2014/11/13 by Dan Gonnella, D. Gonnella, Ralf Eichhorn +29 · 1 citation
Engineering · Physics and Astronomy · #Beam (structure) #Linear particle accelerator #Magnetic field #Niobium #Niobium-tin #Particle Accelerators and Free-Electron Lasers #Particle accelerator #Particle accelerators and beam dynamics #Residual #Superconducting radio frequency #Superconductivity in MgB2 and Alloys #physics.acc-ph
paper · pdf · doi:10.1063/1.4905681
11 pages, 22 figures
arxiv created 2014/11/13 · openalex publication_date 2015/01/13 · arxiv updated 2015/01/15 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The superconducting RF linac for Linac Coherent Light Source-II calls for 1.3 GHz 9-cell cavities with an average intrinsic quality factor Q0 of 2.7 × 1010 at 2.0 K and 16 MV/m accelerating gradient. Two niobium 9 cell cavities, prepared with nitrogen-doping at Fermilab, were assembled into the Cornell Horizontal Test Cryomodule (HTC) to test cavity performance in a cryomodule that is very similar to a full LCLS-II cryomodule. The cavities met LCLS-II specifications with an average quench field of 17 MV/m and an average Q0 of 3 × 1010. The sensitivity of the cavities' residual resistance to ambient magnetic field was determined to be 0.5 nΩ/mG during fast cool down. In two cool downs, a heater attached to one of the cavity beam tubes was used to induce large horizontal temperature gradients. Here, we report on the results of these first tests of nitrogen-doped cavities in a cryomodule, which provide critical information for the LCLS-II project.