7-order enhancement of the Stern-Gerlach effect of neutrons diffracting in a crystal

Abstract

We measured the spatial splitting of a non-polarized neutron beam passed through a crystal under diffraction conditions in heterogeneous magnetic field (analog to the Stern-Gerlach effect) into two polarized components with opposite polarization. The measurements were carried out using Laue diffraction scheme, small gradients of the magnetic field and Bragg angles close to orthogonality θB=(78−82)∘. After a flight path in crystal of 21.6 cm a splitting of 4.1±0.1 cm was achieved (using a field gradient of ∼3 G/cm and a diffraction angle of 82∘). In the absence of a diffraction (crystal) but otherwise the same flight path and field gradient the spatial splitting would be ∼4⋅10−7 cm. From those we deduce an experimental amplification factor in the order of about ∼2⋅105tan2⁡θB due to the use of diffraction in crystals, which agrees with theory.

Keywords

• Neutron
• Single crystal
• Stern-Gerlach effect
• Dynamic diffraction
• Magnetic field
• Equivalence principle