I have been doing some readings on superconductivity and have come across the London penetration depth. I somewhat understand how it comes into play with the London equation and Ampère's law.
Right now, I am having a hard time finding out how one would, if one is given a material that is said to be a superconductor and knowing only the critical temperature, be able to determine the $\lambda_L$ of this material.
I know that it is possible to use μSR, but how exactly would one go about doing that? Also, is that the only experimental method if one does not know anything else about the material?