Needle source is used to generate a point source of radiation inside cloud chambers for demonstrating alpha and beta radiation tracks. A replacement part for Diffusion Cloud Chambers (SE-7943, SE-7944A).
The source is constructed by depositing a small quantity of radioactive isotope onto the eye of a standard sewing needle which is mounted on a test tube stopper for insertion into the cloud chamber. The needle and stopper are placed into a test tube for protection during shipping and storage.
The source is USNRC License Exempt (US only). Outside the US, consult local laws and regulations.