Evolution of the IGG concept at IGF from 2004 to 2007
  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 Several parts are outdated, but useful for an understanding of the phenomenon.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 Also outdated is the theoretical model developed in Ch. 1 on the "acceleration of Cooper pairs through the superconductor" as a possible basis for the anomalous emission.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. 
G. Modanese
physics.gen-ph