Laser used to generate 700 Tesla magnetic field to guide laser fusion

A laser-driven capacitor–coil target was used to generate a strong 600-700 Tesla magnetic field. The strength of the magnetic field was measured on GEKKO-XII23,24, LULI200025, Shengguang-II26, and OMEGA-EP laser facilities. Experimental results revealed that a 600–700-T magnetic field was generated by using a tightly focused kilo-joule and nano-second infrared (λL = 1.053 μm) laser beam.

A diverging relativistic electron beam (REB) will be guided to a dense core. The gyroradius of a 1-MeV electron under the influence of a 1-kT (1000 tesla) magnetic field is 5 μm (microns), which is smaller than a typical core radius (20 μm – microns). A kilo-Tesla-level magnetic field is sufficient to guide the REB to the core.

Osaka University demonstrated that it was possible to efficiently heat plasma by focusing a relativistic electron beam (REB) accelerated by a high-intensity short-pulse laser with the application of a magnetic field of 600 tesla.

In this study, laser-to-core energy coupling reached a maximum of 8 percent. The laser-to-core energy coupling, i.e., the energy deposition rate of REB, depends on the density of the plasma to be heated. In calculation based on the ignition spark formation conditions, the energy deposition rate of REB obtained in this study is several times more than that obtained by the central ignition scheme. Thus, the researchers conclude that the magnetized fast isochoric heating is very efficient and useful for the development of laser fusion energy.

Nature Communications – Magnetized fast isochoric laser heating for efficient creation of ultra-high-energy-density states