Low-beta Superconducting Radio Frequency (SRF) is presently one of the main fields of linear accelerators technology, and it is used in many projects worldwide for acceleration of protons and heavy ions up to several MW of beams power. Applications include fundamental and applied research in physics, material sciences, biology, chemistry, medicine, energy production, waste transmutation, cancer therapy, medical diagnostics and many others. The low-beta SRF technology is in a continuous expansion, and recently became the first option for heavy ion linacs: FRIB at MSU is presently the most important example worldwide.
My main field of activity is Accelerator Physics - Linac technology, in particular superconducting low- and medium-beta resonators. I moved from nuclear physics to accelerator physics in 1987 during my stay as Postdoctoral Fellow at the Weizmann Institute (Israel), where I joined a pioneering and exciting work on low-beta superconducting linacs for heavy ions. At that time we designed and prototyped the first full Niobium, double wall Quarter-Wave Resonator (QWR), precursor of the FRIB QWRs and many other ones in several laboratories worldwide. In 1988 I moved to INFN (Istituto Nazionale di Fisica Nucleare), in Italy, joining from its start the innovative ALPI-PIAVE low-beta superconducting linac project at the National Laboratories of Legnaro, near Padua, where for the first time Bulk Nb double wall QWRs, Cu/Nb sputtered QWRs and superconducting RFQs were used in a linac. I worked in the design, construction and commissioning of low-beta QWRs with various optimum velocities, and of related cryomodules and pulsing systems. We extended high pressure water rinsing (HPR) as final treatment to low-beta cavities (at that time used only in elliptical cavities), reaching high Q and reduced field emission; we developed and introduced in superconducting QWRs special mechanical dampers, now utilized in many QWRs worldwide, which limit the resonators detuning caused by mechanical vibrations; we studied beam steering caused by QWRs, which was largely underestimated or neglected until 2001, and developed an analytical method to calculate and correct it. At Legnaro I worked also in intermediate-beta superconducting cavities (Half-Wave, Reentrant) and beam dynamics for high current proton and heavy ion linacs, for future Radioactive Ion Beam (RIB) Facilities and Accelerator Driven Systems (ADS) for nuclear waste transmutation.
I have worked in the development and construction of the superconducting cavities of the ISAC-II facility at TRIUMF (Vancouver, Canada); in mechanical damping of the superconducting low-beta cavities of the superconducting linac at Argonne National Lab. (Chicago, IL, USA); in the design study and technological development for the European radioactive beam facility project EURISOL with CEA Saclay, IPN Orsay and SOREQ NRC (Israel), and in other projects. I am presently working in the IFMIF-EVEDA project for the construction of a 100 mA deuteron linac prototype, a large Europe-Japan collaboration involving several contributing institutions.
I started collaborating in superconducting linac development at Michigan State University since 2001, when the ReA3 linac conceptual design based on QWRs started taking form. I joined the FRIB project in spring 2011, leading the Superconducting RF department for one year; in that period the ReA3, beta=0.085 QWRs were brought to full performance and the design of the FRIB superconducting resonators was finalized. I am presently Accelerator System Division Senior Advisor, working especially in superconducting resonators and cryomodule development for FRIB, ReA and in development of high gradient, low-beta resonators for future accelerators.
Selected PublicationsA. Facco and V. Zvyagintsev, “Beam steering in superconducting quarter-wave resonators: An analytical approach”, Phys. Rev. ST Accel. Beams 14, 071001 (2011)
A. Facco, R. Paparella, D. Berkovits and I. Yamane, “Splitting of high power, cw proton beams”, Phys. Rev. ST Accel. Beams 10, 091001 (2007)
A. Facco et al., “Low- and intermediate-beta, 352 MHz superconducting half-wave resonators for high power hadron acceleration”, Phys. Rev. ST Accel. Beams 9, 110101 (2006)
A. Facco et al., “On-line performance of the mechanically damped superconducting low beta resonators”, proc. of the European Particle Accelerator Conf., Stockholm , Sweden, 1998.
A. Facco, “Mechanical mode damping in superconducting low-beta resonators”, Particle Accelerators, Vol. 61, 1998, pp. 265-278.