RF Measurements and Tuning of the PIXE-RFQ

CERN has built a 750 MHz radio-frequency quadrupole (RFQ), called PIXE-RFQ, for proton-induced X-ray emission analysis (PIXE) of cultural heritage artwork. The PIXE-RFQ is part of the MACHINA collaboration (Movable Accelerator for Cultural Heritage In-situ Non-destructive Analysis) between CERN and INFN, and the second RFQ worldwide to operate at this high frequency. The standalone PIXE-RFQ accelerates protons to 2 MeV over a length of one meter. It features two individually brazed modules, sixteen slug tuners, and a single power coupler. By mid-2020, RF measurements of the RFQ and its components, as well as field and frequency tuning have been completed. Results and the novel tuning procedure are reported in this note.