pile-up

in radioanalytical chemistry
https://doi.org/10.1351/goldbook.P04673
The processing by a radiation @S05837@ of pulses resulting from the simultaneous adsorption of independent particles or photons in a @R05054@. As a result they are counted as one single particle or photon with energy between the individual energies and the sum of these energies.
Sources:
Orange Book, 2nd ed., p. 235 [Terms]
PAC, 1994, 66, 2513. (Nomenclature for radioanalytical chemistry (IUPAC Recommendations 1994)) on page 2523 [Terms] [Paper]