The novel HVEE 5 MV TandetronTM

Recently, HVEE has extended the voltage range for its TandetronTM accelerators from 3 MV terminal voltage to 5 MV terminal voltage with the development of an entirely new coaxial TandetronTM. The new 5 MV system is presently in the final test phase and will shortly be installed at the Universidad Autonoma de Madrid (Spain) as part of their new IBA facility. The all-solid-state power supply (parallel-fed Cockroft-Walton type) is constructed around the high-energy accelerator tubes, thereby avoiding the T-shaped tank that was so far characteristic for the HVEE TandetronsTM. During the design of the system special emphasis has been put to minimize the electrical field strength in the complete structure. Using three-dimensional electrostatic field simulations, we were able to identify possible hot spots and to reduce the maximum field strength to 80% compared to that of older designs. This reduction in field strength guarantees more reliable operation at or even above the guaranteed terminal voltage of 5 MV. The electrical power for beam transport is generated by a 10 kW version of a recently in-house developed range of all-solid-state drivers with output powers of up to 25 kW. Apart from IBA applications like heavy element ERDA and NRA, the system is very well suited for other applications like positron emission tomography, deep implants in semiconductors as well as accelerator mass spectrometry of various elements, including 36Cl and 41Ca