Maximizing reliability and information content of ramp compression experiments with in situx-ray characterization - (DE-NA0003902)
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Maximizing reliability and information content of ramp compression experiments w ith in situ x-ray characterization (DE-NA0 0 0 3 9 0 2 ) Todd C. Hufnagel and June K. W icks 2020 SSAP Symposium February 2 7 , 2 0 2 0
Student and post -doc team members
Dr. Vinay Rastogi (50%)
Connor Krill
B.S. 2019
LLNL summer intern
Dr. Nasim Eibagi (50%)
Dr. Melissa Sims
(started 1/20)
Sophie Lee (UG)
Denotes U.S. citizen
Publications and presentations
Publications: None to date (several in preparation)
Presentations:
1. T.C. Hufnagel, “Quantitative x-ray phase contrast imaging during dynamic deformation and fracture.” 2 1 st Biennial
Conference of the APS Topical Group on Shock Compression of Condensed Matter (SHOCK1 9 ), Portland, Oregon,
June 1 8 , 2 019 (plenary)
2 . T. C. Hufnagel, “Life and death of materials in the fast lane: Deformation and fracture under dynamic loading.”
Department of Materials Science and Engineering, Cornell University, Ithaca, New York, September 1 9 , 2 0 1 9 .
3 . T. C. Hufnagel. “Stuck in flatland: W hat to do w hen you can't do 3 D.” 2 0 1 9 Momentum Initiative W orkshop on
Advanced Probes and Data Analytics for Enabling 3 -D Imaging Under Dynamic Conditions , Santa Fe, New Mexico,
August 2 9 , 2019 (invited)
4 . T.C. Hufnagel et al. “Quantitative x-ray phase contrast imaging of granular media under dynamic impact.” TMS
Annual Meeting, San Diego, California, February 25, 2020 (invited)
5 . J. K. W icks. “In situ X-ray diffraction of metals and metal alloys under dynamic compression” The 27 th AIRAPT
International Conference on High Pressure Science and Technology, Rio de Janeiro, August 5 , 2 0 1 9 (invited)
6 . J. K. W icks. “Phase transitions and melting of SiC and MgO along the Shock Hugoniot” American Geophysical Union
Fall Meeting, San Francisco, California, December 11, 2019 (invited)
7 . J. K. W icks. “Novel Experiments for Understanding the Interior of Earth, Planets and Exoplanets” American
Geophysical Union Fall Meeting, San Francisco, California, December 11, 201 9 (invited)
8 . J. K. W icks. “Dynamic compression experiments to explore planetary interiors.” School of Earth and Environmental
Science, Seoul National University, Seoul, South Korea, January 10, 2020.
9 . J. K. W icks. “MgO-- the Simplest Oxide.” Department of Geological Sciences Seminar, Stanford University, Palo Alto,
California, February 11, 2020.
1 0 . J. K. W icks. “MgO-- the Simplest Oxide.” Department of Geological Sciences Colloquium, CU Boulder, Boulder,
Colorado, February 20, 2020.
Program objectives 1. Develop validated strength models and pressure-density relationships for w indow materials (especially diamond and MgO) for ramp compression to pressures above 1 TPa. 2. Develop analytical and softw are tools for interpretation and simulation of x- ray diffraction (XRD) and x-ray phase-contrast imaging (XPCI) experiments at high rates. 3. Train undergraduate and graduate students in experimental techniques and model development relevant to the NNSA mission. 4. Offer short courses in experimental high-pressure physics and in situ characterization that can be accessed by researchers both in person and via the w eb.
What is ramp compression, and why do we do it?
T. S. Duffy and R. S. Smith, Front. Earth Sci., 26 February 2019 | https://doi.org/1 0 .3 3 8 9 /feart.2 0 1 9 .0 0 0 2 3
Ramp compression with diamond & LiF windows
J. K. W icks et al. Science Advances 4 (4 ) eaao5 8 6 4 (2 0 1 8 )
10.1126/sciadv.aao5 8 6 4
Importance of window properties
Much of the information available
about behavior of materials under
ramp compression (e.g. P-t
history of the sample) is derived
indirectly using wave propagation
analysis of velocity signals (either
sample/window interface or free
surface).
