A laser quenched superconducting switch for pulsed power applications

We have prepared micron thick films of NSN and NbCN by rf reactive sputtering. Sputtering conditions were varied in order to maximize the critical current density and the normal state resistivity. Both of these quantities are important for a normally closed switch in parallel with a load. The product of these two quantities is a figure of merit used to compare films prepared under different conditions. By varying substrate temperature, argon pressure and adding small amounts of oxygen to the reactive gas mixture, we have achieved a value of 900 V/cm. In addition we have fabricated some of these films into a laser activated switch which opens and recovers in times on the order of nanoseconds.