Fusion Generated Fast Particles by Laser Impact on Ultra-Dense Deuterium: Rapid Variation with Laser Intensity
Fusion Generated Fast Particles by Laser Impact on Ultra-Dense Deuterium: Rapid Variation with Laser Intensity
复制标题
通过激光撞击超密氘聚变产生快速粒子：随激光强度的快速变化
DOI：
10.1007/s10894-011-9468-2
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
L. Holmlid
中科院分区：
文献类型：
--
作者：
P. U. Andersson;L. Holmlid
利用纳秒脉冲激光与超高密度氘相互作用研究了核聚变D+D过程。这种材料的密度为1029 cm − 3，如之前的几篇出版物所示。激光功率<2 W（0.2 J脉冲），激光强度<1014 W cm-2，束腰宽度为5-10 μm。使用通过具有塑料衰减器的飞行时间能量分析的颗粒检测。粒子流中的金属箔到检测器去除慢离子，并使其能够转换和计数能量远高于1 MeV的粒子。测量了D+D聚变产生的MeV粒子信号随激光功率的变化。在相对较弱的激光-发射器相互作用下，来自激光焦点的粒子信号随着激光功率的平方而变化。这表明库仑爆炸释放的两个快氘的超密度氘发生碰撞。在具有较强的激光-发射器相互作用的实验期间，信号大约随着激光功率的六次方而变化，指示等离子体过程。在所用的最大强度下，每个激光脉冲至少产生2 × 106个粒子。我们的研究结果表明，即使在融合在1 J的激光脉冲能量与相同的聚焦，在超致密氘点火条件的理论结果近似一致。然而，在高温下的辐射损失将需要更高的激光能量才能达到收支平衡。
Nuclear fusion D+D processes are studied by nanosecond pulsed laser interaction with ultra-dense deuterium. This material has a density of 1029cm−3as shown in several previous publications. Laser power is <2 W (0.2 J pulses) and laser intensity is <1014W cm−2in the 5–10 μm wide beam waist. Particle detection by time-of-flight energy analysis with plastic scintillators is used. Metal foils in the particle flux to the detector remove slow ions, and make it possible to convert and count particles with energy well above 1 MeV. The variation of the signal of MeV particles from D+D fusion is measured as a function of laser power. At relatively weak laser-emitter interaction, the particle signal from the laser focus varies as the square of the laser power. This indicates collisions in the ultra-dense deuterium of two fast deuterons released by Coulomb explosions. During experiments with stronger laser-emitter interaction, the signal varies approximately as the sixth power of the laser power, indicating a plasma process. At least 2 × 106particles are created by each laser pulse at the maximum intensity used. Our results indicate break-even in fusion at a laser pulse energy of 1 J with the same focusing, in approximate agreement with theoretical results for ignition conditions in ultra-dense deuterium. Radiation loss at high temperature will however require higher laser energy at break-even.
影响因子：
64.8
作者：
Kodama, R;Norreys, PA;Zepf, M
通讯作者：
Zepf, M