Abstract

A method is shown to extract the average quantum energy of radiation from measurements of intensity and its statistical variance. The simple result is general for radiations and detectors where the registered intensity is proportional to the energy of detected quanta. The assertion is demonstrated analytically, experimentally, and in Monte Carlo simulations, while the conceptual limits of its resolution, capacity to quantify the detector’s inner workings and viability are outlined. Its practical utility has been overlooked in applications, of which a few are indicated.