Gamma radiation can interact with borosilicate glass fibers primarily by producing ionization and electronic defects in the glass network. At very low doses (<50 rad, or <0.5 Gy), the effects are generally minimal, but a few points are worth noting:
Optical Properties
Radiation-induced color centers (defect sites that absorb light, causing darkening) are not significant at such a low dose.
Any induced absorption in the visible or near-IR spectrum would be below the detection threshold of standard optical methods.
Refractive index change is negligible.
Mechanical Properties
Tensile strength and elastic modulus of borosilicate glass fibers are unaffected at <50 rad.
Radiation damage becomes relevant only at much higher doses (10³–10⁶ rad range), where bond breakage and defect accumulation can alter fracture behavior.
Practical Implications
<50 rad is considered a low dose compared to typical environments where glass fibers are used (e.g., space radiation, nuclear reactors).
No long-term degradation or performance issues would be expected in borosilicate fibers exposed to such a dose.
Summary:
At gamma radiation doses below 50 rad, borosilicate glass fibers show no meaningful structural, optical, or mechanical changes. The dose is far below the threshold for detectable radiation-induced defects.