Accession Number:

ADA492446

Title:

Characterizing Coated Conductors with Variable Temperature Scanning Laser Microscopy (SLM)

Descriptive Note:

Final rept. 15 Dec 2004-14 Jun 2008

Corporate Author:

CALIFORNIA STATE UNIV LONG BEACH

Personal Author(s):

Report Date:

2008-09-03

Pagination or Media Count:

8.0

Abstract:

The grant supported research effort to understand factors limiting current-carrying capabilities in coated conductors CCs. Three new operating modes of scanning laser microscopy SLM were developed under this grant, and total of five SLM modes were utilized for the research. The research found that the increased local-current density current-crowding was the main cause for the dissipation and the limiting factor for the current-carrying capacity. It was found in striated CCs that the current-crowding was caused by scratches from sample-handling, localized damages during striation process, or current flow configuration due to specific striation patterns. The other aspect of the research was to understand superconducting dissipation from various YBCO-family films on bicrystal grain boundary GB junctions. The samples on 240 100-tilt GB showed that the dissipation appeared like hot-spots along GB. There was no significant difference in the size andor the pattern of hot-spots for different YBCO-family samples regardless of nanoparticle additions, doping, and multi-layering even though the current-carrying capability varied widely among the samples. The results implied that SLM features were determined by the GB angles not by the property of YBCO films when the dissipation began and the hot-spot appeared on GB.

Subject Categories:

  • Electrical and Electronic Equipment
  • Lasers and Masers

Distribution Statement:

APPROVED FOR PUBLIC RELEASE