,Sci. Reports (2015).
DJ Hoarty, et al., Sci. Reports (2012).M Hill, et al., APS DPP abstract UO7.006 (2018).
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The “Warm Dense” state can be reached with existing drivers WDM ≡ Temperature of ~ 1-100 eV, density of 0.01-100x solid WDM states are present in ICF implosions and stellar and massive planetary cores 17 J deposited = 10 eV per Cu atom in a 500 μm cube OMEGA EP and NIF ARC have delivered proton beams with >35 J*
*D. Mariscal et al. Phys. Plasmas (2019).R. W. Lee et al. LPB (2002).
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Type B, freestanding Type E, conical structureType F, wedge structure300 µmRc hemi
Trans. Layer +10 µm C
u
300 um300 um
FY14 coneFY13 wedge FY14 wedge
OMEGA EP Beam 2 (1250 J, 10 ps, 35 µm r80)normal incidence
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The separated target showed only a diffuse Cu Kα signal
The 10° wedge target produced a band through the middle
The 10° cone target produced a bright central spot
The signal is consistent with a central beam, not transport through the structure
200 μm cone hole
foil outline
200 μm wedge gap
hemi emission
PSL
C. McGuffey et al., submitted Sci. Rep.
2020.2.27 SSAP 11
A time-varying, superponderomotiveelectron source is injected on the hemi
TNSA ensues Er remains strong
for 18 ps It is present all along
the protons’ path
see J. Kim, et al., Phys. Plasmas (2018)
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The temperature reached in the simulation for the 10° cone was 100 eV Tighter focusing and 250 eV peak temperature predicted with a steeper, 20° cone
Z [μm]0 400300200100
R [μ
m]
0
200
100
R [μ
m]
200
100
-0.03
0.03
γβ┴
10° cone
20° cone
020° cone
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The intense proton beam driven by OMEGA EP (1.25 kJ, 10 ps) can heat samples into the Warm, Dense Matter state before significant expansion.
X-ray spectroscopy techniques can characterize the state of the sample; they have not been applied to proton-heated samples.
A well-characterized sample is required for future measurements of ion stopping power in the WDM regime.
Si is chosen here because of match with diagnostics. Si opacity is important to performance of some capsules.
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B1, 700J, 5ps
B2, 1250J, 10ps
TPS7
TPS83
PIC simulations predict the proton beam will heat the sample to 20 eV
PrismSPECT simulations predict numerous B-B absorption features sensitive to temperature
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absorption featurescold edge
MSPEC measured X-ray opacity of the Si K edge as protons heated the samplet=-78 ps t=45 ps t=113 ps
Thomson parabola and radiochroic film data recorded the proton spectrum
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high-power proton beams from CPA lasers can isochorically heat a sample ◦ ≫10 eV temperature and near-solid density simultaneously◦ a pathway for creating states that would be difficult to hit by shock compression alone◦ samples could be of interest for opacity, stopping power, equation of state
Protons can be focused with target design for extra intensity
A beam from OMEGA EP can heat Cu to 100 eV temperature◦ Verified on an LBS shot day 2018 (my presentation, SSAP 2019)
Time- and space-resolved X-ray absorption spectroscopy was applied to a proton-heated warm dense Si thin foil; temperature analysis pending
Chris McGuffeyUniversity of California San Diego
Stewardship Science Academic Programs 2020, Washington, DC
2020.2.27 SSAP 18
University of California, SD◦ Mathieu Bailly-Grandvaux◦ Farhat Beg
CELIA, Univ. of Bordeauxo João Santos
Imperial College Londono Francisco Suzuki-Vidalo Christopher Walsh
Universidad Las Palmas GCo Ricardo Florido
University of Nevada, Renoo Roberto Mancini
This work was performed under the auspices of the National Nuclear Security Administration National Laser User Facility program through award DE-NA0003940.
Laboratory for Laser Energeticso Jonathan Davies,o Jonathan Peebles,o Riccardo Betti
Sandia National Laboratoryo Taisuke Nagayama
General Atomics, SDo P. Fitzsimmons, o Sarah Muller
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Motivation:◦ Laser-driven, capacitor-coil targets (CCTs) are an inobtrusive means to
magnetizing HED plasmas such as a magnetized cylindrical implosion.
Goals:◦ Test CCTs up to 2 kJ laser drive energy and produce a B field of 50 T
◦ Characterize a cylindrical implosion with and without the applied field
◦ Test the validity of magneto-hydrodynamic (MHD) simulations ofimplosion trajectories
Team members: • Experiment: C. McGuffey, M. Bailly-Grandvaux, J. J. Santos, J. Davies,
J. Peebles, F. N. Beg, R. Betti
• MHD: F. Suzuki-Vidal, C. Walsh
• Atomic modeling: R. Florido, R. Mancini, T. Nagayama
J. J. Santos et al., (2015)
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TIM 3: CCT stalk
TIM 6: SXS
TIM 5: SXS
TIM 2: XRFCWhat we will do:• Implement a new CCT design compatible with
OMEGA implosions and 2 kJ drive• Measure neutron yield from cylindrical capsule
targets with 11 atm D2 fill.• Measure emission from Ar dopant in the fill gas.
Beam configuration:Laser SDD driver wavelength 0.351 μm Implosion shots:• up to 5 beams for each capacitor target from P4 and P9 ring 1• 40 beams for cylinder implosion: 345-415 J/beam, 1.5 ns
square pulse, SG2-600 phase platesB-field measurement shots:• up to 5 beams for each capacitor target• 20 beams for DHe3 capsule backlighter (400 J/beam, 1.5 ns
duration, no DPR nor DPP).
Primary diagnostics: • X-ray streaked spectrometer, High resolution X-ray
spectrometer, multiple X-ray framing cameras• SCC neutron scintillator• Proton radiography module and B-dot probes on proton
probing shots
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2.20 ns 2.40 ns 2.60 ns 2.80 ns
z [μ
m]
R [μm] R [μm] R [μm] R [μm]
*courtesy of C. Walsh, ICL
Stagnation @ 2.55 ns
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z [μ
m]
R [μm] R [μm] R [μm]
D2 ρ [g/cm3] D2 ρ [g/cm3]total ρ [g/cm3] total ρ [g/cm3]
z [μ
m]
z [μ
m]
z [μ
m]
Te [eV] Te [eV] B [kT]
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Simulated emission from the ABAKO collisional-radiative code* Stark-broadened line shapes calculated using the MERL code** Calculated for the average conditions of the middle 100 μm integrated along radial path Synthetic streak camera data shown
B0 = 0 T B0 = 50 T
*courtesy of R. Florido, ULPGC**courtesy of R. Mancini
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We are bringing the laser-driven capacitor-coil B field generators to OMEGA.
The B field will magnetize an imploding D2-filled cylinder based on the miniMagLIF platform.
Performance will be evaluated with neutron yield. Compressed conditions will be inferred from Ar (dopant) emission.
Shot day planned for September 3.
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S.N. Chen et al., Phys. Rev. Lett. 108 (2012). Proton radiographs showed filaments and
target sheath
T. Bartal, P-24 et al., Nature Physics 8 (2012), M.E. Foord et al., PoP 19 (2012). Ray tracing method of beam trajectories was
found to be insufficient A cone behind the target foil aids focussing
D.T. Offerman (P-24) et al., PoP 18 (2011). Carbon focusing investigated on OMEGA EP Also concluded focusing was nonballistic, invalidating the
ray tracing method We hypothesize that a 10 ps duration laser a cone would be an even more effective