FRIB, East Lansing, USA
The radio-frequency quadrupole (RFQ) at the Facility for Rare Isotope Beams (FRIB) is a 4-vane type cavity designed to accelerate heavy ion beams with charge states Q/A between 1/7 and 1/3 from 12 keV/u to 0.5 MeV/u. The RFQ was assembled in the FRIB tunnel in November 2016. Bead-pull measurements and tuning were performed with low RF power. The RFQ has been conditioned to 59 kW in August 2017, which is sufficient to accelerate the Key Performance Parameter (KPP) beams, Argon and Krypton. The RFQ has been successful-ly commissioned with KPP beams in CW regime in Octo-ber 2017. 40Ar9+ and 86Kr17+ beams were accelerated by the FRIB RFQ in the CW regime to the designed energy of 0.5 MeV/u. With the multi-harmonic buncher operation-al, the FRIB RFQ commissioning has been completed with bunched beam in February 2018. The beam trans-mission efficiency through the RFQ was in good agree-ment with PARMTEQ simulation results. The detailed results from the FRIB RFQ tuning, high power condition-ing and beam commissioning will be presented in this paper.
FRIB, East Lansing, USA
NSCL, East Lansing, Michigan, USA
This paper presents recent developments of accelerator physics related topics for the Facility for Rare Isotope Beams (FRIB) being built at Michigan State University. While extensive beam dynamics simulations including all known errors do not show uncontrolled beam losses in the linac, ion beam contaminants extracted from the ECR ion source together with main ion beam can produce significant losses after the charge stripper. These studies resulted in development of beam collimation system at relatively low energy of 16 MeV/u and room temperature bunchers instead of originally planned superconducting ones. Commissioning of the Front End enabled detailed beam physics studies accompanied with the simulations using several beam dynamics codes. Settings of beam optics devices from the ECR to MEBT has been developed and applied to meet important project milestones. Similar work is planned for the beam commissioning of the first 3 cryomodules in the superconducting linac.
