Helium-jet system for radioactivity studies

A helium-jet sample-deposition and tape-transport system has been constructed for studying short-lived radioactivities produced by accelerator bombardment. A novel feature consists of the use of a single loop of tape approximatley 150 cm long having punched sprocket holes. This is driven by a fast tape reader (157 cm/s tape speed) responding to a circuit that allows the tape to advance on each cycle by 120 sprocket holes, moving a source 30.5 cm from the jet to the detectors in 0.2 s. Depending on the exact length of tape 29 to 119 separate sample depositions can be measured before repeating the first spot or changing tapes. All combinations of β, γ, delayed α or proton spectra from radioactivities of Tsub(1/2) > approximately 0.2 s can be measured in singles or in coincidence with this device. (Auth.)