  The detection of apparent anomalous forces in the vicinity of high-Tc
superconductors under non equilibrium conditions has stimulated an experimental
research in which the operating parameters of the experiment have been pushed
to values higher than those employed in previous attempts. The results confirm
the existence of an unexpected physical interaction. An apparatus has been
constructed and tested in which the superconductor is subjected to peak
currents in excess of 10^4 A, surface potentials in excess of 1 MV, trapped
magnetic field up to 1 T, and temperature down to 40 K. In order to produce the
required currents a high voltage discharge technique has been employed.
Discharges originating from a superconducting ceramic electrode are accompanied
by the emission of radiation which propagates in a focused beam without
noticeable attenuation through different materials and exerts a short repulsive
force on small movable objects along the propagation axis. Within the
measurement error (5 to 7 %) the impulse is proportional to the mass of the
objects and independent on their composition. It therefore resembles a
gravitational impulse. The observed phenomenon appears to be absolutely new and
unprecedented in the literature. It cannot be understood in the framework of
general relativity. A theory is proposed which combines a quantum gravity
approach with anomalous vacuum fluctuations.
