Investigation of radiation response on pure silica large core fibers at low dose levels.

The radiation responses of three large core silica fibers with low OH contents were investigated with a high Dose rate (105 Gy/s), low total dose (1 mGy) pulsed X-rays, and low Dose rate (0.054 Gy/s) steady state gamma rays, respectively, to develop a fast radiation detector based on silica fiber and scintillator. The radiation-induced emission (RIE) and radiation-induced attenuation (RIA) of these fibers from a 350 nm–550 nm spectrum range were evaluated. All of them presented low RIA levels, and the Cherenkov radiation and individual peak fluorescence emission centered at 460 nm, being the primary contributors to RIE. In addition, the spectral decomposition of RIAs is performed using known Gaussian absorption bands associated with a few point defects; such as Si-related defects (Non-bridging-oxygen hole center-NBOHC, Si-ODC(II) Self-trapped hole-STH), and chlorine related defects (Cl0 and Cl 2). The performances of these point defects at various irradiation doses are analyzed. [ABSTRACT FROM AUTHOR]