Publications

Crystal spectroscopy of silicon aero-gel end-caps driven by a dynamic hohlraum on Z

Nash, Thomas J.; Sanford, T.W.L.; Mock, R.C.; Leeper, Ramon J.; Chandler, Gordon A.; Bailey, James E.; Mckenney, John M.; Mehlhorn, Thomas A.; Seaman, J.F.; McGurn, John S.; Schroen, D.; Russell, C.; Lake, P.E.; Jobe, D.O.; Gilliland, Terrance L.; Nielsen, D.S.; Lucas, J.; Moore, T.; Torres, J.A.; Macfarlane, Joseph J.; Apruzese, J.P.; Chrien, R.; Idzorek, G.; Peterson, D.L.; Watt, R.

We present results from crystal spectroscopic analysis of silicon aero-gel foams heated by dynamic hohlraums on Z. The dynamic hohlraum on Z creates a radiation source with a 230-eV average temperature over a 2.4-mm diameter. In these experiments silicon aero-gel foams with 10 - mg/cm3 densities and 1.7-mm lengths were placed on both ends of the dynamic hohlraum. Several crystal spectrometers were placed both above and below the z-pinch to diagnose the temperature of the silicon aero-gel foam using the K-shell lines of silicon. The crystal spectrometers were (1) temporally integrated and spatially resolved, (2) temporally resolved and spatially integrated, and (3) both temporally and spatially resolved. The results indicate that the dynamic hohlraum heats the silicon aero-gel to approximately 150-eV at peak power. As the dynamic hohlraum source cools after peak power the silicon aero-gel continues to heat and jets axially at an average velocity of approximately 50-cm/μs. The spectroscopy has also shown that the reason for the up/down asymmetry in radiated power on Z is that tungsten enters the line-of-sight on the bottom of the machine much more than on the top. © 2004 Elsevier Ltd. All rights reserved.