Segmented resonantly coupled radio-frequency quadrupole (RFQ)

In this experiment a 4-m-long radio-frequency quadruple (RFQ) resonating at 348 MHz was split into two 2-m-long RFQs. The two RFQs were then rejoined with resonant coupling to form a segmented 4-m-long RFQ. This coupling improved both the longitudinal and transverse stability of the 4-m-long RFQ. The frequencies of all the-modes near the RFQ mode and the sensitivity of the RFQ mode to perturbations were measured. This paper presents the results of these measurements and the compares them with measurements of the original 4-m-long RFQ. Both the original RFQ and the resonant-coupled RFQ use four rods (dipole stabilizers) on the end plates to adjust the frequencies of the dipole modes. Slug tuners distributed along its outer walls tune the RFQ. Modifications to the program RFQTUNE allow its use for tuning the segmented RFQs. This paper also describes the tuning procedure.<>