Optical Diagnostics for the Pulsed Laser Deposition of YBa_2Cu_3O_(7-x) Superconducting Wires

摘要

One of the critical elements in the manufacture of long lengths of high temperature superconducting wires is the development of deposition diagnostics correlated with the quality of deposited material for process control. Fast imagery, emission spectroscopy, and time-of-flight spectroscopy of the very energetic plumes resulting from the pulsed laser deposition of YBa_2Cu_3O_(7-x) have been recorded for a wide range of deposition conditions at four military, DoE, and industrial facilities. Several optical signatures that are strongly correlated with the deposited critical currents have been identified with strong potential for process control. In addition, the partioning of energy among translation, electronic and ro-vibrational degrees of freedom as a function of laser fluence, chamber pressure, and position in the plume have been characterized.