Center for Radiative Shock Hydrodynamics Fall 2011 Review

Laser Energy Transport and Deposition Package for CRASH

Fall 2011 ReviewBen Torralva1We developed the laser package to reduce uncertainty and enable productive UQ Perform simulations that reproduce the experimentally observed shock morphologyEliminate the use of H2DRezoner fidelity issuesDifferences between modelsH2D is manpower intensiveUQ is problematicCode revisions are slowDevelop a self-contained multi-physics modelReduce coupled-model uncertaintiesEnables more complete UQ studies

Experimental Radiograph

Auto-rezoner Comparison 2Title: We developed the laser package to reduce uncertainty and enable productive UQ

Laser energy transport is modeled using an efficient, parallel ray-tracing algorithm via geometric optics At each time step the rays are traced by numerically solving

using Boriss scheme, which automatically conserves the ray direction vector, The relative gradient, , can be determined from the plasma density distribution:

The critical density, ,at which the the refractive index goes to zero is

3Title: Laser energy transport is modeled using an efficient, parallel ray-tracing algorithm

Make definitions in different color and smaller f

Less words!Hit you will see UQ as driver. Laser energy is absorbed by electron-ion collisions The modify laser-plasma interactions cause laser energy to be deposited in the plasma. The dielectric permittivity becomes:

were the effective electron-ion collision frequency is

The absorption coefficient is calculated to be:

4Convert to overview. Hit you will see UQ as driver.

Move Boris scheme to previous slide.

Tile:Laser energy is absorbed by electron-ion collisions The laser energy is smoothly deposited in the plasma The electric field propagates through the plasma with the complex index of refraction , and At each time step the laser energy is deposited in the right-hand-side of the electron heat conduction equation to be solved implicitly

The delta-function is implemented by distributing the energy between the nearest cells with the total of the interpolation coefficients equal to one.

5Title: the energy is smoothly depositedWe verify the laser package nightlyThe laser-ray turning point and the energy deposition of an obliquely incident laser ray are tested.The closest approach to the critical surface is:

The energy deposition is:

is held constant, and at the critical surface.

Linear Density ProfileLaser Ray Absorption WeakLaser Ray Absorption Strong6Show density ramp picture and image pictureDont show equations. Keep as back up slide

Title: we verify the laser package nightly Shock breakout of 20 m Be foils are being simulated. Our experiments indicate that the average shock breakout is ~ 450 ps with systematic error of 50 ps. Convergence as a function of zone size

We tested convergence and scaling of shock breakout in 1-D

7Difference of the most highly converged to value as function of mesh size; log-log plot; error bar +/- 5psTalk through both graphs; less words that dont; 2 slides convergence and 1 for scaling. Title: We tested convergence and scaling of shock breakout in 1-DShock breakout occurs at ~ 400 ps in the modelThe laser intensity is scaled relative to the full CRASH intensity of 7x1014 w/cm2

8Difference of the most highly converged to value as function of mesh size; log-log plot; error bar +/- 5psTalk through both graphs; less words that dont; 2 slides convergence and 1 for scaling. Title: We tested convergence and scaling of shock breakout in 1-DCRASH shows more sensible behavior near the tube wall Comparison of breakout with H2D at the Au-Be-Xe interface

H2D at 0.7 ps Full CRASH at 0.88 ns

3 vs. 6 zones in auto-rezoner9Title: crash shows more sensible behavior near the tube wall

Move this slide up 1.; code comparison is verification

3 vs. 6 zones in the auto-rezonerWe validate the laser package in 2-D against shock breakout data 2-D breakout test of the full CRASH problem with a full-intensity laser profile and 2 levels of AMR

10Title: We validate the laser package in 2-D against shock breakout data.

Lable graphs

Make two slides one with movie; one that shows plots at the key point.2-D breakout test of the full CRASH problem indicates breakout at 420 ps with the full-intensity laser profile and 2 levels of AMR

Electron Temperature [keV] at 420 psR [m]Z [m]

Log Density [g/cm3] at 420 psR [m]Z [m]11Title: We validate the laser package in 2-D against shock breakout data.

Lable graphs

Make two slides one with movie; one that shows plots at the key point.We developed the laser package to reduce uncertainty and enable productive UQWe successfully implemented a laser energy transport and deposition package in CRASH The implementation is parallel, utilizes the Block Adaptive Tree Library (BATL), and adaptive mesh refinement (AMR)We conduct nightly verification tests of turning point and energy deposition of an obliquely incident rayWe are conducting code comparison and validation tests, and are simulating shock breakout experimentsWe are currently using this package in UQ studiesWe are developing full 3-D ray-tracing in 2-D and 3-D CRASH

12Make in active voice unless there is a reason not to

Make sentences