Magnetized ICF

MIFEDS was originally conceived to study neutron yield and ion-temperature enhancement due to magnetization in direct-drive ICF implosions 1. Magnetic field can reduce heat flow perpendicular to the field lines, which can improve fusion performance. Members of the Innovative Concepts Group also carried out the first magnetized hohlraum experiments on OMEGA. These experiments demonstrated the suppression of SRS (stimulated Raman scattering) and led to further experiments in collaboration with LANL, which showed enhanced gas fill heating 2. The group continues to study magnetized direct-drive and indirect-drive ICF and has developed a platform using dual MIFEDS gen 2.5 that allows the magnetization of 60-beam spherical implosions (see figure). Previous platforms used only 40 beams to allow space for the coils, therefore compromising the spherical symmetry. The group works in collaboration with scientists from LLNL to develop magnetized indirect-drive on the National Ignition Facility 3.
CAD drawing of magnetic field coils on the left an a photograph of magnetic filed coils on teh right.

CAD drawing from VISRAD showing the magnetic field coils, the targets, and all 60 laser beams (left) and a picture from the OMEGA target viewing system showing the setup in place before shot (right). The spherical target is just under 1 mm in diameter. The magnetic field at the target can reach 12 T.

1 P. Y. Chang et al., Phys. Rev. Lett. 107, 035006 (2011); M. Hohenberger et al., Phys. Plasmas 19, 056306 (2012).

2 D. S. Montgomery et al., Phys. Plasmas 22 (1), 010703 (2015); 22 (7), 0779901(E) (2015).

3 J. D. Moody et al., J. Fusion Energy 41, 7 (2022); J. D. Moody et al., Phys. Rev. Lett. 129, 195002 (2022); H. Sio et al., Phys. Plasmas 30, 072709 (2023).