3D printed magnets for neutron spin manipulation

Devices for manipulation of the neutron spin are vital for experiments in neutron optics such as neutron interferometry. Here we introduce a new type of such devices which are based on a magnetic material that can be 3D printed in complex shapes. We have constructed a spin flipper wherein the angle of spin rotation can be adjusted by variation of the distance between magnetized pieces. As the device does not contain any heat dissipating coils we expect interferometric measurements to become more stable and hence more accurate. Results of an experiment using polarized neutrons verify the device's functionality, and indicate the potential of the new method. A second experiment for demonstration of the 4π spinor symmetry of fermionic wave functions is in progress.