Laser-induced magnetic fields in ICF capsules

The advantages of inserting a magnetic field into an inertial-confinement-fusion (ICF) capsule before compressing it have been pointed out by many authors. A mechanism for generating such a field without the use of low-inductance electrical conductors attached to the capsule is presented. To use this mechanism to insert a magnetic field into an ICF capsule, the capsule must be redesigned. In our approach, a central conductor is added, a toroidal gap is cut in the outer wall and the DT fuel is frozen on the inner surface of the capsule. The capsule is dropped into the reaction chamber and struck first with the laser that generates the magnetic field. The magnetic field propagates into the interior of the capsule through the toroidal gap, and the main compression then closes the gap, crowbars the field, and compresses the fuel to ignition. Other uses of this mechanism include the generation of large magnetic fields in laboratory apparatus for the measurement of the effects of magnetic fields on material samples.