RADIOACTIVE DECAY AS A PERIODIC RANDOM PROCESS WITH POSITIVE FEEDBACK

Nearly all of geochronology is based upon the nuclear decay law in which the probability of radioactive decay within a given time period is a constant and independent of environmental or other conditions. However, a variety of recent experiments have suggested a periodicity in some radioactive decay schemes. For example, the β^- decay of ³²Si (T_1/2 = 172 ± 4 years) has been shown to have enhanced structure in the 10-15 year^-1 region, which was further shown to be independent of fluctuations in temperature, pressure and humidity. Proposed explanations for periodicity in radioactive decay have included the effect of solar neutrino flux, the impact of emitted particles on the decay of neighboring atoms, and other means by which members of a “cohort” of radioactive isotopes can “communicate” with one another. The objective of this study is to carry out numerical simulations to determine under what circumstances random processes with positive feedback can lead to periodicity in the probability of occurrence of a random process. The assumption is that the probability of radioactive decay of a given atom within a given time period is greater if one or more radioactive isotopes decayed during the previous time period. Periodicity in probability can occur only if the increment in probability can be both positive (radioactive decay of one atom makes decay of another atom more likely) or negative (the lack of radioactive decay of one atom makes decay of another atom or the same atom less likely). All numerical simulations are being carried out using the open-source Python programming language. Numerical results with implications for some radioactive decay schemes of geologic interest will be reported at the meeting.