Review of Poher experiment on fields produced by electric discharges in   a superconductor
  High current through cold YBaCuO produced effects on the mounting and on remote piezoelectric detectors. The effects were not observed with warm YBaCuO or other cold or warm materials. Two hypotheses are evaluated for the direct mechanical forces: a hypothetical vacuum field, and a model in which boil off of liquid nitrogen acts as a thruster. Data from the remote detector are compared with data from Podkletnov. Properties of a field required to explain data with the remote detectors are described. 
R.A. Lewis
physics.gen-ph