Fast Opening Switches Carrying Multimegampere Currents and Their Application to High Velocity Shock Waves in Xenon

Abstract

High-explosive-driven, magnetic-field generators can routinely produce currents on the order of hundreds of megamperes and magnetic fields of several megagauss. However, for applications such as shock tubes, these generators compress the magnetic flux much too slowly. Using a relatively small and inexpensive high-explosive-driven generator, we have developed an aluminum switch which is opened by the pressure produced by the high magnetic field. While approximately 10% of the magnetic flux leaks through the switch early, most of the current is switched from the aluminum to a half-atmosphere of xenon gas in a time less than 2/3 of a microsecond. The xenon is compressed approximately 3-fold, and this compressed sheath reaches a velocity of nearly 4 cm/μs. However, the sheath is less dense and less uniformly compressed than similar, slightly slower-moving sheaths driven by fast capacitor banks.