Overview of the U.S. rare isotope accelerator proposal

Abstract

The Rare Isotope Accelerator (RIA) is the highest priority of the nuclear physics community in the United States for a major new facility. RIA is a next generation facility for basic research with radioactive beams that utilizes both standard Isotope-separator On-line (ISOL) and in-flight fragmentation methods with novel approaches to handle high primary-beam power and remove existing limitations in the extraction of short-lived isotopes. A versatile primary accelerator, a 1.4-GV, CW superconducting linac designed to simultaneously accelerate several heavy-ion charge states, will provide beams from protons at 900 MeV to uranium at 400 MeV/u at power levels of 400 kW. The wide variety of primary beams allows various production and extraction schemes to be used to optimize production of specific isotopes. These isotopes, at unprecedented intensities, are available for research at a broad range of energies. They can be delivered at ion source energy for stopped-beam studies, reaccelerated by a second superconducting linac, or directly separated in-flight for use at energies up to 500 MeV/u. The post accelerator uses a unique injection scheme, based on CW low-frequency RFQs, for efficient acceleration of singly charged heavy ions with masses up to 240 amu from ion source energy.