energy resolution

In physics, energy resolution refers to the ability of a detector system to distinguish between radiation quanta of slightly different energies. When radiation interacts with a detector, it deposits energy, generating a signal. Ideally, a single energy of radiation would produce identical signals. However, fluctuations in the signal amplitude occur, causing these signals to spread across a range of amplitudes in the recorded spectrum.

Energy resolution is quantified as the ratio of the peak's full-width at half-maximum (FWHM) to its centroid position, usually expressed as a percentage. A smaller percentage indicates a narrower peak and better resolution, allowing for clearer separation of distinct energy peaks in the spectrum. Causes of these fluctuations include detector operating parameter drifts, electronic noise, and fundamental statistical variations in the number of charge carriers produced. Detectors that generate more charge carriers per pulse generally exhibit better energy resolution.1