  Scattering experiments have revolutionized our understanding of nature.
Examples include the discovery of the nucleus, crystallography, and the
discovery of the double helix structure of DNA. Scattering techniques differ by
the type of the particles used, the interaction these particles have with
target materials and the range of wavelengths used. Here, we demonstrate a new
2-dimensional table-top scattering platform for exploring magnetic properties
of materials on mesoscopic length scales. Long lived, coherent magnonic
excitations are generated in a thin film of YIG and scattered off a magnetic
target deposited on its surface. The scattered waves are then recorded using a
scanning NV center magnetometer that allows sub-wavelength imaging and
operation under conditions ranging from cryogenic to ambient environment. While
most scattering platforms measure only the intensity of the scattered waves,
our imaging method allows for spatial determination of both amplitude and phase
of the scattered waves thereby allowing for a systematic reconstruction of the
target scattering potential. Our experimental results are consistent with
theoretical predictions for such a geometry and reveal several unusual features
of the magnetic response of the target, including suppression near the target
edges and gradient in the direction perpendicular to the direction of surface
wave propagation. Our results establish magnon scattering experiments as a new
platform for studying correlated many-body systems.
