Initial commissioning of the HV electrostatic generator for the Vivitron project

Soon after the complete assembly of the Vivitron as an electrostatic generator at the end of October 1990, initial commissioning began. Voltage tests were carried out at 7 bar SF6 from December 1990 to March 1991. An intermediate level of 17.6 MV was reached but with high parasitic currents from the rollers in the dead sections and with flashovers along the column and related damage to the insulating plates. A high level of humidity, which was diagnosed at a later stage, was the cause of those difficulties. In addition, major problems connected with the gas handling system stopped the tests for the rest of the year and up to the end of March 1992 when the generator was made ready for tests after carrying out repairs and cleaning which were completed by the end of January and then implementing some improvements and reassembly. A very encouraging level of 18.9 MV at 4 bar half pressure was reached in April, but this has not been reproduced since then due to various problems and damage from sparking. (orig.)