Radiation counter

Radiation counter

Counter counts depend on which decay signals are registered. Here efficiency means an overall count probability per decay, including the modeled emission and detection pathway. Background adds expected counts independently. Under the stated Poisson counting model, gross-count variance equals its expectation. The square root of expected gross counts is the model standard deviation, not an observed error bar or a confidence interval.

• Efficiency and background remain constant during each window; detector dead time, pileup, and correlated events are omitted.
• The Poisson result is a counting approximation, separate from exact statistics for a fixed finite inventory.
• The output identifies neither an isotope nor a dose or geological age.