1. John Santarius and Greg Moses University of Wisconsin HAPL Project Meeting PPPL December 12-13, 2006 Effects of Long Mean-Free-Path Ions on Shock Breakout

2. JFS 2006 Fusion Technology Institute, University of Wisconsin 2 Ghost zone Hydro zone Ghost zone Hydro zone Null zone Ghost zone Hydro zone Null zone Ghost zone Hydro zone Gap between hydro zones has closed; zones get renumbered. In original conception, ghost zone pushed hydro zones apart; absorption can also occur. In the Original Conceptual Picture, Long Mean-Free Path “Ghost” Zones Move through Hydro Zones Ghost zones transfer momentum with those hydro zones through which they pass. Ghost zone Hydro zone Ghost zones now get renumbered.

3. JFS 2006 Fusion Technology Institute, University of Wisconsin 3 Zel’dovich & Raizer Shock-Breakout Problem Chosen for Code Development Zel’dovich & Raizer, Physics of Shock Waves and High-Temperature Hydrodynamic Phenomena, Chapter 25. Strong, spherical shock propagating through an exponentially falling density gradient.  Analogous to ICF shock propagating through the blow-off plasma. Initial velocities equal zero; mass density and temperature shown below.

4. JFS 2006 Fusion Technology Institute, University of Wisconsin 4 For Pure Hydro Motion, Velocities Get Unphysically High

5. JFS 2006 Fusion Technology Institute, University of Wisconsin 5 Gap (Null Zone) between Hydro Zones Fills Quickly because of Internal Pressure Hydro zones about to merge Ghost zones drag hydro zones upward in energy (and velocity).

6. JFS 2006 Fusion Technology Institute, University of Wisconsin 6 Slowest Ghost Zone Fades after a Short Time

7. JFS 2006 Fusion Technology Institute, University of Wisconsin 7 After a Short Time, Ghost Zones Nearly Free-Stream

8. JFS 2006 Fusion Technology Institute, University of Wisconsin 8 Status and Summary Mathematica ® code appears to move hydro and long mean-free path (ghost) zones properly for the simple Zel’dovich and Raizer test case. Momentum transfer between zones also appears to be working. A minor zone renumbering problem remains to be addressed. Next step is to use initial conditions from a HAPL test problem.

9. JFS 2006 Fusion Technology Institute, University of Wisconsin 9 Reserve Slides

10. JFS 2006 Fusion Technology Institute, University of Wisconsin 10 DT Core r shock (cm) < 0.001  r shock (cm) < 0.001 v shock (cm/s) 6.6 x 10 6 n i (cm -3 ) 1.5 x 10 26 T i (keV) 276 T e (keV) 72 Ave. charge state 1  r shock / mfp > 1000 DT Core DT-CH Shock r shock (cm) < 0.0010.026  r shock (cm) < 0.0010.02 v shock (cm/s) 6.6 x 10 6 5.5 x 10 8 n i (cm -3 ) 1.5 x 10 26 5.1 x 10 24 T i (keV) 27686 T e (keV) 7247 Ave. charge state 1 DT 1 CH 1  r shock / mfp > 10001.1 DT Core DT-CH Shock CH-Au Shock r shock (cm) < 0.0010.0261.1  r shock (cm) < 0.0010.020.004 v shock (cm/s) 6.6 x 10 6 5.5 x 10 8 8.6 x 10 7 n i (cm -3 ) 1.5 x 10 26 5.1 x 10 24 5.0 x 10 18 T i (keV) 276862.8 T e (keV) 72470.69 Ave. charge state 1 DT 1 CH 1 CH 1 Au 36  r shock / mfp > 10001.10.001 At 34.592 ns, the DT-CH Shock Thickness and Incoming Ion Mean Free Paths Become Comparable

11. JFS 2006 Fusion Technology Institute, University of Wisconsin 11 Qualitative Motion of Ghost and Hydro Zones Appears Reasonable