Nonproportional Response Between 0.1–100 keV Energy by Means of Highly Monochromatic Synchrotron X-Rays

Abstract

Abstract-Using highly monochromatic X-ray synchrotron irradiation ranging from 9 keV to 100 keV, accurate (LPS) and Gd 2 SiO 5 :Ce 3+ (GSO) non-proportional response curves were determined. By utilizing information from escape peaks in pulse height spectra the response curve can be extended down to several keV. A detailed study of the non-proportionality just above the K-edge is presented and from that a method, which we named K-dip spectroscopy, is obtained to reconstruct the electron response curve down to energies as low as 100 eV.

Nonproportional scintillation response of NaI:Tl to low energy x-ray photons and electrons

“…So-called escape-nPR curves will be shown. The method to estimate electron-nPR analogous to the one used by Collinson and Hill 17 and later by Wayne et al, 18 which we called K-dip spectroscopy, 19 is described in detail and used to reconstruct the so-called K-electron-nPR curve of NaI:Tl down to electron energies as low as 30 eV. A comparison of our data with the data of other authors is presented.…”

“…We have named such analysis K-dip spectroscopy. 19 The shape of the photopeak-nPR curve is similar to results reported before, 8 i.e., a linear increase from 111.2% to 115.8% with decrease in E X from 100 to 50 keV followed by a drop in the range 30-45 keV with a local minimum of 114.1% at 34.5 keV. Next the photopeak-nPR increases up to 117.2% at 20 keV followed by a steep decrease in the response with further decrease in E X .…”

“…Our strategy is to employ x-ray energies just above E KI . 19 The K-cascade response is assumed independent from the original x-ray energy. This response is found by tuning the x-ray energy very close above E KI , see inset Fig.…”

Improvement of γ-ray energy resolution of LaBr3:Ce3+ scintillation detectors by Sr2+ and Ca2+ co-doping

“…It is caused by a scintillator response that is not proportional to the amount of ionization energy deposited in the scintillator. 13,14 Figure 2 compares the response curves for NaI:Tl, 15 Lu 2 SiO 5 :Ce, 16 and LaBr 3 :5% Ce (Ref. 17) as has been determined with monochromatic synchrotron X-ray excitation.…”

“…We recently developed a method to obtain such a response down to very low electron energy of 100 eV. 16 By tuning the X-ray energy just above the K-shell electron binding energy E K of the most heavy element in the scintillator, a K-shell photoelectron will be ejected. The energy of this electron can be controlled within 10 eV accuracy simply by tuning the X-ray energy.…”