  IGG is the acronym for Impulse Gravity Generator, a device developed by E.
Podkletnov in 1997-2003 for generating high-voltage discharges through YBCO
electrodes. According to Podkletnov, an anomalous force beam is generated at
the discharge, which acts on distant material target of any composition with a
small repulsive force proportional to the target mass. An independent
replication of this device was started in 2004 at IGF, Germany (Institut fuer
Gravitationsforschung, Goede Foundation). The author was involved as
theoretical consultant and his first assignment was to study a possible
scaled-down version of the device. This required a thorough analysis of the
physical working principles of the apparatus, which was documented in several
internal reports from 2004 to 2009. The whole content of those from 2004 to
2007 is given here. Several parts are outdated, but useful for an understanding
of the phenomenon. In particular, the discharge mechanism was eventually found
to be different, namely a vacuum spark discharge instead of a low pressure
discharge with cascade gas ionization. Also outdated is the theoretical model
developed in Ch. 1 on the "acceleration of Cooper pairs through the
superconductor" as a possible basis for the anomalous emission. This naive
representation, however, is useful to show that such an acceleration does not
make sense in a superconductor like YBCO and that the correct picture is that
of (low-voltage) tunnelling of pairs through intrinsic Josephson junctions. The
present paper should therefore be regarded as an "historical summary", mainly
valuable as a reference for further developments.
