Implosion and heating experiments of fast ignition targets by Gekko-XII and LFEX lasers
Implosion and heating experiments of fast ignition targets by Gekko-XII and LFEX lasers
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Gekko-XII 和 LFEX 激光器快速点火目标的内爆和加热实验
DOI：
10.1051/epjconf/20135901008
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发表时间：
2013
影响因子：
--
通讯作者：
et at.
中科院分区：
文献类型：
--
作者：
H. Shiraga;et at.
FIREX-1项目的目标是通过快速点火方案将燃料加热到5 keV，该项目自2003年以来一直在进行，包括LFEX激光器的建造和调谐以及综合实验。自2009年以来，使用Gekko-XII和LFEX激光器进行了快点火靶的内爆和加热实验。用0.53 μm的Gekko-XII内爆氘代聚苯乙烯壳靶，并将1.053 μm的LFEX激光束通过连接到壳上的金锥注入，以产生热电子来加热内爆的燃料等离子体。LFEX光束的脉冲对比度显著提高。此外，还开发了各种等离子体诊断仪器，以适应强烈的硬X射线（γ射线）和电磁脉冲的恶劣环境，这是由于靶上的强烈LFEX束。在中子探测器的飞行时间记录中，发现DD中子信号周围的大背景信号由（γ，n）反应中子和散射γ射线组成。通过仔细消除这种背景，证实了中子产额的增加。中子增强高达3.5 × 107。假设温度均匀上升，估计加热效率为10-20%。
The FIREX-1 project, the goal of which is to demonstrate fuel heating up to 5 keV by fast ignition scheme, has been carried out since 2003 including construction and tuning of LFEX laser and integrated experiments. Implosion and heating experiment of Fast Ignition targets have been performed since 2009 with Gekko-XII and LFEX lasers. A deuterated polystyrene shell target was imploded with the 0.53- μm Gekko-XII, and the 1.053- μm beam of the LFEX laser was injected through a gold cone attached to the shell to generate hot electrons to heat the imploded fuel plasma. Pulse contrast ratio of the LFEX beam was significantly improved. Also a variety of plasma diagnostic instruments were developed to be compatible with harsh environment of intense hard x-rays (γ rays) and electromagnetic pulses due to the intense LFEX beam on the target. Large background signals around the DD neutron signal in time-of-flight record of neutron detector were found to consist of neutrons via (γ,n) reactions and scattered gamma rays. Enhanced neutron yield was confirmed by carefully eliminating such backgrounds. Neutron enhancement up to 3.5 × 107was observed. Heating efficiency was estimated to be 10–20% assuming a uniform temperature rise model.