Center for Radiative Shock Hydrodynamics Fall 2011 Review Introductory overview R Paul Drake

You will see how our priorities have been driven by a sequence of integrated UQ studies This first presentation Motivation and introduction to the physical system Overview of the past year and the project status Our major accomplishments in this year Simulation of the year-5 experiment (This presentation and more later) Combining models of varying fidelity for UQ (Holloway and Bingham) Completion of the laser package (Powell and Van der Holst talk) Test experiments with nozzles and elliptical tubes (Kuranz) Talks tomorrow and posters today provide many details Organized abstract book provided for posters Items in this color are directly responsive to 2010 recommendations

We find our motivation in astrophysical connections Ensman & Burrows ApJ92 Radiative shocks have strong radiative energy transport that determines the shock structure Exist throughout astrophysics SN 1987A Reighard PoP07 Talk less about scaling Cataclysmic binary star (see Krauland poster: but she is at a related experiment)

We are showing a visualization of CRASH 3.0 output on the TVs This has “solved” the morphology conundrum We can do runs that produce a wall shock but no protuberance We still do have more to learn about running with our laser package and other issues that matter Simulation details 0.8 µm effective resolution in 2D Multigroup diffusion (30 groups, 0.1 eV to 20 keV) 5 materials, 2 AMR levels, CRASH EOS & Opacity Also see scale models in the room Movie should be showing

A brief primer on shock wave structure Behind the shock, the faster sound waves connect the entire plasma Denser, Hotter shocked unshocked Shock velocity, us Initial plasma Mach number M > 1 Mach number M = us / csound

Shock waves become radiative when … radiative energy flux would exceed incoming material energy flux where post-shock temperature is proportional to us2. Setting these fluxes equal gives a threshold velocity of 60 km/s for our system: Ts4 ∝ us8 ous3/2 unshocked preheated shocked Material xenon gas Density 6.5 mg/cc Initial shock velocity 200 km/s Initial ion temperature 2 keV Typ. radiation temp. 50 eV

CRASH builds on a basic experiment Radiography is the primary diagnostic. Additional data from other diagnostics. A. Reighard et al. Phys. Plas. 2006, 2007 F. Doss, et al. Phys. Plas. 2009, HEDP 2010 Grid Schematic of radiograph See Kuranz talk

We’ve continued radiographic studies Bayesian analysis of tilt gives compression ~ 22 Doss HEDP, A&SS 2010 Shock-shock interactions give local Mach number Doss PoP 2009 Shape of entrained flow reveals wave-wave dynamics Doss PoP 2011 Thin layer instability; scaling to supernova remnants Doss thesis & to be pub. 3.5 ns 13 ns Radiographs 26 ns Credit: Carolyn Kuranz

Also making or analyzing other measurements Shock breakout from the Be disk X-ray Thomson scattering Papers in prep Kuranz et al. Stripling et al. Visco et al. Huntington et al. See Kuranz talk and poster

CRASH 3.0 has substantial capability Material & AMR Laser package Dynamic AMR Level set interfaces EOS Self-consistent EOS and opacities for 5 materials Use of other tables too Multigroup-diffusion radiation transport Electron physics and flux-limited electron heat conduction Log Density Log Electron Temperature Log Ion Temperature 3D Nozzle to Ellipse @ 13 ns

We’ve completed simulations of the year-5 experiment Shock at 13ns in Elliptical Tube This is the system we want to predict Elliptical simulations (H2D initiated): Van der Holst et al, HEDP Submitted 2011 Show movie 2 once through, then movie 3 Bart’s movie is 1.6 µm effective resolution, H2D initialized, MG Cassini oval (movie 3 is 1 µm resolution, H2D initialized, gray) 13 ns multigroup

Our “viewgraph norms” are a lot better than they were 600 µm 1200 µm Circular Elliptical tube tube nozzle nozzle 26 ns gray Switch from movie 3 to movie 4 Although things are not perfect, we are ready to proceed beyond viewgraph norms to serious predictive studies. 13 ns MG

