Institute of Laser Engineering, Osaka University, 02-06 Yamada-Oka, Suita, Osaka, 565-0871, Japan.
Department of Mechanical Systems Engineering, Hiroshima University, Higashi-Hiroshima, Hiroshima, 739-8527, Japan.
Nat Commun. 2018 Sep 26;9(1):3937. doi: 10.1038/s41467-018-06173-6.
Fast isochoric heating of a pre-compressed plasma core with a high-intensity short-pulse laser is an attractive and alternative approach to create ultra-high-energy-density states like those found in inertial confinement fusion (ICF) ignition sparks. Laser-produced relativistic electron beam (REB) deposits a part of kinetic energy in the core, and then the heated region becomes the hot spark to trigger the ignition. However, due to the inherent large angular spread of the produced REB, only a small portion of the REB collides with the core. Here, we demonstrate a factor-of-two enhancement of laser-to-core energy coupling with the magnetized fast isochoric heating. The method employs a magnetic field of hundreds of Tesla that is applied to the transport region from the REB generation zone to the core which results in guiding the REB along the magnetic field lines to the core. This scheme may provide more efficient energy coupling compared to the conventional ICF scheme.
利用高强度短脉冲激光对预压缩等离子体芯体进行快速等容加热是一种很有吸引力的替代方法,可以用来产生类似于惯性约束聚变(ICF)点火火花的超高能量密度状态。激光产生的相对论电子束(REB)将部分动能沉积在芯体中,然后加热区域成为热点以触发点火。然而,由于产生的 REB 固有较大的角向扩展,只有一小部分 REB 与芯体碰撞。在这里,我们展示了通过磁控快速等容加热将激光能量耦合到芯体的效率提高了一倍。该方法采用数百特斯拉的磁场,施加于从 REB 产生区到芯体的传输区,从而使 REB 沿着磁场线引导至芯体。与传统 ICF 方案相比,该方案可能提供更有效的能量耦合。