and integration by parts.
\item Calculate $j_c(R,T=0K)$ for a wire of Sn with a radius of 1 mm at $T=0K$.
The critical current and penetration depth at $T=0K$ are
and integration by parts.
\item Calculate $j_c(R,T=0K)$ for a wire of Sn with a radius of 1 mm at $T=0K$.
The critical current and penetration depth at $T=0K$ are