Electronics Weekly Electronics Design & Components Tech News
Presenting data to the US Department of Energy, the firm said it had made lengths of 2G wire with performance high enough to convince it to move towards mass production.
“First we’ll finalise conversion of our current 2G development facility into a pre-pilot production line by the spring of 2005 to produce and ship more than 10,000m of 2G wire during the fiscal year ending March 2006,” said company president David Paratore.
“Second, we plan to scale-up to full pilot production in order to achieve an annual production capacity of approximately 300,000m of 2G HTS wire by the end of calendar 2007.”
AMSC already makes commercial 1G wire by rolling and drawing silver alloy tapes containing threads of ‘BSCCO’ ((Bi1.8Pb0.3)Sr2Ca2Cu 3O10) HTS. This is available in lengths of over 1km, carrying up to 350A per centimetre of width.
2G superconductor wire, invented in Japan in the early 1990s, is made from a thin film of epitaxially-grown YBa2Cu3O7, or ‘YBCO’, HTS on a thin tape substrate. In between is a buffer layer which causes the crystal axis in individual YBCO grains to align with the axis of other grains, virtually removing the detrimental effects of grain boundaries.
Work on this crucial buffer layer has progressed and, together with other developments, the firm has produced lengths of 10mm wide 2G wire over 30m long, and tested them at between 160 and 185A, said AMSC.
Second-generation HTS wire has the potential to conduct more current than 1G wire, and can operate in higher magnetic fields.
“YBCO is much harder to make,” Dr Philip Sargent of Cambridge’s Diboride Conductors told Electronics Weekly, “but it is likely to be cheaper in large volume.”
Sargent is developing MgB2 medium-temperature superconductors which are easier to work with than BSCCO and YBCO types, but have to be cooled more.
