Toward polarized antiprotons: Machine development for spin-filtering experiments

TL;DR

This paper reports on the development and commissioning of a machine setup for spin-filtering experiments with protons, aiming to facilitate polarized antiproton production by measuring spin-dependent cross sections.

Contribution

It introduces new machine techniques and experimental procedures for spin-filtering with protons, applicable to antiproton polarization studies.

Findings

Achieved beam lifetimes of 8000 seconds with dense polarized targets.

Implemented low-beta insertion enabling effective spin-filtering experiments.

Techniques developed are directly applicable to antiproton polarization measurements.

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-$\beta$ 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 $d_{\rm t}=(5.5\pm 0.2)\times 10^{13}\,\mathrm{atoms/cm^{2}}$. 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.