Design of a Superconducting Magnetic Levitation System

摘要

A preliminary project for the realisation of the kilogram using the "superconducting magnetic levitation method" has been started at MIKES. The work will be carried out in cooperation with VNIIM, Russia. In the levitation method there are still problems, which have to be solved before the final goal, a relative uncertainty of 10~(-8) for the kilogram, can be reached. The main problem at present is energy losses due the incompleteness of the Meissner effect. These losses will be generated if the magnetic flux intrudes into a superconductor. Energy losses can jeopardise the experiment. To measure these losses we are developing a cryogenic calorimeter. The resolution of the device will be about 1 nW. We have also started to optimise the geometry of the levitated body and the coil, which produces the levitating magnetic field in order to minimise the effect of the energy losses.