An Introduction to Radiation Effects on Optical Components and Fiber Optic Sensors

Optical Fibers and Optical Fiber Sensors Used in Radiation Monitoring

“…The RIA is affected by: 1. the manufacturing conditions, the parameters related to the technology used in producing the optical fiber: the deposition conditions, the draw process characteristicsdraw speed, fiber drawing tension, the preform deposition temperature, oxygen-toreagent ratio (02/R) used during core and clad deposition (Friebele, 1991;Girard et al, 2006;Hanafusa et al, 1986); 2. the existence, prior to the irradiation, of some precursors (Miniscalco et al, 1986); 3. the dopants present in the optical fiber core or cladding (pure silica, or doped with Ce, Er, Ge, F, N, P, Yb, high-OH, low-OH, high-Cl, low-Cl, H2-loading), (Arvidsson et al, 2009;Berghmans, 2006;Berghmans et al, 2008;Bisutti et al, 2007;Brichard & Fernandez Fernandez, 2005;Friebele, 1991;Girard et al, 2004a;Girard et al, 2004b;Girard et al, 2008;Griscom et al, 1996;Henschel et al, 1992;Kuyt et al, 2006;Lu et al, 1999;Mady et al, 2010;Paul et al, 2009;Regnier et al, 2007;Vedda et al, 2004;Wijnands et al, 2007), in some situations such ingredients contribute to the radiation hardening (Brichard et al, 2004;Brichard & Fernandez Fernandez, 2005;Girard et al, 2009); 4. the residual substances remaining after the manufacturing process, as for example chlorine having an associated color center in the UV spectral range, which can extend into the visible Girard & Marcandella, 2010); 5. the type of radiation to which the optical fiber is subjected (Arvidsson et al, 2009;Bisutti et al, 2007;Brichard et al, 2001;Calderón et al, 2006;Girard et al, 2004a;Girard et al, 2004b;…”

“…core-cladding dopants and diameter ratio (Deparis et al, 1997;Friebele, 1991;Girard et al, 2004a;Girard et al, 2004b;Kuhnhenn, 2005;Paul et al, 2009), and by the multitude of color centers activated under the irradiation process, such as (Brichard & Fernandez Fernandez, 2005;Origlio, 2009): 1. Ge centers: GeE', Ge(1), Ge(2), GEC, GeX, Ge-NBOH (Non-Bridging Oxygen Hole) (Alessi et al, 2010 ;Bisutti et al, 2007;Girard et al, 2006 ;Girard et al, 2008;Lu et al, 1999;Wijnands et al, 2007) ; 2. P centers: P1, P2, P4, Phosphorus-Oxygen-Hole -POHC (Bisutti et al, 2007;Girard et al, 2006;Girard et al, 2011 ;Paul et al, 2009;Wijnands et al, 2007) ; 3. silica related paramagnetic centers (Non-Bridging Oxygen Hole -NBOHC, PerOxyRadical -POR, SiE', Self-Trapped Hole -STH 1/2) or diamagnetic centres (Oxygen Deficient Centre -ODC; Peroxy Linkage -POL), Girard et al, 2008).…”

“…Ge centers: GeE', Ge(1), Ge(2), GEC, GeX, Ge-NBOH (Non-Bridging Oxygen Hole) (Alessi et al, 2010 ;Bisutti et al, 2007;Girard et al, 2006 ;Girard et al, 2008;Lu et al, 1999;Wijnands et al, 2007) ; 2. P centers: P1, P2, P4, Phosphorus-Oxygen-Hole -POHC (Bisutti et al, 2007;Girard et al, 2006;Girard et al, 2011 ;Paul et al, 2009;Wijnands et al, 2007) ; 3. silica related paramagnetic centers (Non-Bridging Oxygen Hole -NBOHC, PerOxyRadical -POR, SiE', Self-Trapped Hole -STH 1/2) or diamagnetic centres (Oxygen Deficient Centre -ODC; Peroxy Linkage -POL), Girard et al, 2008). In order to distinguish the contribution of various color centers to the irradiation induced absorption in silica optical fibers, complementary investigations, apart from the off-line/online optical transmission measurements, were carried-out: Electron Paramagnetic Resonance -EPR Radiation effects, 2007;Sporea et al, 2010a;Weeks & Sonder, 1963), luminescence (Girard et al, 2005;Girard et al, 2006;Sporea et al, 2010a;Miniscalco et al, 1986), thermoluminescence (Espinosa et al, 2006;Hashim et al, 2008;Mady et al, 2010;Sporea et al, 2010b;Yaakob et al, 2011), confocal microscopy luminescence and Raman analysis Origlio, 2009), time resolved photoluminescence .…”

Irradiation Effects in Optical Fibers

“…In the case of the optical fibers, the possibility to be incorporated into various types of sensors and actuators, free of additional hazards (i.e. fire, explosion), made them promising candidates to operate in adverse conditions as those required by space applications and terrestrial nuclear facilities Alam et al b , 2006;Berghmans et al, 2008;Ott, 2002). In nuclear environments optical fibers found an application niche in optical communication links, embedded into various all-fiber or hybrid sensors or as light-guides for control and diagnostics (Alfeeli et al, 2007;Ahrens et al, 2001;Fernando et al, 2005;Fielder et al, 2005;Florous et al, 2007;Gan et al 2008;Henschel et al, 2001;Kimurai et al 2002;O'Keeffe et al 2008;Reichle et al, 2007;Troska et al, 2003).…”

Features of the Fiber Optics Application in Iter

“…Предполагается, что за это время длитель-ность работы в D-T-режиме составит 4700 ч, или примерно 2•10 7 с. Из-за значительной длины оптово-локна в области радиационных полей (как минимум несколько метров) проблема падения его светопро-пускания в процессе эксплуатации может стать критичной [3,6], поэтому необходимо использовать оп-товолокно с высокой радиационной стойкостью. Очевидно, что для уменьшения радиационных нагрузок лучше всего размещать вход оптоволоконного коллектора как можно дальше от плазмы.…”