An initially unpolarized beam of deuterons is found to acquire tensor polarization after traversing a foil of spin-zero target nuclei. The effect, called nuclear spin dichroism, has been predicted theoretically, albeit resulting in small values of $p_{zz}$ of the order of 0.01 for energies around 10 MeV. The experiment was carried out at the Köln tandem accelerator using carbon targets bombarded by deuterons. The observed polarization is as large as $p_{zz}=-0.28\pm 0.03$ for a beam of 14.8 MeV and a $129\mathrm{mg}/{\mathrm{cm}}^2$ target. The results allow one to produce tensor-polarized deuterons with $p_{zz}$ around $-0.30$ (or $+0.25$) from an initially unpolarized beam using a carbon target of appropriate thickness.

• Received 26 November 2009

DOI:https://doi.org/10.1103/PhysRevLett.104.222501