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Center for Radiative Shock Hydrodynamics

Fall 2011 Review

Introductory overviewR Paul Drake

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You will see how our priorities have been driven by a sequence of integrated UQ studies

This first presentationo Motivation and introduction to the physical systemo Overview of the past year and the project status

Our major accomplishments in this year o Simulation of the year-5 experiment (This presentation and more later) o Combining models of varying fidelity for UQ (Holloway and Bingham)o Completion of the laser package (Powell and Van der Holst talk)o Test experiments with nozzles and elliptical tubes (Kuranz)

Talks tomorrow and posters today provide many details o Organized abstract book provided for posters

Items in this color are directly responsive to 2010 recommendations

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We find our motivation in astrophysical connections

Radiative shocks have strong radiative energy transport that determines the shock structure

Exist throughout astrophysics

Ensman & Burrows ApJ92

Reighard PoP07

SN 1987A

Cataclysmic binary star(see Krauland poster: but she is at a related experiment)

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We are showing a visualization of CRASH 3.0 output on the TVs

This has “solved” the morphology conundrumo We can do runs that produce a wall shock but no protuberanceo We still do have more to learn about running with our laser

package and other issues that matter Simulation details

o 0.8 µm effective resolution in 2D o Multigroup diffusion (30 groups, 0.1 eV to 20 keV) o 5 materials, 2 AMR levels, CRASH EOS & Opacity

Also see scale models in the room

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A brief primer on shock wave structure

Behind the shock, the faster sound waves connect the entire plasma

Denser,Hotter Initial plasmaShock velocity, us

Mach number M > 1

unshockedshocked

Mach number M = us / csound

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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:

Material xenon gasDensity 6.5 mg/ccInitial shock velocity 200 km/s

shockedunshockedpreheated

Ts4 u∝ s

8 ous3/2

Initial ion temperature 2 keVTyp. radiation temp. 50 eV

CRASH builds on a basic experiment Basic Experiment: Radiography is the primary diagnostic.

Additional data from other diagnostics. A. Reighard et al. Phys. Plas. 2006, 2007F. Doss, et al. Phys. Plas. 2009, HEDP 2010

Schematic of radiographGrid

See Kuranz talk

We’ve continued radiographic studies

Radiographs

Shape of entrained flow reveals wave-wave dynamicso Doss PoP 2011

Thin layer instability; scaling to supernova remnantso Doss thesis & to be pub.

13 ns 26 ns3.5 ns

Credit: Carolyn Kuranz

Bayesian analysis of tilt gives compression ~ 22o Doss HEDP, A&SS 2010

Shock-shock interactions give local Mach numbero Doss PoP 2009

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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

Laser package Dynamic AMR Level set interfaces EOS

o Self-consistent EOS and opacities for 5 materials

o Use of other tables too Multigroup-diffusion

radiation transport Electron physics and flux-

limited electron heat conduction

3D Nozzle to Ellipse @ 13 ns

Material & AMR

Log Density

Log Electron Temperature

Log Ion Temperature

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We’ve completed simulations of the year-5 experiment

This is the system we want to predict

Elliptical simulations (H2D initiated):

Shock at 13ns in Elliptical Tube

Van der Holst et al, HEDP Submitted 2011

13 ns multigroup

Our “viewgraph norms” are a lot better than they were

600 µm 1200 µm Circular Ellipticaltube tube nozzle nozzle

Although things are not perfect, we are ready to proceed beyond viewgraph norms to serious predictive studies.

1213 ns MG

26 ns gray

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We have accomplished a lot during the past year

UQ and predictive studies o Predictive method involving joint models o Predictive study with joint models and

calibration/tuningo First run set with laser packageo Evaluation of AMR fidelity o Evaluation of sensitivity to opacity o Code comparison projecto Steady though slow work on hydro

validationo Routine parallel scaling tests

CRASH 3.0 released; CRASH usedo Base CRASH problemo Elliptical tube o Application to other experiments o Hydro instability studies

• 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

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 meetingso Ability to accomplish and improve our UQ work drives these decisions

Some examples: focus on laser package, timestep controls, convergence o We are managing around the UCNI problem

Regular meetings of specific groups o UQ, Applications, Software, Graduate students, Hydro

Education items o Having CRASH session and lunch/posters at APS/DPP to increase

interactions with NNSA lab personnel and better disseminate CRASH developments

o Continuing to work with and recruit new studentso Continuing our educational programs in predictive science

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There are areas in which we have not addressed prior recommendations

Mostly this reflects following the recommendation to allocate resources strategically

A list o Lines of code coverage analysiso Solution verification as distinct from the verification we have reported o Computer bandwidth to the labs remains an issue

It has improved by a large factor at LLNLo PDT validation

Management/Educationo Attempt to tightly coordinate students time at labs

In some areas where we have made progress, resource allocation has limited our progress

0.02 0.04 0.06 0.08 0.1 0.12200

300

400

500

600

700

Electron flux limiter

Tube Radius

µm

We are in the age of run sets A substantial fraction of our

activityo Definingo Initiating via a formal process o Running (as platforms change) o Processing o Analyzingo 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

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

Cor

e ho

urs

H2D

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Our predictive studies include a main path and supporting activities

Main patho A sequence of studies that let us apply the joint model

methodology to predict the year 5 experiment (see next talk)

Supporting activities o Solid verification practices o Small studies focused on specific issues

AMR, opacity impact, exact shape of 3D experiment, etco Validation and code comparison studies (see Fryxell talk)o We are ready to make temperature measurements

For the CRASH system From heat waves for validation (Gamboa poster)

request review committee endorsement of this

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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)o Expect to show improved prediction over last yearo 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

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We are moving forward to complete the project

Our code is of sufficient qualityo The laser package is the final key development

We have demonstrated that we can do the necessary run setso We have done a run set with the laser package

We have developed the methods to assess predictive capabilityo 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

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Supplemental material follows

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Our experimental sequence will improve and test our assessment of predictive capability

A conceptually simple experimento Launch a Be plasma down a

shock tube at ~ 200 km/s Year 5 experiment

o Predict outcome and accuracy before doing year 5 experiment

Goalso Improve predictive accuracy

during projecto Demonstrate a predictive

uncertainty comparable to the observed experimental variability

o A big challenge and achievement

We’ve invested real effort in scaling

CRASH hydro on BG/L PDT transport on BG/L

Weak scaling