total efficiency

Detection efficiency in radiation measurement refers to the probability that a quantum of radiation incident on a detector will produce a recorded pulse. This is crucial for accurate measurements, especially with low-intensity radiation, as it minimizes the time needed to gather sufficient data.1

There are two main types of detection efficiency:
* Total efficiency: The probability that any pulse is produced, regardless of its size.1
* Peak efficiency: The probability that the incident quantum deposits all its initial energy within the detector.1

For charged particles like alpha and beta particles, total efficiency is often close to 100% because they begin depositing energy immediately upon entering the detector. For gamma rays, however, total efficiency can be significantly less than 100% because photons may pass through the detector without interacting. Peak efficiency is generally lower than total efficiency because it requires the full energy to be deposited, which is not always the case, especially with gamma rays. Efficiency values are influenced by the type and energy of the radiation, as well as detector characteristics like thickness and material composition.1