The coupled cyclotron project at the NSCL

Abstract

The NSCL has proposed an upgrade to its facility to provide primary beams of significantly higher intensity and higher energy needed for studies of nuclear reactions and nuclear structure, particularly to provide those primary beams needed to produce intense secondary beams. The project consists of building a high current injection line, refurbishing the existing K500 cyclotron for stable high intensity operation, coupling to the existing K1200 cyclotron, and replacing the A1200 fragment separator with a new high acceptance device (called the A1900). The new fragment separator will connect on to the existing beamlines and provide the higher intensity beams to the experimental equipment. Large gains in primary beam intensity, typically two or three orders of magnitude, will result from accelerating low charge-state ions in the first accelerator followed by stripping and further acceleration in the second machine. Additional large gains in the intensity of the secondary beams will come from the very high acceptance of the A1900 fragment separator. The new separator, relying on large superconducting magnets, will accept over 90% of a variety of secondary beams. The ready availability of intense beams over the entire range of atomic number and masses will open new vistas in nuclear structure through the production and study of many new and previously inaccessible nuclei. Research into the production and transport of intense beams from the ion source is underway as is the design of the A1900 superconducting quadrupoles and dipoles. An overview of the project will be presented.