Magnetic fields are induced using high-energy electron currents produced by laser-plasma interactions. Guiding high-energy electron beams, insulating electron heat transport and so on are brought about by the circular motion of electrons around magnetic field lines in the laser-plasma interactions. Recently, strong magnetic fields up to 1 kT can be produced by the interaction of plasmas with power lasers. The behavior of laser-produced plasmas can be controlled by the strong magnetic fields. In this issue, we will show the present status and perspective of the research on the generation of strong magnetic field using power lasers and its applications.

View full abstract

With the increase in intensity and energy of high-power lasers, it became possible to generate kiloteslaclass magnetic fields that can be applied to high-energy-density physics experiments. The application of magnetic field broadens the interdisciplinary sciences covered by the high-energy-density-physics. In this article, we will introduce the generation of a strong magnetic field with a capacitor-coil and a sail targets driven by a high-power laser. Kilotesla magnetic field improves the quality of fast electron and ion beams produced by a high-power laser. We describe hydrodynamic instability caused by the anisotropy of thermal conduction in the external magnetic field, and the relativistic magnetic reconnection and particle acceleration associated with reconnection in high energy magnetized plasma, and finally, the challenge to 10 kT will be discussed.

View full abstract

Magnetic field compression by high power lasers is reviewed. In this paper, the basic design of magnetic compression, including requirements for the compression laser, generation of the initial magnetic field, model for the conductivity of the compressing metal shell, and diagnostics for compressed magnetic field are discussed.

View full abstract

In this paper, a generation of gigagauss magnetic field in ultra-intense laser plasma interactions is reviewed. Spontaneous magnetic field is created by the fast electron flow i) inside the dense plasma, accompanied with the return current to maintain the charge neutrality, and ii) on the plasma surface according to the motion of charged particles. Since these fields are created within a time scale of laser pulse ( < ps), newly developed methods to measure the transient magnetic fields have been introduced in recent experimental results.

View full abstract

We have demonstrated the enhancement of laser-to-core energy coupling with magnetized fast isochoric laser heating on the GEKKO-LFEX laser facility. The maximum coupling of 8% was achieved by application of external magnetic field, which was degraded gradually by increasing the heating laser energy with keeping both pulse duration and spot diameter unchanged. The obtained energy couplings are consistent with simple calculation models. The model predicts that 20-35% of energy coupling is achievable in the ignition-scale core with the moderate guiding field and heating laser intensity.

View full abstract

Magnetic reconnection is a fundamental plasma process that breaks and rearranges magnetic field lines, and converts magnetic field energy into plasma energy. Magnetic reconnection is important in the dynamics of magnetized plasmas in space physics, astrophysics, and laboratory experiments. In this paper, we show recent progress of the experimental research on magnetic reconnection using powerlaser and pulse-power systems.

View full abstract

Laser fusion rocket is a thrust system in which a propellant is ionized by a plasma from inertial confinement fusion (ICF), and the lasers are driven by an output energy from ICF. The laser fusion rocket generates large thrust and high specific impulse simultaneously and it would be one of the candidates for manned interplanetary missions, as reported in the concept of ICF rocket (VISTA), which has been first proposed in 1983 and summarized in 2003. Though this system uses a magnetic nozzle to control and extract a propellant plasma, it is unclear how the magnetic nozzle works in such an explosively expanding plasma. In this paper, we introduce the numerical research on this thrust system, and experimental investigations of thrust generation, ion extraction, and plasma diagnostics.

View full abstract