1. Fast (de)compression capabilities and first experimental results at HPCAT HPCAT Workshop 2014
Jesse Smith
HPCAT

2. In static high pressure research, time is arbitrary
Time-an added dimension
In static high pressure research, time is arbitrary
P(t) P
10-3
Dynamic Compression
Static Compression
DAC, LVP
100
Strain Rate Gap

3. Time-an added dimension
Selected scientific challenges from HPCAT’s 2012 Workshop
Explore non-equilibrium transformations and phase boundaries
Elucidate dynamics, kinetics, and pathways of phase changes
Study system-dependent nucleation rates and crystal growth
10-3
Dynamic Compression
Static Compression
DAC, LVP
100
Strain Rate Gap

4. Apparatus and examples
16-IDB, the right tool for the job
Optimized beam delivery from source to sample
Remote, precise control of sample pressure
High-frequency imaging using latest-generation area detectors
High-throughput processing of large volume of data
Examples
Fast compression and equations of state
Rapid decompression and materials synthesis
Ultrafast (jump) compression for generating high strain rate
Cyclic (fast) de/compression for kinetics, relaxation, and rheology

5. Beam delivery—source
A high-energy 3rd generation storage ring is crucial
7 GeV
E(keV) ∝ E2(GeV)
Canted undulator configuration at HPCAT since 2011
Images courtesy Argonne National Laboratory

6. Beam delivery—x-ray optics
Cryo-cooled Si double-crystal monochromator
320 mm Kirkpatrick-Baez mirrors
Pt or Rh stripes
FWHM < 5 mm
Indices
Typical use
(111)
High flux
(220)
Nominal
(311)
High Q
Intercept ~0.5 x 0.5 mm2 30 keV
Focus down to ~4 x 6 mm2 (v x h)
You can see these assemblies during the HPCAT Tour on Saturday

7. Sample pressure control

8. You can see these apparatus during Saturday’s hands-on sessions
Sample pressure control—plug and play
“Standard” symmetric DAC
Assembly Section View
DAC cylinder
diamond sample chamber
DAC piston
60um PZT
Spherical washer assy
Threaded collar
Clamping tube
You can see these apparatus during Saturday’s hands-on sessions

9. Sample pressure control—precise, automated

10. You can see these detectors during the HPCAT Tour on Saturday
Detectors—last piece of the puzzle
From commercial IP scanners . . .
100 s
. . . to hybrid pixel array detectors
2.5 s
15 Hz
125 Hz
3 kHz
You can see these detectors during the HPCAT Tour on Saturday

11. Software
Automated peak and unit cell fitting with volume and pressure calculation
Simple, easy-to-use software for on-line image visualization
Automated image integration using simple macro capability
See how this process works during Saturday’s hands-on sessions

12. Apparatus and examples
16-IDB, the right tool for the job
Optimized beam delivery from source to sample
Remote, precise control of sample pressure
High-frequency imaging using latest-generation area detectors
High-throughput processing of large volume of data
Examples
Fast compression and equations of state
Rapid decompression and materials synthesis
Ultrafast (jump) compression for generating high strain rate
Cyclic (fast) de/compression for kinetics, relaxation, and rheology

13. Fast compression—equation of state
Mo+MgO
Pressure apparatus—membrane
Loading—500 psi/s (Helium)
P0 ~ 80 GPa
Pf ~ 210 GPa
Dt ~ 1.3 s
Compression rate ~ 100 GPa/s
Detector—Dectris Pilatus1M
Exposure period– 10 ms (100 Hz)
Exposure time—7 ms

14. Fast compression—equation of state
High-frequency imaging yields acceptable signal-to-background ratio
Average compression rate ~100 GPa/s
Peak compression rate ~240 GPa/s
High-density data yields extremely robust equation of state

15. Fast compression—thermal EOS
WOW! It’s an apple!

16. Fast compression—thermal EOS
Complete Mbar isotherm in a few seconds
External heated DAC at HPCAT

17. Fast decompression—materials synthesis
Pressure apparatus—membrane + fast release
Unloading— psi (maximum rate)
P0 ~ 20 GPa
Pf ~ 0 GPa
Dt ~ tens to hundreds of ms
Decompression rate ~ GPa/s
Detector—Dectris Pilatus1M
Exposure period–arbitrary
Exposure time—arbitrary

18. Ultrafast (jump) compression—strain rate
Mo+MgO
Pressure apparatus—dDAC
Loading—1000 V (minimum rise time)
P0 ~ 151 GPa
Pf ~ 194 GPa
Dt ~ 1.25 ms
Compression rate ~ 34 TPa/s
Detector—Dectris prototype (Eiger 1M)
Exposure period– 1.25 ms (800 Hz)
Exposure time—1.23 ms P t
Before
After (Dt=1.25 ms)

19. Strain rate on the order of 101 s-1
Ultrafast (jump) compression—strain rate
Strain rate on the order of 101 s-1
Even on ms time scale, signal-to-background is useable, no sign of significant peak broadening

20. Fast, cyclic de/compression
Time

21. Relaxation of the KCl sample under fast (de)compression
Fast, cyclic de/compression
Relaxation of the KCl sample under fast (de)compression
Piezo drive FWHM of (200)
Fast compression experiments in radial diffraction geometry:
KCl as an example
Rheology
Deformation
Relaxation

22. Current challenges and future prospects
Selected Scientific challenges identified in 2012 Workshop
Explore non-equilibrium transformations and phase boundaries
Elucidate dynamics, kinetics, and pathways of phase changes
Study system-dependent nucleation rates and crystal growth
Technical challenges
Discrepancy between pressure loading and sample pressure
Limitations in pressure range and cyclic repeatability of dDAC
Time-dependent response of pressure media and/or marker
Future prospects
Order of magnitude flux increase leading to improved time resolution
Real-time pressure monitoring from x-ray marker
Closed-loop dDAC operation for robust and repeatable P cycling
Higher frequency, greater sensitivity area detectors with better E resolution

23. Contributors and acknowledgments
P(t) development: Chuanlong Lin, Eric Rod, Stanislav Sinogeikin, Guoyin Shen
ID-B staff : Yue Meng, Ross Hrubiak, Curtis Kenney-Benson
Software Development: Przemek Dera
User Collaboration (partial list): Jodie Bradby and Bianca Haberl; Nenad Velisavljevic, Dana Dattlebaum, and Raja Chellappa; Hyunchae Cynn and Zsolt Jenei; Choong-Shik Yoo and Dane Tomassino
This work was performed at HPCAT (Sector 16), Advanced Photon Source (APS), Argonne National Laboratory. HPCAT operations are supported by DOE-NNSA under Award No. DE-NA and DOE-BES under Award No. DE-FG02-99ER45775, with partial instrumentation funding by NSF.  The Advanced Photon Source is a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.