First observation of trapped high-field seeking ultracold neutron spin states

Ultracold neutrons were stored in a volume, using a magnetic dipole field shutter. Radial confinement was provided by material walls. Low-field seeking neutrons were axially confined above the magnetic field. High-field seeking neutrons are trapped inside the magnetic field. They can systematically shift the measured neutron lifetime to lower values in experiments with magnetic confinement. ISSN:0370-2693 ISSN:0031-9163 ISSN:1873-2445