To test a hypothesis regarding acceleration of alpha decay via cavitation I made an aqueous solution of uranyl nitrate and deposited it into the Branson sealed atmospheric chamber – Fig. 1.

The chamber was filled with the uranyl nitrate solution to the brim with no air space and cooled by running water through the water jacket, which is a part of the sealed atmospheric chamber. To measure the solution’s activity I used Bicron 2M2 NaI(Tl) detector connected to PicoScope 4262 running PulseCounter software.

Baseline uranyl activity was 230 CPS. During cavitation (which lasted for 10 minutes per experiment) the activity initially dropped to 194 CPS due to uranyl dissolution and perhaps sorption. However, the activity remained unchanged at ~195 CPS throughout subsequent cavitation experiments, which ranged in power from 10, 20 and 100% – Fig. 2.

Counts during the first experiment (measurement 3E) are shown on Fig. 3.

The counts rapidly drop from the initial value around 230 CPS as cavitation promotes salt dissolution, convection and sorption throughout the cavitation chamber. The counts quickly stabilize at the ~195 CPS level following the first minute and remain at this level in subsequent experiments.

Conclusion

The initial drop of activity due to dissolution / sorption is significant and can be easily mistaken for a genuine reduction in activity by an inexperienced researcher. However, prolonged cavitation of aqueous solution of uranyl nitrate does indicate a reduction in activity.