Bonn 2010 – wissenschaftliches Programm
HK 7.1: Gruppenbericht
Montag, 15. März 2010, 16:30–17:00, JUR B
Production of a beam of tensor-polarized deuterons using a carbon target — •Hellmut Seyfarth1, Ralf Engels1, Frank Rathmann1, Hans Ströher1, Vladimir Baryshevsky2, Anatoli Rouba2, Carsten Düweke3,4, Reinhard Emmerich3,5, Astrid Imig3,6, Kirill Grigoryev1,7, Maxim Mikirtychiants1,7, and Alexander Vasilyev7 — 1IKP, FZ Jülich, 52425 Jülich, Germany — 2Res. Inst. Nucl. Probl., 220050 Minsk, Belorus — 3IKP, Universität zu Köln, 50937 Köln — 4now AREVA NP GmbH, 91058 Erlangen, Germany — 5now TU München, Phys. Dpt. E18, 85748 Garching, Germany — 6now Brookhaven Nat. Lab., Upton, NY 11973, USA — 7Petersburg Nucl. Phys. Inst., 188300 Gatchina, Russia
An initially unpolarized beam of deuterons is found to acquire tensor polarization after traversing a foil of spinless target nuclei. The experiment was performed with unpolarized deuteron beams of 9.5 to 18.7 MeV from the Köln tandem accelerator. The polarization of the beam behind graphite targets of areal densitites between 36 and 188 mg/cm2 was measured with a polarimeter based on the d→+3He→ p+4He reaction. This effect, called nuclear spin dichroism, has been predicted theoretically, albeit resulting in small values of pzz of the order of 0.01 for energies around 10 MeV. The observed polarization, however, reaches a value as large as pzz=−0.28 ± 0.03 for an initial beam energy of 14.8 MeV and a 129 mg/cm2 target. The results, which allow one to produce tensor-polarized deuterons with pzz≈−0.30 (or +0.25) from an initially unpolarized beam using graphite targets of appropriate thickness, are presented and discussed.