When a long current-carrying solenoid pierces a superconducting cylinder, the magnetic induction experienced by the superconductor (SC) is ideally zero anywhere apart from an edge with thickness of penetration depth  at the interior of the cylinder. Consequently, vortices are not expected to flow, or even form, in the SC. Nevertheless, the SC will experience a vector potential set by the solenoid, and, according to the London equation, supercurrent will flow in the SC cylinder. Thus, by driving the solenoid current, the critical-current of the SC can be measured in the absence of vortices and with no leads. This critical-current places an upper limit on the Ginzburg-Landau coherence length . We performed such a measurement using a NbTi SC solenoid and optimally doped LSCO single crystal cylinder. We found that nm. Future improvements in the experimental setup will allow us to place a tighter upper limit.