A three-megavolt tandem accelerator for material, nuclear and life science research

The University of Jyväskylä is acquiring a 3 MV electrostatic tandem accelerator and related ion-optical components. The accelerator will be installed in the existing Accelerator Laboratory main target hall of the K130 cyclotron. The procurement includes 3 MV tandem accelerator, high-energy focusing optics and high-energy switching magnet. The existing H-, He- and cesium sputtering ion sources from the 1.7 MV Pelletron accelerator will be fitted to the new system. The low energy vacuum system and injector will be designed and built separately from this procurement. The beam lines after the switching magnet will also be moved from the 1.7 MV Pelletron accelerator. The area reserved for the new accelerator platform is 10x20 m, and the walls and ceiling used for radiation protection will be constructed from concrete blocks. The concrete floor can easily carry the weight of the system, but no cable channels can be chased to it. Approximate layouts for two example solutions will be provided with the tender documents. Description of the procurement object: A) Tandem accelerator, which terminal voltage is continuously variable at least between 250 kV and 3000 kV and accelerate with 1.25 MV terminal voltage more than 100 µA of injected negative hydrogen beam. Accelerator is suitable for accelerating both heavy and light ion beams. The accelerator has a gas stripper and a turbomolecular pump in the terminal to recirculate the stripper gas, no active control of stripper gas pressure is required. Vacuum system for the high-energy end, including at least one turbomolecular pump, isolation valve for the turbo, backing pump, valve to separate the two pumps, high vacuum gauge and power supplies are included. B) Electrostatic or magnetic ion optics components (quadruple doublet or triplet) after the accelerator which are able to focus heavy ions with low charge states. C) A double focusing dipole magnet after the focusing element which has minimum 7, but preferably 9, exit ports between -45° and +45° and magnetic rigidity over 80 MeV amu at 30 degree angle. All power supplies necessary are supplied. Preferentially the delivery and installation of the system would take place in early 2026. In the accelerator and related items, we especially value reliability, flexibility in different applications, high currents and high voltage stability and low voltage ripple. The procurement is mainly funded by means of FIRI funding from the Research Council of Finland. Contracting authority (JYU) may suspend the procurement procedure if the tenders exceed the budget available for the procurement. Prior references of comparable systems are required.