Spiral 2 is the next accelerator project at GANIL. It consists of a CW superconducting linac accelerating a 5 mA deuterons beam up to 40 MeV, and a target/source system for production of rare
isotopes. In addition, the linac is able to accelerate a 1 mA ion beam with q/A = 1/3 up to
14.4 MeV/u. The superconducting accelerating part of the linac is a combination of two
$\\beta$ families of quarter-wave and/or half-wave resonators. The RF base frequency is
88 MHz for the lower energy part and 176 MHz for the high energy section. A design
with a high energy part at 88 MHz is also evaluated. We review the RF optimisation
and properties of the quarter-wave resonators for the different beta and frequency
families. The mechanical aspects related to the frequency stability of the cavities,
namely helium pressure effects and tunability have been studied using coupled RF and
structural 3D codes.
|