Doing this accurately requires
detailed knowledge of the
behavior of the window materials
under ramp compression
J. K. W icks et al. Science Advances 4 (4 ) eaao5 8 6 4 (2 0 1 8 )
10.1126/sciadv.aao5 8 6 4
Characteristics of an ideal window material
1 . Transparent to high P
2 . W ell-characterized properties (equation of state)
along both shock and ramp compression paths
3 . W ell-defined refractive index as a function of
density
4 . W eakly scattering and absorbing (for x-ray
diffraction)
Ramp compression with diamond windows
Backw ards characteristic approach using
diamond free-surface velocity as an
input, w ith experimentally-determined
equation of state (below ).
Problem: Not w ell-characterized above
800 GPa, and becomes opaque above
elastic limit.
J. K. W icks et al. Science Advances 4 (4 ) eaao5 8 6 4 (2 0 1 8 )
10.1126/sciadv.aao5 8 6 4
Ramp compression with LiF windows
Pressure determination for ramp
compression experiments w ith LiF
w indow s.
Only useful to ~500 GPa due to a phase
transition or melting .
Forw ard modeling using iterative
hydrocode calculations to match measured
velocity of the sample/LIF interface.
J. K. W icks et al. Science Advances 4 (4 ) eaao5 8 6 4 (2 0 1 8 )
10.1126/sciadv.aao5 8 6 4Automated iterative forward modeling
Iterative forw ard modeling by hand
is tedious and slow .
W rote object-oriented Python
w rapper around HYADES
simulation w ith optimization to
enable near real-time data
reduction to determine sample
pressure.
Conner Krill (JHU B.S. 2 0 1 9 )
Collaborators: Suzanne Ali, Ray Smith (LLNL)Automated iterative forward modeling
One key aspect of the success of this
undergraduate student project was the
summer in Livermore, which allowed for him
to complete his work and add to the tools
used by both Livermore and Hopkins.
For example, he left behind a GUI for us to
set up HYADES runs in multiplet.
Connor at LLNL Aug
2019Phase transition behavior of MgO under ramp
● In order to better exploit MgO as a w indow
material, w e need understanding of:
○ Phase transition boundaries
○ Anisotropy in strength and phase transition
kinetics
● Conducted preliminary experiments through
time in the LBS program for Fe-Si ramp
compression (Smith, LLNL and W icks, JHU)
B1 structure
(NaCl, rock salt)
B2 structure
(CsCl)
Diagrams from WikipediaPhase transition behavior of MgO
On shock compression MgO basically stays
a single crystal on shock compression in the
B1 stability field.
We can describe the B2 observed patterns
as fiber texture, which would support a
Buerger-type transition mechanism
J.K. Wicks et al. (in prep) Sims PRB (1998)Phase transition behavior of MgO Data collected at Omega January 2020 – preliminary analysis of MgO[100]
X-ray phase contrast imaging (XPCI)
Absorption contrast Phase + absorption
(radiography) contrast
Quartz single crystal imaged with
increasing propagation distance
(APS/DCS)Modeling x-ray phase contrast image formation
Model of object XPCI image3D information encoded in XPCI
Modeling x-ray phase contrast image formation
Represent features (voids, particles)
as randomly-oriented ellipsoids
Power spectrum of ellipsoids
maps on to spherical power spectrumExample: Dynamic wedge impact on sandstone
Moving forward: ML analysis of XPCI data Done: Python translation of code for XPCI simulation of virtual microstructures Beamtime scheduled for April 2020 for collection of training and validation XPCI data (APS Sector 2)
Plans for the coming year
1. MgO window development
a) Improve diffraction conditions (geometry and energy) for improved
azimuthal access to better understand B1-B2 transformation
b) Expand to other orientations (applying to Omega-EP through
LaserNet)
2. X-ray diffraction development
a) Crystallographic texture forward modeling
b) Build up student expertise in DCS/LCLS experiments
3. X-ray phase contrast imaging development
a) Collect x-ray CT data for training/validation of neural network (April
2020)
b) Building and train neural net
4. Workforce development
a) Bring on 1-2 new PhD students
b) Offer short courseYou can also read
