Radiofrequency Quadrupole Accelerators for the RIA Facility

Andrei Kolomiets, IETP, Moscow

The Rare Isotope Accelerator (RIA) Facility will consist of several Radio-Frequency Quadrupole (RFQ) sections since RFQs are most efficient for acceleration of low-velocity ions. The primary design goal for the Driver RFQ is to establish a low output emittance so that the acceleration of multiple-charge-state beams through the rest of the linac becomes straightforward. Low longitudinal emittance is achieved by using an external multi-harmonic buncher and an RFQ of modified design. Three RFQ sections operating at very low frequencies 12 MHz and 24 MHz were designed for the acceleration of radioactive ions including singly charged ions with mass number up to 240. To increase acceleration efficiency a special accelerating structure, so-called Hybrid RFQ, was proposed and designed.

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