High intensity heavy ion beams for exotic nuclei production at GANIL

The GANIL heavy ion accelerator can be used as a driver for producing exotic beams either by fragmentation of the projectile, or by the ISOL method through the SPIRAL complex. The accelerator was first equipped with several devices for protection against thermal effects and activation. Then tests were carried out to increase the primary beam intensities, especially for projectiles ranging from C to Ar. The goal of 2×1013 pps was obtained with a 75 MeV/n carbon beam extracted from SSC2 for several hours. Losses at extraction limited the Ar intensity to 5×1012 pps, while a 1×1013 pps was aimed at. For some other ion species, substantial increases were obtained, although their use are somewhat limited by weaknesses in the concrete shielding. Detailed results of these tests are discussed. Possible cures to overcome limitations are presented, along with results of simulations concerning the effect of longitudinal space charge forces.