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Ch. Gösselsberger, H. Abele, G. Badurek, E. Jericha, W. Mach, S. Nowak, T. Rechberger:
"Neutron beam tailoring by means of a novel pulsed spatial magnetic spin resonator";
Journal of Physics: Conference Series, 340 (2012), 012028; 1 - 8.

Since long neutron spin resonance in an arrangement of crossed homogeneous and spatially alternating transversal magnetic fields is known to allow for wavelength-selective polarisation manipulation. Combined with a pair of highly efficient polarising supermirrors it is an elegant method to single out a specific wavelength from an initially polychromatic polarised neutron beam, based upon the fact that in its rest frame each neutron creates its individual frequency. A spin flip process can then take place only if this individual frequency equals the neutron Larmor frequency in the homogeneous field. Here, we present the first experimental results we have obtained with a conceptually novel type of such spatial spin resonator, consisting of a series of separate modules which can be controlled independently from each other. Thus it becomes possible to vary e.g. the amplitude distribution of the spatially alternating transversal field without any geometric modification of the setup. Moreover this device fulfils the requirements for fast electronic switching of each module, which will be an important asset for the possible decoupling of the minimal neutron pulse duration and the achievable wavelength resolution. We compare the actual performance of this prototype resonator system with the theoretically expected behaviour.

Polarised neutrons, Magnetic spin resonator, Spin flipper, Neutron spectroscopy, Travelling magnetic fields, Velocity selector, neutron time-of-flight

http://dx.doi.org/10.1088/1742-6596/340/1/012028