Abstract
The Facility for Rare Isotope Beams (FRIB) is designed to accelerate ion beams to ≥ 200 MeV per nucleon with 46 superconducting radio-frequency cryomodules. The FRIB driver linac uses quarter-wave resonators and half-wave resonators; with a total of 324 resonators, the linac is currently the largest heavy ion accelerator in the world. Production of jacketed resonators began in January 2014 and was completed in December 2019. Dewar certification testing of all the cavities was done before they were installed into cryomodules. The experience and lessons from more than 5 years of FRIB resonator production and certification testing are analyzed and summarized in this paper.
| Original language | English |
|---|---|
| Article number | 165675 |
| Journal | Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment |
| Volume | 1014 |
| DOIs | |
| State | Published - Oct 21 2021 |
| Externally published | Yes |
Funding
The Facility for Rare Isotope Beams (FRIB) is a new user facility for research in nuclear science, funded by the U. S. Department of Energy Office of Science. The FRIB driver linac builds on the SRF expertise in development for ion acceleration since the 1970s. The driver linac is designed to accelerate beams of stable ions of all types (from hydrogen to uranium) up to 200 MeV per nucleon or higher, with a beam power of up to 400 kW on the target. As the average beam power is two orders of magnitude higher than operating heavy-ion facilities, FRIB will be at the power frontier for nuclear science facilities [9,10] . The accelerator consists of three linac segments connected by 2 bending sections, with a total length of about 500 m. Technical construction and phased beam commissioning at Michigan State University (MSU) are nearing completion. Fig. 1 shows the facility layout. The work reported in the paper would not have been possible without the SRF cavity fabrication quality and schedule control work by Chris Compton and his team, including cavity inspection work by Jesse Craft and Joseph Asciutto; SRF cavity surface preparation work done by the FRIB team, led by Kyle Elliott, Ethan Metzgar, and Laura Popielarski; and the support of the FRIB cryogenics team. We appreciate the work by David Norton, John Schwartz, and Greg Velianoff in preparing and assisting with certification testing. We thank Zhihong Zheng for his past contributions to our cavity certification efforts. Additional testing of FRIB resonators was done by Michael Kelly and colleagues at Argonne National Laboratory. Samuel Miller, Chris Compton, and Laura Popielarski provided drawings and photographs for this paper. We thank Alberto Facco (INFN-Legnaro) and Robert Laxdal (TRIUMF) for their service as advisors to our project; we appreciate the comments and suggestions Alberto provided to help improve this paper. This work was supported by the US Department of Energy Office of Science under cooperative agreement DE-SC0000661. This work was supported by the US Department of Energy Office of Science under cooperative agreement DE-SC0000661 .
Keywords
- Dewar test
- Field emission
- Indium seal
- Multipacting
- Superconducting cavity
- Thermal breakdown