Reference beam dynamics layout for the SC CW heavy ion HELIAC at GSI

Abstract The standalone superconducting continuous wave heavy ion linac HELIAC (HElmholtz LInear ACcelerator) is a common project of GSI Helmholtz Centre for Heavy Ion Research and Helmholtz Institute Mainz (HIM) under key support of Goethe University Frankfurt (IAP) and in collaboration with National Research Nuclear University MEPhI and NRC “Kurchatov Institute” ITEP. In 2017 the first superconducting section of the linac has been successfully commissioned and extensively tested with beam at GSI. The measurements sufficiently present the capability of 216.816 MHz multi-gap Crossbar H-mode (CH) DTL-structures. An acceleration of heavy ions up to the design beam energy and beyond has been reached with the setup. The required acceleration gain of 0.5 MeV/u was achieved with heavy ion beams even above the design mass-to-charge ratio at maximum available beam intensity and full beam transmission. Recently the HELIAC beam dynamics concept foresees twelve superconducting CH-DTL cavities, assembled in four cryomodules. Each module is equipped with three accelerating CH structures, two superconducting solenoids for transverse beam focusing and a Spoke-type buncher for longitudinal beam matching. The linac is used to accelerate ions with a mass-to-charge ratio up to A ∕ z = 6 from the input energy of 1.4 MeV/u up to the smoothly variable output energy between 3.5 MeV/u and 7.3 MeV/u . The manuscript presents the reference beam dynamics layout of the entire HELIAC facility.