Compressing magnetic fields with high-energy lasers
Compressing magnetic fields with high-energy lasers
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DOI：
10.1063/1.3416557
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发表时间：
2010-05-01
影响因子：
2.2
通讯作者：
Seguin, F. H.
中科院分区：
文献类型：
--
作者：
Knauer, J. P.;Gotchev, O. V.;Seguin, F. H.
首次报道了激光驱动磁场压缩产生数十兆高斯磁场。在圆柱形靶的内爆期间形成的冲击波捕获初始（种子）磁场，该初始磁场经由磁通量守恒而被放大。这样大的磁场预计会磁化热的中心等离子体中的电子，导致回旋频率超过碰撞频率。Omega激光装置[T. R. Boehly，Opt. Commun. 133，495（1997）]用于内爆填充有氘气并用来自磁脉冲发生器的外场（> 50 kG）接种的圆柱形CH靶。该种子场被内爆壳层捕获并迅速压缩，从而使电阻通量扩散的影响最小化。压缩场探测通过质子偏转使用14.7 MeV的质子从D + He-3聚变反应发出的内爆玻璃微球。测量到内爆核心的线平均磁场在30到40 MG之间。用一维流体动力学程序LILAC的磁流体动力学版本[J.Delettrez，Phys.Rev.A36，3926（1987）; N. W. Jang，Bull. Am. 51，144（2006）]和粒子传播代码GEANT 4 [S. Agostinelli，Nucl. Instrum. Methods Phys.Res.A506，250（2003）]。(C)2010年美国物理学会。[doi 10.1063/1.3416557]
Laser-driven magnetic-field compression producing a magnetic field of tens of megaGauss is reported for the first time. A shock wave formed during the implosion of a cylindrical target traps an initial (seed) magnetic field that is amplified via conservation of magnetic flux. Such large fields are expected to magnetize the electrons in the hot, central plasma, leading to a cyclotron frequency exceeding the collision frequency. The Omega Laser Facility [T. R. Boehly , Opt. Commun. 133, 495 (1997)] was used to implode cylindrical CH targets filled with deuterium gas and seeded with an external field (>50 kG) from a magnetic pulse generator. This seed field is trapped and rapidly compressed by the imploding shell, minimizing the effect of resistive flux diffusion. The compressed field was probed via proton deflectrometry using 14.7 MeV protons from the D+He-3 fusion reaction emitted by an imploding glass microballoon. Line-averaged magnetic fields of the imploded core were measured to between 30 and 40 MG. Experimental data were analyzed with both a magnetohydrodynamic version of the one-dimensional hydrocode LILAC [J. Delettrez , Phys. Rev. A 36, 3926 (1987); N. W. Jang , Bull. Am. Phys. Soc. 51, 144 (2006)] and the particle propagation code GEANT4 [S. Agostinelli , Nucl. Instrum. Methods Phys. Res. A 506, 250 (2003)]. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3416557]