Characterization of an RFQ equipped with real IPHI profile electrodes

We have demonstrated the validity of our formalism for tuning a Radio Frequency Quadrupole (RFQ) cavity equipped with constant-profile electrodes. In particular, we applied this formalism to obtain a constant or variable voltage profile in a 2-meter RFQ, featuring a continuous electrode along its entire length, or made up of the assembly of 2 RFQs of 1 meter each joined through a resonant coupling. It remained to demonstrate the validity of our formalism applied to the real case, where the transverse cross-section of the electrodes is variable and the resonant frequency of the transverse cross-section is longitudinally modulated. For the two piston cross-section distributions tested, all parameters converged perfectly in 4 iterations. These tests validate: the end-loaded inhomogeneous quadrifilar line model we built to tune IPHI's RFQ; piston response calculations performed using Superfish driven from a Matlab code. The tuning piston tuning formalism applies perfectly to a real RFQ segment, even if it is not followed by the next segment and therefore presents a mismatch at the 'resonant coupling' end. The method for calculating piston drives, which allows even irregular piston distribution to be considered, has been validated. Measurements on the individual RFQ section provide an excellent repeat of the diagnostics to be carried out on the industrial site before and after soldering. The longitudinal distributions of capacitive faults in quadrants 1 to 4 are superimposed for all measurements, with or without dipolar adjustment fingers. Disturbance measurements show a signal-to-noise ratio and repeatability that are perfectly satisfactory for this diagnosis. The cylindrical section closure block plays its role perfectly. Measurement alignment methods for this mechanical configuration have been validated. Our estimation of the voltage slopes at the ends enables us to correctly estimate the transverse imbalances of the electrodes, independently of the boundary conditions