skip to main content

Title: Time history prediction of direct-drive implosions on the Omega facility

We present in this article direct-drive experiments that were carried out on the Omega facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. Two different pulse shapes were tested in order to vary the implosion stability of the same target whose parameters, dimensions and composition, remained the same. The direct-drive configuration on the Omega facility allows the accurate time-resolved measurement of the scattered light. We show that, provided the laser coupling is well controlled, the implosion time history, assessed by the “bang-time” and the shell trajectory measurements, can be predicted. This conclusion is independent on the pulse shape. In contrast, we show that the pulse shape affects the implosion stability, assessed by comparing the target performances between prediction and measurement. For the 1-ns square pulse, the measured neutron number is about 80% of the prediction. For the 2-step 2-ns pulse, we test here that this ratio falls to about 20%.
Authors:
; ; ; ; ; ; ; ; ; ;  [1] ; ; ; ; ;  [2] ;  [3] ; ;  [4] ;  [5]
  1. CEA, DAM, DIF, F-91297 Arpajon (France)
  2. Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299 (United States)
  3. Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)
  4. Physics Department, University of Nevada, Reno, Nevada 89557 (United States)
  5. CEA, CVA, 21120 Is-sur-Tille (France)
Publication Date:
OSTI Identifier:
22493828
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 23; Journal Issue: 1; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; CONFIGURATION; COUPLING; DIRECT DRIVE LASER IMPLOSION; LASERS; NEUTRONS; OMEGA FACILITY; PULSE SHAPERS; PULSES; STABILITY; TIME RESOLUTION; VISIBLE RADIATION