High-energy heavy ion cocktail beams at the 88 Inch Cyclotron (abstract)

The combination of cyclotron and electron cyclotron resonance (ECR) ion source provides the ability to accelerate “cocktails” of ions, mixtures of ions of near-identical charge-to-mass ratio. This concept was developed soon after the first ECR ion source became operational at the 88 Inch Cyclotron and has become a powerful tool in the field of heavy ion radiation effects testing. The standard 4.5 MeV/nuc cocktail at a charge-to-mass ratio of 0.2 contains ions from B 2+ to Bi 41+ . Copper and cobalt are provided by the direct insertion method, B is produced utilizing the MIVOC technique and Bi is produced with the oven technique. Recently, following upgrades to the AECR and the cyclotron vacuum system, a new high-energy heavy cocktail beam has been developed. This cocktail at a charge-to-mass ration of 0.27 using 400 MeV Ar 11+ as a “pilot” beam, contains ions from B 3+ to Xe 38+ and provides accelerated ions with a range of 100 μm in Si, of great advantage for some of the newer-generation microelectronics. It has joined the 4.5 MeV/u heavy ion cocktail and the 32.5 MeV/u light ion cocktail as standards in the cyclotron’s cocktail repertoire.