Non-proportional scintillation response of NaI:Tl to low energy X-ray photons and electrons

TL;DR

This study investigates the non-proportional scintillation response of NaI:Tl to low-energy X-ray photons and electrons, revealing rapid variations near iodine K-edge and introducing K-dip spectroscopy for electron response analysis down to 30 eV.

Contribution

The paper introduces K-dip spectroscopy, a novel method for deriving the electron response curve of NaI:Tl at very low energies, enhancing understanding of its scintillation behavior.

Findings

Rapid response variation near iodine K-edge

K-dip spectroscopy effectively measures electron response down to 30 eV

Comparison with other methods highlights advantages and limitations

Abstract

Non-proportional response of the scintillation yield of NaI:Tl was measured using highly monochromatic synchrotron irradiation ranging from 9 to 100 keV. Special attention is paid to the X-ray escape peaks. They provide us additional information about non-proportional response in the range 0.9 to 12 keV. A rapid variation of the non-proportional response curve is observed near the Iodine K-electron binding energy. A dense sampling of data is performed around this energy and that data are used to apply a method, which we call K-dip spectroscopy. This method allows us to derive the electron response curve of NaI:Tl down to energies as low as 30 eV. A comparison of our data with data of others employing different methods is made. Advantages, limitations and peculiarities of presented techniques and methods are discussed.