FRIB, East Lansing, Michigan, USA
INFN/LNL, Legnaro (PD), Italy
KEK, Ibaraki, Japan
ANL, Argonne, Illinois, USA
TRIUMF, Vancouver, Canada
JLab, Newport News, Virginia, USA
The Facility for Rare Isotope Beams' heavy ion con-tinuous-wave (CW) linac extends superconducting RF to low beam energy of 500 keV/u. 332 low-beta cavities are housed in 48 cryomodules. Technical development of high performance subsystems including resonator, cou-pler, tuner, mechanical damper, solenoid and magnetic shielding is necessary. In 2015, the first innovatively designed FRIB bottom-up prototype cryomodule was tested meeting all FRIB specifications. In 2016, the first full production cryomodule is constructed and tested. The preproduction and production cryomodule procurements and in-house assembly are progressing according to the project plan.
Fermilab, Batavia, Illinois, USA
CERN, Geneva, Switzerland
LBNL, Berkeley, California, USA
BNL, Upton, Long Island, New York, USA
The High Luminosity upgrade of the LHC at CERN will use large aperture (150 mm) quadrupole magnets to focus the beams at the interaction points. The high field in the coils requires Nb3Sn superconductor technology, which has been brought to maturity by the LHC Accelerator Research Program (LARP) over the last 10 years. The key design targets for the new IR quadrupoles were established in 2012, and fabrication of model magnets started in 2014. This paper discusses the results from the first single short coil test and from the first short quadrupole model test. Remaining challenges and plans to address them are also presented and discussed.
Fermilab, Batavia, Illinois, USA
Proton Improvement Plan-II at Fermilab is an 800 MeV superconducting pulsed linac which is also capable of running in CW mode. The high energy section operates from 185 MeV to 800 MeV instigated using 650 MHz elliptical cavities. The low-beta (LB) βG =0.61 portion will accelerate protons from 185 MeV-500 MeV, while the high-beta (HB) βG = 0.92 portion of the linac will acceler-ate from 500 to 800 MeV. The development of both LB and HB cavities is taking place under the umbrella of the Indian Institutions Fermilab Collaboration (IIFC). This paper presents the design methodology adopted for both low-beta and high-beta cavities starting from the RF design yielding mechanical dimensions of the cavity cells and, then moving to the workable dressed cavity design. Designs of end groups (main coupler side and field probe side), helium vessel, coupler, and tuner are the same for both cavities everywhere where it is possible. The design, analysis and integration of dressed cavity are presented in detail.
WEB3CO04
University of Chicago, Chicago, Illinois, USA
Oxygen plasmas have shown promise for removing surface hydrocarbons from niobium in superconducting RF cavities. These techniques are candidates for in-situ cleaning techniques for installed accelerating cavities. The goal is to improve the performance of cavities that have degraded over time, without removing them from their cryomodule. By varying the governing parameters of the plasma, the primary cleaning method can be varied between a primarily physical process (sputtering) and a primarily chemical process. We extend this work from organic contaminants to more general contaminants, including metallic species. These preliminary tests are primarily concerned with characterizing the cleaning power of various plasma compositions. A variety of gas species are used to create different plasma compositions, including Ar, Ne, O2, N2, H2, and He. Cleaning power is determined by performing surface characterization analysis on room-temperature niobium samples before and after plasma treatment. Samples are maintained in a clean environment between characterization and treatment, to prevent surface recontamination. Measurements of surface contamination and surface character are presented.