The AGFA and AIRIS separators at ATLAS

Physics Division, Argonne National Laboratory, Argonne, IL 60439, USA

Published online: 22 November 2017

Abstract

The ATLAS facility is being augmented with two new separators in order to take full advantage of recent and future anticipated beam intensity upgrades to the accelerator. A novel concept is used for the Argonne Gas-Filled Analyzer (AGFA), which employs only two magnetic elements; a quadrupole singlet for vertical focusing and a multipole magnet that provides a dipole field for the separation and a quadrupole field for horizontal focusing of the reaction products. The design allows for placing Gammasphere or GRETINA at the target position. This arrangement enables studies of prompt gamma-ray emission from weakly populated trans-fermium nuclei and those near the doubly-magic N=Z=50 shell closures measured in coincidence with the recoils registered in the AGFA focal plane. The Argonne In-flight Radioactive Ion Separator (AIRIS) is a magnetic chicane that will be installed immediately downstream of the last ATLAS cryostat. It will be used to separate radioactive ion beams generated in flight by the primary beam at an upstream high-intensity production target. These beams will be further purified by a downstream RF sweeper and transported to a number of target stations including HELIOS, the Enge spectrograph, the FMA and Gammasphere.