Model experiment of magnetic field amplification in laser-produced plasmas via the Richtmyer-Meshkov instability
Model experiment of magnetic field amplification in laser-produced plasmas via the Richtmyer-Meshkov instability
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DOI：
10.1063/1.4944925
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发表时间：
2016-03
影响因子：
2.2
通讯作者：
Y. Kuramitsu;N. Ohnishi;Y. Sakawa;T. Morita;H. Tanji;T. Ide;K. Nishio;C. Gregory;J. Waugh;N. Booth;R. Heathcote;C. Murphy;G. Gregori;J. Smallcombe;C. Barton;A. Dizière;M. Koenig;N. Woolsey;Y. Matsumoto;A. Mizuta;T. Sugiyama;S. Matsukiyo;T. Moritaka;T. Sano;H. Takabe
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文献类型：
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作者：
Y. Kuramitsu;N. Ohnishi;Y. Sakawa;T. Morita;H. Tanji;T. Ide;K. Nishio;C. Gregory;J. Waugh;N. Booth;R. Heathcote;C. Murphy;G. Gregori;J. Smallcombe;C. Barton;A. Dizière;M. Koenig;N. Woolsey;Y. Matsumoto;A. Mizuta;T. Sugiyama;S. Matsukiyo;T. Moritaka;T. Sano;H. Takabe
利用高功率激光器进行了超新星遗迹（SNRs）中Richtmyer-Meshkov不稳定性（RMI）引起磁场放大（MFA）的模型实验。为了解释在信噪比中观测到的宇宙射线的非常快的加速，人们认为磁场必须从其背景水平放大几个数量级。在信噪比MFA的一个可能的机制是拉伸和混合的磁场通过RMI时，冲击波通过星际介质中的致密分子云。为了在实验室中模拟天体物理现象，RMI有三个必要的因素：冲击波，外部磁场和密度不均匀性。在外加磁场的作用下，用几束具有焦斑位移的激光束照射双层靶，激发出冲击波并穿过密度不均匀体。辐射流体动力学模拟结果表明，密度不均匀性受到冲击后，辐射介质界面会发生变化，从而导致更高的MFA。
A model experiment of magnetic field amplification (MFA) via the Richtmyer-Meshkov instability (RMI) in supernova remnants (SNRs) was performed using a high-power laser. In order to account for very-fast acceleration of cosmic rays observed in SNRs, it is considered that the magnetic field has to be amplified by orders of magnitude from its background level. A possible mechanism for the MFA in SNRs is stretching and mixing of the magnetic field via the RMI when shock waves pass through dense molecular clouds in interstellar media. In order to model the astrophysical phenomenon in laboratories, there are three necessary factors for the RMI to be operative: a shock wave, an external magnetic field, and density inhomogeneity. By irradiating a double-foil target with several laser beams with focal spot displacement under influence of an external magnetic field, shock waves were excited and passed through the density inhomogeneity. Radiative hydrodynamic simulations show that the RMI evolves as the density inhomogeneity is shocked, resulting in higher MFA.