The Protactinium Generator is a convenient way to bring the phenomenon of radioactive decay into the classroom. With a half life of the order of a minute, students have the opportunity to record a complete decay curve in a single lesson.
It presents an ideal opportunity to use a data logger with a radioactive count rate sensor to record the activity, and compare it to a predicted decay curve.
Protactinium234 has a half-life of about 70 seconds, and is ideal for the observation of radioactive decay. The isotope is a product of the Uranium238 decay series.
The generator contains a uranium salt in acidic solution, plus a water-immiscible organic liquid. Pa234 is soluble in this organic liquid. When the liquids are shaken together, the organic solvent selectively extracts the Pa234. When allowed to resettle, a physical separation into two layers occurs, any Pa234 is in the upper organic layer. The Pa234 decay is monitored by a Geiger tube placed close to the top of the container, supported by a stand and clamp. Over a period of 5 to 10 minutes a clear half-life curve can be captured, manually or using a datalogger. Several factors combine to ensure that Pa234 clearly exhibits its own half-life:
• Other decay products remain in the lower aqueous layer; alpha and beta radiation from these cannot penetrate the container.
• Pa234 is a beta emitter with an energy spectrum going up to 2.3 MeV, sufficient to penetrate both the walls of the flask and some of the liquid in which the source is contained.
The generator is supplied in a sealed translucent container, which is virtually chemically inert with a leak-proof closure. This is packed in an outer container which is suitable for long term storage. The generator can be stored for a period of eight years, after which time disposal should be made through a commercial disposal agency or via the local authority.
Please note this is a non-returnable item.
Please note: Retort stand, Base, GM Tube, holder and scaler timer not included.