Origin of the B-Dot Jump Observed in Precision Liner Experiments
LOS ALAMOS NATIONAL LAB NM
Pagination or Media Count:
In the liner-ejecta experiments carried out at the Los Alamos pulsed power facility Pegasus II, a solid liner was magnetically imploded to impact on a target cylinder to produce the shock-induced ejecta. As a result of improved time resolution for the B-dot dBdt probes fielded last fall, we began to notice a sharp jump in the B-dot curve occurring at a time very close to the expected liner-target collision time. This jump was also found in the time derivative of the calculated current dIdt obtained from code simulation. We have shown that the jump is indeed caused by the collision as a sudden change of the liner velocity would induce a sudden jump in the time derivative of the inductance. We have derived a general formula for calculating the jump in didt and verified that the result computed from it is in good agreement with the code simulation. Useful diagnostic applications of the B-dot jump are discussed.
- Electricity and Magnetism