On the possibility of neutron spectroscopy of microwave currents in thin   superconducting films
  The inelastic magnetic scattering of neutrons from thin superconducting films irradiated with microwave radiations, is analyzed. This process is due to the interaction of the magnetic field generated by the neutron, with the oscillating current induced by the electromagnetic field penetrated into the film. In the Born approximation, the neutron energy can both increase and decrease by the energy quantum of the field. The scattering cross section, which increases with decreasing the field frequency, is derived, and its numerical calculations are carried out. Measurements of this cross section give directly the frequency-dependent supercurrents in the films. 
Alexander Agafonov
cond-mat.supr-con