An easily constructed apparatus, of simple design, for measuring the Rutherford scattering of alpha particles by thin metal foils is described. An evacuated metal cylinder houses a movable system containing the alpha-particle emitter, a small 0.1 mC Po210 welded-foil source, and, at a fixed distance from this source, an annular ring of scattering material. The face of a type 5819 photomultiplier serves to seal the end of the vacuum chamber, and has at its center the detector, a small circular spot of ZnS(Ag) scintillator. The source, scatterer, and detector are coaxial. The scattering angle may be varied between 28° and 71° by changing the distance from the scattering annulus to the detector, with a resultant change in the counting rate from about 30/min to 4/min. Range and intensity measurements on the source are easily made. If common sense precautions are taken, no radiation hazards will be encountered.

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