A SUPERCONDUCTING MAGNETS SYSTEMS FOR A LOW BETA SECTION AT COSY AND AD

In the framework of the FAIR project (GSI, Darmstadt, D), the PAX collaboration has suggested new experiments using polarized antiprotons. 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 Forrschungzentrum Juelich, D) are to test our understanding of the spin-filtering processes and to commission the setup for the 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. Technical problems and details of the superconducting quadrupoles with their respective cryogenics will be discussed. A flexible cryogenic system fitting at COSY and AD ring characterized by a low liquid helium consumption will be discussed. The status of the construction of the quadrupoles will be reported as well