An advanced ISOL facility based on ATLAS

Abstract

AbstracL The Argonne concept for an accelerator complex for efficiently producing highquality radioactive beams from ion source energy up to 6-15 MeV/u is described. lle IsotopeSeparator-On-Lme (ISOL) method is used.A high-power driver accelerator produces radionuclides in a target that is closely coupled to an ion source and mass separator. By using a driver accelerator which can deliver a variety of beams and energies the mdionuclide production mechanisms can be chosen to optimize yields for the species of interest. To effectively utilize the high beam power of the driver two-step targetion source geometries are proposed (1) Neutron production with intermediate energy deuterons on a primary target to produce neutron-*38Utarge~and (2) Fragmentation of neutron-rich heavy ion rich fission products in a secondary beams such as '80 in a targetkatcher geometry. Heavy ion beams with total energies in the 1-10 GcV range are also available for radionuclide production via high-energy spallation reactions. At the present time R&D is in progress to develop superconducting resonator structures for a driver Iinac to cover the energy range up to 100 MeV per nucleon for heavy ions and 200 MeV for protons. lhe post accelerator scheme is based on using existing ISOL-type 1+ ion source technology followed by CW Radio Frequency Quadruple (RFQ) accelerators and superconducting linacs including the present ATLAS accelerator. A full-scale prototype of the first-stage RFQ has been successfidly tested with RF at fdl design voltage and tests with ion beams are in progress. A tenchmark beam, '32Sn@ 7 MeV/u, requires two stripping stages, one a gas stripper at very low velocity after the first RFQ section, and one a foil stripper at higher velocity after a superconducting-linac injector.

Future plans at ISOLDE

“…Furthermore, a new network (TARGISOL) has just been started with the aim to improve the understanding of (and to simulate) the complex processes involved in radioactive ion production, release, transport and ionization in a typical ISOL target-ion source unit [9,10]. An example of recent developments is the construction of so called neutron converter targets [11,12]. Such targets permit indirect production of radioactive ions through the neutrons emitted by a metallic rod fitted in parallel to the target container and irradiated by the driver proton beam.…”

Superconducting intermediate-velocity drift-tube cavities for the RIA driver linac

“…Recent development at ANL of SC niobium cavities has focused on accelerating structures suitable for the proposed rare isotope accelerator (RIA) [1,2]. In several earlier papers we have presented preliminary designs for a full set of drift-tube cavities suitable for the RIA driver linac [3,4].…”