Abstract : The analysis of the results of the preliminary experimental program has been pursued with emphasis on the visible radiation from vacuum gaps. The results are consistent with both thermal and transition radiation phenomena. The 320 kv system has been assembled and the components necessary for the pilot experiment checked out, viz. the vacuum chamber, the bakeout system, the high voltage generator and control unit, the feedthrough bushing and the electrodes support and adjustment mechanism. Fabrication has been initiated on the other components such as the magnetic field coils, power supply for same and the energy storage system. Much useful information and technology was gained from the solving of the problems encountered. The design of the pilot two-level partial factorial experiment was slightly modified to lessen the confustion of bakeout with other interactions. As many as possible of the prebreakdown phenomena will be monitored continuously in order to describe completely the vacuum gap and the electrode surfaces during this experiment. (Author)