Toward polarized antiprotons: Machine development for spin-filtering experiments

Abstract

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-$\ensuremath{\beta}$ insertion made it possible to achieve beam lifetimes of ${\ensuremath{\tau}}_{b}=8000\text{ }\text{ }\mathrm{s}$ in the presence of a dense polarized hydrogen storage-cell target of areal density ${d}_{t}=(5.5\ifmmode\pm\else\textpm\fi{}0.2)\ifmmode\times\else\texttimes\fi{}\phantom{\rule{0ex}{0ex}}1{0}^{13}\text{ }\text{ }\mathrm{atoms}/{\mathrm{cm}}^{2}$. The developed techniques can be directly applied to antiproton machines and allow the determination of the spin-dependent $\overline{p}p$ cross sections via spin filtering.