At temperatures near absolute zero, the critical field Bc for vanadium, a type-I superconductor, approaches 0.142 tesla. The normal phase of vanadium has a magnetic susceptibility close to zero. Consider a long, thin, solid vanadium cylinder with its axis parallel to an external magnetic field B 0 in the +x direction. At points far from the ends of the cylinder, by symmetry, all the magnetic vectors are parallel to the x axis.