1：Experimental Design and Method Selection:

The study used the LabHC MOPERIX facility (160 kV X-ray tube with W-target) to expose the canonical OFs samples to steady state X-rays having an average energy of ~40 keV. The dose rate is adjusted by changing the distance between the samples and the source, while the dose is fixed by the selected irradiation run duration. Online RIA measurements consist in evaluating the transmitted light inside the fibers as a function of the irradiation time, defining the RIA as the additional transient losses of the fiber during the irradiation, normalized for the fiber length.

2：Sample Selection and Data Sources:

Four different canonical samples: PSC, Ge-, Al- and P-doped single mode optical fibers were investigated. Their main characteristics are listed in Table

3：List of Experimental Equipment and Materials:

Samples under test are connected to light sources (Ocean Optics DH-2000-BAL) and detectors (QE65000 spectrometer for the UV-Vis measurements and the NIR512 spectrometer for IR measurements, both from Ocean Optics).

4：Experimental Procedures and Operational Workflow:

The measured spectra have been acquired during the whole irradiation run with an integration time of ~1 s and an acquisition rate close to 1 Hz. For the measurements at LNT, the fibers under test were folded inside an isolated container filled with liquid nitrogen.

5：Data Analysis Methods:

The RIA spectral dependences of the different samples are reproduced using a set of well-known Gaussian bands associated with the different point defects associated to either pure silica and to the various dopants.