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-${\hat{I}}^2$ insertion made it possible to achieve beam lifetimes of $\ddot{I}{„}_{\mathrm{b}}=8000$s in the presence of a dense polarized hydrogen storage-cell target of areal density $d_{\mathrm{t}}=(5.5\pm 0.2)\times 10^{13}atoms/c{\mathrm{m}}^2$. 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.