Speakers
Description
The SPES project is based at INFN LNL and covers basic research in nuclear physics and astrophysics, radionuclide production, materials science research, nuclear technology, and medicine. ALPI is a linear accelerator, equipped with superconducting quarter-wave resonators (QWRs) and it will be used also to accelerates SPES radioactive beams. The ALPI enhancement is critical with respect to the SPES project facilities. The ALPI upgrade is based on the implementation of two additional cryostats in the high-β section. The technology is well established, and it also confirmed from the fact that cavities installed in 1999 on accelerator were recently re-measured and they demonstrate the same performance after 22 years of activity on accelerator. The production technology of Nb/Cu QWRs should be adjusted for high-β cavities for increasing the performance of resonators and production 8 cavities for the ALPI upgrade. In the framework of the upgrade two vacuum systems (for biased sputtering and for cryogenic measurements) were refurbished. Optimal parameters of the biased sputtering processes of copper QWR cavities and plates were defined. The process of mechanical, chemical, and electrochemical preparation, sputtering and cryogenic measurement of the high-β Nb/Cu QWR cavities was adjusted. The best result of cryogenic measurements of produced QWR is Q0 = 2.0 · 109; Q7W = 2,76 · 108 ; Eacc (at 7W) = 5,54 MV/m. Currently, the production of the Nb/Cu QWR cavities and plates is ongoing.
