Determination of deuteron beam polarizations at COSY

Abstract

The vector (${P}_{z}$) and tensor (${P}_{zz}$) polarizations of a deuteron beam have been measured using elastic deuteron--carbon scattering at 75.6 MeV and deuteron-proton scattering at 270 MeV. After acceleration to 1170 MeV inside the COSY storage ring, the polarizations of the deuterons were remeasured by studying the analyzing powers of a variety of nuclear reactions. For this purpose a hydrogen cluster target was employed at the ANKE magnetic spectrometer, which is situated at an internal target position in the ring. The overall precisions obtained were about 4% for both ${P}_{z}$ and ${P}_{zz}$. Though all the measurements were consistent with the absence of depolarization during acceleration, only an upper limit of about 6% could be placed on such an effect.