skip to main content

DOE PAGESDOE PAGES

Title: First beryllium capsule implosions on the National Ignition Facility

The first indirect drive implosion experiments using Beryllium (Be) capsules at the National Ignition Facility confirm the superior ablation properties and elucidate possible Be-ablator issues such as hohlraum filling by ablator material. Since the 1990s, Be has been the preferred Inertial Confinement Fusion (ICF) ablator because of its higher mass ablation rate compared to that of carbon-based ablators. This enables ICF target designs with higher implosion velocities at lower radiation temperatures and improved hydrodynamic stability through greater ablative stabilization. Recent experiments to demonstrate the viability of Be ablator target designs measured the backscattered laser energy, capsule implosion velocity, core implosion shape from self-emission, and in-flight capsule shape from backlit imaging. The laser backscatter is similar to that from comparable plastic (CH) targets under the same hohlraum conditions. Implosion velocity measurements from backlit streaked radiography show that laser energy coupling to the hohlraum wall is comparable to plastic ablators. The measured implosion shape indicates no significant reduction of laser energy from the inner laser cone beams reaching the hohlraum wall as compared with plastic and high-density carbon ablators. Furthermore, these results indicate that the high mass ablation rate for beryllium capsules does not significantly alter hohlraum energetics. In addition, these data,more » together with data for low fill-density hohlraum performance, indicate that laser power multipliers, required to reconcile simulations with experimental observations, are likely due to our limited understanding of the hohlraum rather than the capsule physics since similar multipliers are needed for both Be and CH capsules as seen in experiments.« less
Authors:
 [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [1] ; ORCiD logo [1] ;  [1] ; ORCiD logo [1] ;  [2] ;  [2] ;  [2] ; ORCiD logo [2] ; ORCiD logo [2] ; ORCiD logo [2] ;  [2] ;  [2] ;  [2] ;  [2] ;  [2] more »; ORCiD logo [2] ;  [2] ; ORCiD logo [2] ;  [2] ;  [2] ; ORCiD logo [2] ;  [2] ; ORCiD logo [2] ;  [2] ;  [2] ;  [2] ;  [2] ;  [2] ;  [2] ;  [2] ;  [2] ;  [2] ;  [2] ;  [3] ;  [3] ; ORCiD logo [3] ;  [3] ;  [3] ;  [4] « less
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  2. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  3. General Atomics, San Diego, CA (United States)
  4. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
Publication Date:
Report Number(s):
LA-UR-15-29483
Journal ID: ISSN 1070-664X
Grant/Contract Number:
AC52-06NA25396; AC52-07NA27344
Type:
Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 23; Journal Issue: 5; Journal ID: ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)
Research Org:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY
OSTI Identifier:
1408832
Alternate Identifier(s):
OSTI ID: 1252335