Principle of single and multiple time interval analysis applicable to radioactive nuclides with half-lives of millisecond order

Simultaneous determination of radionuclides separable into natural decay series by use of time-interval analysis

“…where M is total count number, P(T) the probability of occurring within a time interval at T, t the differential time width, α t the probability of a daughter event due to the parent decay, λ the decay constant of apparently correlated events within a fixed time interval, and C the background or random event rate detectable by scintillation counting [2].…”

“…A delayed coincidence method, time-interval analysis (TIA), was originally developed in our laboratory to determine the thorium decay series in environmental samples by use of liquid scintillation counting with a personal computer [1,2,3,4]. The TIA method is based on measuring correlated α-decay events from daughter nuclides with lifetimes of the order of milliseconds or sub-milliseconds, thereby enabling their discrimination from random decay or background events [2,3].…”

“…The TIA method is based on measuring correlated α-decay events from daughter nuclides with lifetimes of the order of milliseconds or sub-milliseconds, thereby enabling their discrimination from random decay or background events [2,3]. Two different types of statistical analysis, single or multiple period time-interval analysis (STA and MTA, respectively) were evaluated using theoretical functions of the time interval distribution curve [2].…”

“…The TIA method is based on measuring correlated α-decay events from daughter nuclides with lifetimes of the order of milliseconds or sub-milliseconds, thereby enabling their discrimination from random decay or background events [2,3]. Two different types of statistical analysis, single or multiple period time-interval analysis (STA and MTA, respectively) were evaluated using theoretical functions of the time interval distribution curve [2]. From experimental data and simulation tests, an MTA method, which includes all pulse time intervals within a fixed time, was found to be more reliable for selective extraction of decay events with millisecond lifetimes [2,4].…”

“…Two different types of statistical analysis, single or multiple period time-interval analysis (STA and MTA, respectively) were evaluated using theoretical functions of the time interval distribution curve [2]. From experimental data and simulation tests, an MTA method, which includes all pulse time intervals within a fixed time, was found to be more reliable for selective extraction of decay events with millisecond lifetimes [2,4].…”