May 2007

1. Experiments With Astrophysical Applications R. Paul Drake University of Michigan May 2007 Work supported by the U.S. Department of Energy under grants DE-FG52-03NA00064, DE-FG52-07NA28058 and othergrants and contracts

2. One way to accomplish shock acceleration From R.P. Drake, Physics of Plasmas, Nov. (2000) Plot is for achievable nD2 = 1.4 x 1018 cm-1 Parameters will increase with future, larger nD2

3. Why HED Lab Astro is important to NNSA • Providing trained young people • The scientific population at the NNSA labs is aging rapidly • Over the next few years the National Ignition Facility will need a new generation • I could have easily placed 5 new Ph.D.s this past year • Advancing NNSA-relevant fundamental science • Most work in the labs is programmatic • Universities have a role to play in doing detailed, systematic, fundamental work • Establishing a national community and national advocacy

4. Current projects • Supernova-relevant hydrodynamics • Blast-wave driven instabilities • On Omega (Carolyn Kuranz in NLUF talks) • On NIF • Kelvin Helmholtz • Relevant to astrophysics and ICF • On NIKE (Eric Harding at HESDUP session) • Radiative shocks • Interesting objects ! • Astrophysically relevant • On Omega • On LIL collaborating with team led by Claire Michaut • X-ray diagnostics

5. Most of our current work uses Omega One of our shots at the Omega laser Collaborators: LLNL – Remington, Robey, Miles, Edwards, Hansen, Froula, others LLE – Knauer, Boehly Arizona – Arnett Chicago – Plewa Stony Brook – Glimm, Zhang, Swesty NRL – Aglitskiy, Weaver France – Bouquet, Koenig, Busquet

6. Here is what such lasers do to a material • The laser is absorbed at less than 1% of solid density Rad xport, high-v plas Hydro, rad hydro From Drake, High-Energy-Density Physics, Springer (2006)

7. Shock waves establish the regime of an experiment

8. Supernova 1987A motivates scaled hydrodynamic instability experiments • SN 1987A • A core-collapse supernova • Early high-Z x-ray lines with large Doppler shifts • Early glow from radioactive heating • The issue is the post-core-collapse explosive behavior • In 20 years of simulations • Only one (Kifonidis, 2006) makes fast enough high-Z material • 3D simulations coupling all the interfaces where initial conditions matter are not feasible • NIF experiments can do this • Omega experiments address a single interface SN1987A, WFPC2, Hubble Kifonidis, 2003

9. Here is a typical target for our supernova hydrodynamics experiments • Precision structure inside a shock tube • Hydrodynamics: • L >> mfp; Re > 105; • small heat conduction & radiation Experiment design: Carolyn Kuranz

10. We build precise, innovative targets Side view Laser-driven surface Acrylic cone Gold cone 1 mm Targets: Mike Grosskopf, Donna Marion, Robb Gillespie, UROP team

11. We obtain data from two orthogonal directions Dec. 06 data at 21 ns Data and analysis: Carolyn Kuranz Mid-1990’s data

12. We are now observing the role of complex initial conditions in spike penetration Preliminary data on mix layer thickness Interferogram of complex surface on component provided by GA (analysis: Kai Ravariere) Data and analysis: Carolyn Kuranz

13. We collaborate with simulation groups to evaluate our results and validate codes • Work with the FLASH Center (Chicago), to include 3D adaptive modeling, has now begun. 3D FLASH simulations of recent experiments (density display) 7.5 ns 13.5 ns 19.5 ns Single eggcrate mode. Two-mode system.

14. We lead a team to prepare for HED hydrodynamics beyond simulation on NIF • The unresolved issue in exploding stars • The 3D behavior of a diverging explosion • With multiple, structured interfaces • This problem cannot be fully simulated with computers • Too big, too complex, high Reynolds number • NIF can do a very relevant experiment • Also can do transition to turbulence • Preliminary design-related simulations • At Michigan and LLNL • (Grosskopf) (Miles) • Builds on experiments at Omega National Ignition Facility

15. We create and study driven radiative shocks • Laser beams launch Be piston into Xe or Ar gas at > 100 km/s • Piston drives a planar shock • Radiography detects dense xenon • Gold grid provides spatial fiducial • Parameters • 1015 W/cm2 • 0.35 µm light • 1 ns pulse • 600 µm tube dia. 10 drive beams Strike Be disk Xe filled tube Grid Target: Mike Grosskopf, Donna Marion, Mark Taylor

16. We have radiographic images of these radiative shocks • Average velocity 140 km/sec from t = 0 to 14.6 ns from laser firing • Two Phys. Plasmas papers • Exploration of structure will be a next theme gold grid 63 µm shock Data and analysis: Amy Reighard target wall Shot 39927

17. Advanced diagnostics will measure much more • Thomson scattering Data • Collaboration with Dustin Froula and Siegfreid Glenzer of LLNL Target Target: Trisha Donajkowski, Mike Grosskopf, Donna Marion Data and analysis: Amy Reighard With Dustin Froula Design: Amy Reighard • Fitting to data gives • 110 km/s fluid velocity • ZTe = 12 x 300 eV • Te ≤ Ti ≤ 500 eV Paper in prep. for Phys. Rev. Lett.

18. We collaborate very extensively One of our shots at the Omega laser Collaborators: LLNL – Remington, Robey, Miles, Edwards, Hansen, Froula, others LLE/Rochester – Knauer, Boehly, Frank Arizona – Arnett Chicago – Plewa, Hearn, Meakin Stony Brook – Glimm, Zhang, Swesty NRL – Aglitskiy, Weaver France – Bouquet, Koenig, Michaut, Busquet Rochester – Frank Texas – Ditmire

19. Some highlights of the past year • Target innovations enabled completion of data set on Rayleigh-Taylor spike penetration • Moving toward advanced diagnostics of radiative shocks • Amy Reighard defended her Ph.D. • Published the first graduate text in High Energy Density Physics