We have accomplished a lot during the past year Code improvements Laser package EOS source increased adaptivity Progress on multigroup preconditioner Hydro scaling PDT scaling Implicit scaling with HYPRE Non-LTE Physics More papers Obtaining STA opacities Work on non-LTE effects SN/FLD comparison Experiments Early time radiographs Deeper analysis of shock breakout Year 4 experiments: large tubes, nozzles, first elliptical results Progress on X-ray Thomson scattering UQ and predictive studies Predictive method involving joint models Predictive study with joint models and calibration/tuning First run set with laser package Evaluation of AMR fidelity Evaluation of sensitivity to opacity Code comparison project Steady though slow work on hydro validation Routine parallel scaling tests CRASH 3.0 released; CRASH used Base CRASH problem Elliptical tube Application to other experiments Hydro instability studies … Items in this color are directly responsive to 2010 review

We are organized and managed for success Strategic allocation of resources with tactical reallocation based on weekly meetings Ability to accomplish and improve our UQ work drives these decisions Some examples: focus on laser package, timestep controls, convergence We are managing around the UCNI problem Regular meetings of specific groups UQ, Applications, Software, Graduate students, Hydro Education items Having CRASH session and lunch/posters at APS/DPP to increase interactions with NNSA lab personnel and better disseminate CRASH developments Continuing to work with and recruit new students Continuing our educational programs in predictive science

There are areas in which we have not addressed prior recommendations Mostly this reflects following the recommendation to allocate resources strategically A list Lines of code coverage analysis Solution verification as distinct from the verification we have reported Computer bandwidth to the labs remains an issue It has improved by a large factor at LLNL PDT validation Management/Education Attempt to tightly coordinate students time at labs In some areas where we have made progress, resource allocation has limited our progress

We are in the age of run sets A substantial fraction of our activity Defining Initiating via a formal process Running (as platforms change) Processing Analyzing Reacting Many people & interactions RS 4: 104 2D on base expt RS 5: 512 1D on numerics RS 6: 128 2D on numerics RS 7: 128 99 for nozzles The final H2D runset (ugh!) RS 8: 27 2D Nozzle properties RS 9: 10 3D Ellipticity and shape RS 10: 128 2D base CRASH With laser package Future run sets discussed later Put up number 5: RS10_13 ns_cleanwide H2D could not get the job done

We’ve been burning up the cycles Running queue-limited much of the time Also burning a few x 100,000 core hours per month here at UM We’d crank up the output this next year if we were not limited by cycles, queues, and data transport H2D Core hours

Our predictive studies include a main path and supporting activities A sequence of studies that let us apply the joint model methodology to predict the year 5 experiment (see next talk) Supporting activities Solid verification practices Small studies focused on specific issues AMR, opacity impact, exact shape of 3D experiment, etc Validation and code comparison studies (see Fryxell talk) We are ready to make temperature measurements For the CRASH system From heat waves for validation (Gamboa poster) request review committee endorsement of this

Our roadmap for prediction is now based on 2D & 3D CRASH Newly completed RS 10 Multigroup (MG) is the foundation going forward (120 runs, 6360 observations) Expect to show improved prediction over last year May need to redo as laser package use matures 11/2011 – 1/2012: Complete RS10 Gray (G); combine G and MG to predict SL (shock location) & WSA (wall shock angle) 2/12 – 3/12: RS 11 – 2D G & MG with Nozzle 2/12 – 5/12: RS 12 – 3D Gray with Oval tube; construct predictive model for SL & WSA; select best next points to compute 6/12 – 7/12: RS 13 based on RS10 – 12; construct predictive model for SL & WSA

We are moving forward to complete the project Our code is of sufficient quality The laser package is the final key development We have demonstrated that we can do the necessary run sets We have done a run set with the laser package We have developed the methods to assess predictive capability We are ready to apply them to the year 5 experiment Our experiments are in a position to test our predictive capability and expand our validation data

Supplemental material follows

Our experimental sequence will improve and test our assessment of predictive capability A conceptually simple experiment Launch a Be plasma down a shock tube at ~ 200 km/s Year 5 experiment Predict outcome and accuracy before doing year 5 experiment Goals Improve predictive accuracy during project Demonstrate a predictive uncertainty comparable to the observed experimental variability A big challenge and achievement

We’ve invested real effort in scaling CRASH hydro on BG/L PDT transport on BG/L Weak scaling