Ultra-high magnetic field generation driven by high-intensity laser implosion*

A strong magnetic field over 1 kT is used for various applications in the field of high-energy-density plasmas. So far, several laser-driven methods have been proposed and demonstrated by using micro-coil targets, flux compression, and self-generated magnetic fields. However, the Megatesla field has not been achieved in laboratories. In this research, we have demonstrated the microtube implosion, which may offer megatesla-class ultra-high magnetic field driven by a high-intensity laser. The experimental results show that the magnetic field of 10 kT, which is 50 times higher than the seed magnetic field, was generated by using the LFEX facility. This fact is supported by two proton measurements: proton radiography and angular distribution measurement of the accelerated protons. For the proton radiography, a comparison between the seed field and the amplified field shows a clear difference indicating the high magnetic field generation. In addition, the angular distribution measurement shows that the accelerated proton was deflected to 90 deg. from the incident laser axis. This result indicates that the generated magnetic field was at least 10 kT. The megatesla magnetic field generation will allow us to observe phenomena that cannot be achieved on a laboratory scale such as non-linear Zeeman splitting, Lorentz ionization, and Landau levels. We are sure that our results contribute to the high-energy-density plasma fields in the future.