A schematic diagram of the experimental setup showing the different elements used to excite luminescence of the sample, either ions (blue, from left side) or UV light (green, right side). The luminescence is measured by a very sensitive system composed of a scan filter monochromator (400–700 nm), and a photomultiplier.
Photography of the facility to measure IL at the CIEMAT laboratory.
The transmission properties of the low resolution spectral system are shown by the variation in the instrumental width (FWHM, left axis) and in the relative transmission (right axis).
The time evolution of the raw ionoluminescent signal during several seconds of irradiation of the phosphor screen. Several steps in the ion beam energy are seen. When the bias is set to zero between the different biasing values, the signal recovers the background value: (a) P45, (b) P46, (c) P47, (d) P47 (expanded view) (e) P56, and (f) TG-green.
A selection of plots corresponding to ionoluminescent spectra, in the range covered by the spectrometer, obtained at discrete energies of the ion beam (Ar) for representative phosphors: (a) P45, (b) P46, and (c) P56.
Influence of the ion beam current for three discrete energies of the ion beam (15, 25, and 33 keV) on (a) P45, (b) P47, and (c) YAG:Ce crystal. A clear saturation of the response is evident for current values above 35–40 mA.
Plot of the actual current measured at sample position vs the nominal current of the ion source provided by its own control system.
The IL response as a function of the proton beam energy for all the phosphor screens studied. A slight saturation effect is seen at the highest energy values, which is more pronounced for the case of the P47 screen.
Absolute IL response of P45 as a function of incident ion beam energy for three different ions (continuous lines) and theoretical estimates of the same, using a first approximation based on the SRIM code (dotted lines). Good correlation is seen for all ions at low energies .
Comparative response of (a) a powdered screen made of P45 phosphor and (b) a crystal scintillator YAG:Ce. The results correspond to luminescence data obtained with and ions and plotted in the same relative scale to highlight the excellent response of the phosphor screen compared with the scintillator in this low energy range.
Dependence of maximum transmission and FWHM of the filter monochromator as a function of wavelength.
List of materials prepared in-house (except TG-green) for IL measurements together with their most important properties.
A comparison of IL light production by irradiation (in absolute values) with normalized values for CL and PL for the materials under study. In the case of P45 its relative CL efficiency is high compared to the other materials. However, its relative IL efficiency is low. On the other hand, the relative response of P47 is higher for IL.
Estimated stopping ranges of accelerated argon, hydrogen and helium ions with 35 keV in the phosphors under study. For this, 10000 ions were used in the simulations.28
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