Generating magnetic fields stronger than 100 teslas using solenoids on COBRA

Abstract

The MagLIK [1] concept relies on magnetic field compression to limit electron losses to the liner wall and reach fusion parameters. To measure magnetic field compression, B-dot probes could be used at the beginning of the implosions. However, this probe will fail as the magnetic field becomes large when the liner compresses. Our goal is to create a 100T field on COBRA to check B-dot probe design integrity [2] as the magnetic field increases. We used two solenoids, oriented along the same axis, to produce this strong uniform magnetic field. By altering multiple parameters, such as winding density, turn radius, and distance between the coils, strong magnetic fields can be created with the pulsed power generator COBRA. With IMA 100ns current rise time we were able to produce fields larger than 50 teslas. Using visual simulation software, multiple simulations were run to determine ideal values for these parameters to obtain a magnetic field strength of 100 teslas between the coils. Once these parameters were found the coils were made and mounted on COBRA, the magnetic field strength between the coils was measured using a B-dot probe. Using laser interferometry and XUV measurements from plasma self-emission, we observed that plasma was not shorting the coil windings or the space between the two coils.