Toward polarized antiprotons: Machine development for spin-filtering experiments

The paper describes the commissioning of the experimental equipment and the machine studies required for the first spin-filtering experiment with protons at a beam kinetic energy of $49.3,$MeV in COSY. The implementation of a low-$beta$ insertion made it possible to achieve beam lifetimes of $tau_{rm{b}}=8000,$s in the presence of a dense polarized hydrogen storage-cell target of areal density $d_{rm t}=(5.5pm 0.2)times 10^{13},mathrm{atoms/cm^{2}}$. The developed techniques can be directly applied to antiproton machines and allow for the determination of the spin-dependent $bar{p}p$ cross sections via spin filtering.