FRIB, East Lansing, Michigan, USA
NSCL, East Lansing, Michigan, USA
The ReA-RFQ is a four-rod room-temperature structure aimed to be the first step acceleration of rare isotopes as well as stable beams before injection into the ReA SRF linac. The beams of charge to mass ratios of 1/5 to 1/2 from the Electron Beam Ion Trap at 12 keV/u should be accelerated to at least 500 keV/u to be efficiently accelerated in the main SRF linac. Since the commissioning of the original ReA RFQ in 2010 the design voltage has never been reached, and CW operation was never achieved due to cooling issues. In 2016 a new design including trapezoidal modulation was proposed, which permitted achieving increased reliability, and would allow reaching the original required specifications. The proposed new rods were built and installed in 2019 and commissioned in the same year. Since then, the RFQ has been working very successfully. Recently it was opened for inspection and verification of its internal status. No damage and discoloration were observed. This contribution will describe the RFQ rebuild process, involving specific RF protections and other technical aspects related to the assembly of the structure. Results of the operation with a variety of beams will be presented.
FRIB, East Lansing, Michigan, USA
NSCL, East Lansing, Michigan, USA
INFN/LNL, Legnaro (PD), Italy
KEK, Ibaraki, Japan
ANL, Lemont, Illinois, USA
TRIUMF, Vancouver, Canada
JLab, Newport News, Virginia, USA
The Facility for Rare Isotope Beams (FRIB) project has completed technical construction in January 2022, five months ahead of schedule baselined about 10 years ago. Beam commissioning has been planned in seven phases starting from 2017 when the normal-conducting ion source and RFQ were commissioned. In April 2021, FRIB driver linac commissioning was completed with heavy ion beams being accelerated to energies above 200 MeV/u using 324 superconducting radiofrequency (SRF) resonators contained in 46 cryomodules. In preparation for high-power operations, a liquid lithium charge strip-per was used to strip uranium beam from average charge state of 33+ to 78+, and multiple charge states were accelerated simultaneously in the linac. By January 2022, FRIB target and fragment separator commissioning was completed with rare-isotope beams produced and identified. In May 2022, the first FRIB user scientific experiment was successfully conducted. This talk summarizes the FRIB accelerator project commissioning and early operations experience with discussions on strategic planning, operational envelope conformance, technical risk mitigation, and lessons learned.
