Münster 2011 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
HK: Fachverband Physik der Hadronen und Kerne
HK 60: Instrumentierung XI
HK 60.4: Vortrag
Donnerstag, 24. März 2011, 17:15–17:30, HS1
An Opaque Test-Bench For High Precision Neutron Spin Polarization Measurements — •Christine Klauser1,2, Jérémie Chastagnier2, David Jullien2, Alexander Petoukhov2, and Torsten Soldner2 — 1Technische Universität München, D-85748 Garching, Germany — 2Institut Laue-Langevin, F-38042 Grenoble, France
Very high spin polarization is important, notably when measuring absolute values of correlation coefficients in neutron β-decay. We have set up a test-bench employing two opaque 3He-cells with in-situ spin flipping of the helium. These cells have been used to polarize a neutron beam to more than 99.99 % and to analyze its polarization with high accuracy. We validated the accuracy of polarization analysis with opaque 3He-cells to be better than 10−4 relative. State-of-the-art polarizing super mirrors in X-SM geometry deliver about 99.7% polarization. Our test-bench gave direct evidence that this polarization is limited by depolarizing effects in the polarizing super mirror. The set-up was also used to show the high efficiency of a radio-frequency spin flipper and to explore its wavelength dependency. In the future, this test-bench will be used to explore methods to reduce depolarization effects in super mirrors. In neutron scattering, it provides an sensitive tool to study depolarization in samples.