Optical responses of a copper-activated sol-gel silica glass under low-dose and low-dose rate X-ray exposures

Cu/Ce-co-Doped Silica Glass as Radioluminescent Material for Ionizing Radiation Dosimetry

“…The RL signal of the Cu/Ce-co-doped glass, recorded using the PMT module is shown in Figure 5. When comparing the curves of this figure to the one related to a Cu + -doped rod [8], they all have the same general trend. However, it cannot be said that Ce 3+ ions have a beneficial role in the RL intensity level because we are not able to perform a quantitative comparison, as the setups may be slightly different in the two experiments.…”

“…In fact, the dissymmetrical shape of this emission spectra is well fitted to five Gaussian bands centered at 1.98 eV (626 nm; G1), 2.21 eV (561 nm; G2), 2.28 eV (543 nm; G3), 2.54 eV (488 nm; G4) and 2.75 eV (451 nm, G5) ( Figure 8a). The two bands peaking at 561 nm and 543 nm can be assigned to the emission from 3 Eg" levels of Cu + ions, i.e., from monovalent ions in octahedral symmetry with tetragonal distortion [8,19]. The bands at 488 nm and 451 nm are assigned to the transition from 5d to 4f states of Ce 3+ , the ground level 4f being split by spin-orbit interaction into sublevels 2 F 5/2 and 2 F 7/2 [7,26].…”

“…Both single Ce 3+ -and Cu + -activated silica glasses constitute promising candidates for ionizing radiation dosimetry with configurations that allow real-time and/or remote measurements [5,6]. Indeed, sol-gel-derived Ce 3+ -or Cu + -doped glasses excited by UV lasers or X-rays exhibit emission signals in blue and green regions, respectively [7,8]. Based on these optical activities and on the ability to control the size and shape of sol-gel samples, efficient copper or cerium-doped silica glasses were used as scintillators in distant dosimeters coupled with optical fibers.…”

“…Based on these optical activities and on the ability to control the size and shape of sol-gel samples, efficient copper or cerium-doped silica glasses were used as scintillators in distant dosimeters coupled with optical fibers. Those materials dedicated to dosimetry were sensitive to X-rays thanks to radioluminescence (RL) and 2 of 11 optically stimulated luminescence (OSL) processes [7][8][9][10]. Monovalent copper ion (Cu + ) is particularly interesting as a dopant for sol-gel silica because it exhibits strong luminescence quantum yields in the visible region if the xerogel is densified in neutral atmosphere [11].…”

“…Monovalent copper ion (Cu + ) is particularly interesting as a dopant for sol-gel silica because it exhibits strong luminescence quantum yields in the visible region if the xerogel is densified in neutral atmosphere [11]. In the case of copper-doped silica glasses, however, compared to cerium-doped ones, a darkening effect appeared after exposure to a dose level of 50 kGy(SiO 2 ), although the material remained X-ray-sensitive [8]. This effect is caused by the appearance of radio-induced colored centers, such as HC1, presenting visible absorption bands [12].…”