Building and Testing a Prototype For CAMEA

CAMEA (Countinuous Angle Multiple Energy Analyser) is a new concept for analysing inelastically scattered neutrons with high efficiency. It contains many (up to 10) vertically focusing analyser arrays behind each other, analysing the scattered neutrons with a given energy by scattering them vertically. Each array analyses different energies (Multiple Energy Analyser). The vertical scattering planes of analysers enable to cover large angular range in the scattering plane (Continuous Angle). Thus CAMEA gives a fast mapping possibilities in the three-dimensional q-E space spanned by the horizontal q-plane and the energy transfer. The large sample-analyser and analyser-detector distances provide clearly geometry limited energy resolution. This geometry combined with analyser crystals with relaxed mosaicity enable to use several detectors next to each other , seeing slightly different take-of angles, thus detecting neutrons with slightly different energies. Thus this concept has the advantages both of geometry limited resolution (high resolution) and mosaicity limited resolution (high analysing efficiency). CAMEA, as a secondary spectrometer can be optimally combined with a time of flight primary spectrometer resulting in an inverse geometry TOF spectrometer. ESS CAMEA is such an instrument proposed to be built at the ESS.