Protactinium generator rvfm 52 2704 this protactinium generator is ideal for demonstrating radioactive decay the half life of the isotope is short enough for students to complete the decay curve within a single lesson and is perfect for use with a datalogger and gm tube sensor or a standard gm tube and counter the generator is completely sealed in a leakproof enclosure and consists of uranyl nitrate and an organic solvent these settle into two distinct layers but when shaken together react