Optical properties and radiation hardness of Pr-doped sol-gel silica: Influence of fiber drawing process

Abstract

Optical properties and radiation hardness of Pr-doped sol-gel silica: Influence of fiber drawing process (2017) J. Lumin, vol. 192, p. 661-667 doi: 10.1016Lumin, vol. 192, p. 661-667 doi: 10. /j.jlumin.2017 Publisher's version of the article can be found at the following site: http://www.sciencedirect.com/science/article/pii/S0022231317307949 A complete and detailed characterization of the optical, scintillation and radiation hardness properties of Pr-doped silica is carried out employing different experimental techniques including steady-state and time-resolved photo-luminescence, radio-and thermo-luminescence, scintillation and optical absorption.Optical absorption measurements, performed after X-ray irradiation sequences up to 1 kGy, evidence the formation of radiation-induced absorption bands related to point defects acting as color centers. Spontaneous partial recovery of the radiation-induced defects at room temperature, as well as after thermal treatments, is also disclosed.Particular attention is paid to the comparison between bulk silica, both before and after a melting process, and fibers. The results reveal the presence of a lower concentration of optically active defects in melted glass. Such comparison highlights a role of the fiber drawing in modifying the glass defectiveness, consisting in the occurrence of a structural reorganization of the amorphous network during the process.

Needs, Trends, and Advances in Inorganic Scintillators

“…In the frame of the Intelum, project developments have been carried out to produce large volume of silica-doped fibers with cerium and praseodymium and to improve the optical properties in terms of scintillation and radiation hardness. It is possible to grow Pr and Ce silicadoped fibers at low cost of more than 20 m and a diameter from 200 to 600 μm with an attenuation length of more than 80 cm [162], [163].…”

Nanostructured Glass Composite for Self‐Calibrated Radiation Dose Rate Detection

“…The physical mechanisms underlying such phenomenon are associated with the interplay between defects and charge carriers, which can be named as hysteresis or “bright burn” in scintillators. [ 12–15 ] Under radiation exposure, a progressive filling of deep traps occurred, causing their neutralization as competitors with the luminescent recombination centers in free carrier capture. This phenomenon led to the increase in light yield during irradiation.…”

Recent Advances in Optical Fiber Enabled Radiation Sensors

“…To improve the radiation-capturing capability, detection length/accuracy, and robustness of devices, all-fiber RIL radiation fiber sensors were developed as intrinsic sensing (Figure 4d). Based on the development of the fiber thermal drawing process and material engineering, scintillating materials, such as rare earth element doped silica, Ce doped YAlO3, Ce doped Lu1.8Y2SiO3, etc., are inserted into the fiber cladding tube and drawn into scintillating fibers directly (Table 1) [62][63][64][65][66][67][68][69][70][71][72]. For the intrinsic RIL fiber sensor, the fiber not only transmits the generated photons, but also serves as the light emitting element that directly reacts with radiations.…”