IFIN-HH, Magurele-Bucharest
The Bucharest FN Tandem Accelerator was put in operation in 1973 and upgraded a first time in 1983 to 9 MV. In the period 2006-2009 a second program of the tandem upgrade was performed aiming to transform this accelerator in a modern and versatile facility for atomic and nuclear physics studies as well as for different applications using accelerated ion beams. The upgrade was achieved by replacing the main components of the tandem by new ones and by adding new components. The old HVEC belt of the Van de Graaff generator was replaced by a "Pelletron" system, the old inclined field stainless steel electrodes accelerator tubes were replaced by titanium spiral field tubes, the old HICONEX 834 sputter negative ion source was replaced by a new SNICS II sputter source and all old electronic equipment including RMN and Hall probe gauss meters as well as low voltage and high voltage power supplies for the magnets, lenses and ion sources were replaced by new ones. The new equipment added to the tandem consists of a helium negative ion source, a new injector based on a multi-cathode ion source 40 MC-SNICS II for AMS applications, a new GVM, a new pulsing system in the millisecond range and a new chopper and bunching system for pulsing the ion beam in the nanosecond range. Now the tandem is currently operated in very stable conditions up to 9 MV on a basis of about 4000 hours/year accelerating a broad range of ion species.
