A low beta section for polarization studies of antiprotons by spin filtering

In the framework of the FAIR [1] project, the PAX collaboration has suggested new experiments using polarized antiprotons [2]. The central physics issue is now to study the polarization build-up by spin filtering of antiprotons via multiple passages through an internal polarized gas target. The goals for spin-filtering experiments with protons at COSY are to test our understanding of the spin-filtering processes and to commission the setup for the AD experiments with antiprotons at the AD (CERN). Spin-filtering experiments with antiprotons at the AD will allow us to determine the total spin-dependent transversal and longitudinal cross sections. The low-beta section at COSY is composed of two superconducting quadrupole magnets on each side of the target, while at the AD, we will use three quadrupoles on each side. Accelerator technical problems and details for COSY and AD to carry out the planned spin-filtering studies together with the technical problems and details of the superconducting quadrupoles will be discussed in this paper.