High repetition-rate neutron generation by several-mJ, 35 fs pulses interacting with free-flowing D2O
High repetition-rate neutron generation by several-mJ, 35 fs pulses interacting with free-flowing D2O
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DOI：
10.1063/1.4963819
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发表时间：
2016-10-03
影响因子：
4
通讯作者：
Thomas, A. G. R.
中科院分区：
文献类型：
--
作者：
Hah, J.;Petrov, G. M.;Thomas, A. G. R.
使用来自高重复率 (1/2 kHz)、超短 (35 fs) 脉冲激光的数 mJ 能量脉冲与直径为 10 μm 的自由流动重水 (D2O) 流相互作用，我们展示了 10(5)/s 的 2.45MeV 中子通量。在高强度（10 19 W/cm(2) 量级）下工作时，激光脉冲能量被前等离子体有效吸收，产生高能氘核。它们与大块靶材和靶材周围大量低密度 D2O 蒸气中的氘核碰撞，通过 d(d,n)(3) He 反应产生中子。通过校准的中子气泡探测器测量的中子通量随着激光脉冲能量从 6 mJ 增加到 12 mJ 而增加。测量的通量与二维粒子内模拟结果之间的定量比较表明，激光特性的中子通量与实验相似。模拟显示有两组氘核。向前移动的氘核在 D2O 流中产生氘-氘聚变反应并充当中子点源，而向后移动的氘核则通过低密度 D2O 蒸汽填充室传播并产生体积中子源。由 AIP 出版社出版。
Using several-mJ energy pulses from a high-repetition rate (1/2 kHz), ultrashort (35 fs) pulsed laser interacting with a similar to 10 mu m diameter stream of free-flowing heavy water (D2O), we demonstrate a 2.45MeV neutron flux of 10(5)/s. Operating at high intensity (of order 10 19 W/cm(2)), laser pulse energy is efficiently absorbed in the pre-plasma, generating energetic deuterons. These collide with deuterium nuclei in both the bulk target and the large volume of low density D2O vapor surrounding the target to generate neutrons through d(d,n)(3) He reactions. The neutron flux, as measured by a calibrated neutron bubble detector, increases as the laser pulse energy is increased from 6 mJ to 12 mJ. A quantitative comparison between the measured flux and the results derived from 2D-particle-in-cell simulations shows comparable neutron fluxes for laser characteristics similar to the experiment. The simulations reveal that there are two groups of deuterons. Forward moving deuterons generate deuterium-deuterium fusion reactions in the D2O stream and act as a point source of neutrons, while backward moving deuterons propagate through the low-density D2O vapor filled chamber and yield a volumetric source of neutrons. Published by AIP Publishing.