ROTOR

The invention concerns a rotor combining the advantages of a single-piece wheel, which, when it is operating, only exhibits a slight and constant variation in shape (expansion shift) in the guiding region of its path, with those of a rimmed rotor with spokes, enabling, by virtue of its light weight, the bearings to be easily arranged. Further, because of its tendency to exhibit a tensile stress higher than a bending load, the rotor provides for a wide selection of rotor materials. The rotor has at least one segment arranged on the hub, enclosing at least a closed recess. A preferred embodiment concerns a rotor comprising at least three rotor segments uniformly distributed, said segments having each two recesses, such that the regions of materials surrounding them are in the form of three spokes arranged substantially parallel. The inventive rotor is particularly suitable for receiving graphite crystals, in the form or a vibrating disc for a back-scattering spectrometer.