Water Jet Guided Laser Cutting of High Temperature Superconductors

In order to reduce their hysteresis losses, water jet guided laser cutting is applied to process 55m thin high temperature superconducting tapes. A 100W fiber coupled 532nm pulsed diode pumped solid state laser is employed in conjunction with a water jet guided cutting system to minimize the burr height and the heat affected zone along the cut kerf. To optimize the laser process a Design of Experiment approach is chosen with the input parameters being laser power, laser repetition rate, tape velocity and water pressure, respectively. To evaluate the improvement of the laser cutting process on the performance of the high temperature superconducting tapes in the AC modus, hysteresis losses of untreated and laser cut superconducting tapes are compared. As a result, we achieve burr free and clean cut kerfs that lead to critical current losses of 16% and hysteresis losses on the order of 48% to 70%, respectively.