Needle sources are used to generate a point source of radiation inside cloud chambers for demonstrating alpha and beta radiation tracks. Three different types of isotopes are offered, a pure alpha emitter, a pure beta emitter and a combined alpha /beta emitter.

The sources are constructed by depositing a small, license exempt quantity of radioactive isotope onto the eye of a standard sewing needle which is mounted on a test tube stopper for insertion into the could chamber. The needle and stopper are placed into test tube for protection during shipping and storage.

NS-Po210

Po-210 Needle. This alpha emitter contains 0.01 microcuries of Polonium-210.

NS-Sr90

Sr-90 Needle. A beta emitter containing 0.01 microcuries of Strontium-90.

NS-Pb210

Pb-210 Needle. 0.01 microcuries of Lead-210 in equilibrium with its daughters Bi-210 and Po-210, produces a source of both alpha and beta particles.