The phenomenology and present theoretical understanding of energy nonlinearity (nonproportionality) in radiation detection materials is reviewed, with emphasis on gamma-ray spectroscopy. Semiconductor detectors are extremely linear, while scintillators display varying degrees and patterns of nonlinearity, and gas detectors show a characteristic form of nonproportionality associated with core levels. The relation between nonlinear response (to both primary particles and secondary electrons) and spectrometer resolution is also discussed. We review the qualitative ideas about the origin of nonlinearity in scintillators that have been proposed to date, with emphasis on transport and recombination of information carriers. Recent computational and experimental work on the basic physics of scintillators is leading towards a better understanding of energy nonlinearity and should result in new, more linear scintillator materials in the near future.
Revised: April 27, 2011 |
Published: January 1, 2007
Citation
Jaffe J.E., D.V. Jordan, and A.J. Peurrung. 2007.Energy Nonlinearity in Radiation Detection Materials: Causes and Consequences.Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment 570, no. 1:72-83.PNNL-SA-48762.doi:10.1016/j.nima.2006.09.097