US patent (13/155,508) titled "Enhancing Critical Current Density
of Cuprate Superconductors" discloses a method for enhancing the critical current density
in superconductors by restricting the movement of Abrikosov (A) vortices, Josephson (J) vortices, or Abrikosov-Josephson (A-J) vortices using the half integer vortices associated with the d-wave symmetry present in the grain boundary.
In comparison to low-temperature superconducting wire, which is already being used for MRI, NMR, linear motorcars and more, high-temperature superconducting wire has a higher critical current density
(size of electric current), lowers costs by using liquid nitrogen for cooling, and reduces susceptibility to the effects of external magnetic fields, so the development of high-temperature superconducting wire is currently being promoted.
Sediqeh Dadras, the faculty member of Alzahra University in Tehran, et al increased the critical current density
of high temperature superconductor YBCO up to 10 times by using CNT.
One major obstacle to this is the degradation of the critical current density
Other topics include thermal transients in MgB2 conductors, theories of peak effect and anomalous Hall effect, doping effects on the superconducting properties of bulk and PIT MgB2, optimizing critical current density
, and microwave response of ceramic samples.
These models allow us to predict the current path through a geometrically complex and non-homogenous system, and to determine what percentage of the heart has reached the critical current density
level for defibrillation," said Lindeman.
Removing the top nickel substrate restores the critical current density
to its original value.
At present, the maximum amount of current per cross-sectional area, or critical current density
, of BSCCO--roughly 70,000 amperes per square centimeter (A/[cm.
a leading developer of superconducting microelectronics (SME) technology, recently achieved a major milestone when it successfully tested fabricated integrated circuits featuring a critical current density
of 20 kiloamps per square centimeter (kA/cm2).
Buckyball compounds may also surpass their competitors in terms of critical current density
, or the amount of current the superconductor can carry before losing zero resistance.
Four months ago, when two independent research groups reported the discovery of billions of spiral defects in superconducting thin films, both teams suggested that putting these defects, called screw dislocations, into wires might boost their current-carrying capacity, or critical current density
, to that of thin films (SN: 4/6/91, p.
These and other devices will only work, however, if improvements can be made in such factors as critical current density
and film stability.