Speaker
Ji Yan
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P1.2007.pdf
The progress of indirect-drive implosion experiments
On ShenGuang-III Proto-Type facility in china
Ji Yan1, Tian Xuan Huang1, Dong Guo Kang2, Feng Jun Ge2
1
Laser Fusion Research Center, Chinese Academy of Engineering Physics, Mianyang, China
2
Institute of Applied Physics and Computational Mathematics, Beijing,, China
A series experiments on SG-III Proto-type facility (8beams/8kJ/351nm) were performed
to study low to middle compression ratio implosion physics from 2007-2015. Meanwhile, some
experimental technique were improved for high accuracy implosion experiment study such as
Spherical-Bent-Crystal Radiography and KB radiography.
Firstly, the low compression ratio (CR~5) DD implosion experiments were preformed to
study the shock yield only implosion and examine the 1D hydrodynamic code (RDMG). The
experimental results proposed highly repetitive neutron yield. The two type capsules with
different scale-length produce 9.9x107(±9.7%) and 3.1x107(±6.5%) neutrons respectively.
Based on RDMG simulations, the ion-flux-limit-factor (IF) from 0.05 to 1 will influence the
neutron yield for shock yield process few times and had a little influence on inertial yield
process. In our shock yield only experiments, the YOC1D will reached at 80%~105% with the
IF equal to 1. Meanwhile, the NIF shock yield shots (Pape S.L, Phys.Rev.Lett 112,
225002(2014)) make 85% YOC1D using RDMG code with IF equal to 1.
Secondly, the low-middle compression ratio (CR~10) DT implosion experiments with
different ablator thickness, different gas fill and 220eV Radiation temperature were performed.
For thin shell implosion, nearly all neutrons comes from shock yield, 3 x109 DT neutrons were
collected and YOC1D is nearly 70%.on the other hand, for thick shell implosion, the inertial
yield accounts for the main in 1D simulation, 8 x108 DT neutron were collected and YOC1D is
less than 10% because of non-1D factor decreased implosion performance.
At last, two advanced diagnostic technique were developed for high accuracy implosion
experiments. The SBC Radiography was used for implosion stream line measurement. The
uncertainty of implosion velocity was around 9% and better than traditional slit radiography
which with the uncertainty of 15%; The KB radiography was used for hot-spot self-emission
because of high-spatial resolution (~3μm). The uncertainty of hot-spot shape was around ±2μm
and better than traditional pinhole-array radiography which with the uncertainty of around
±5μm.
