  The radiation damage in optical materials mostly manifests itself as the loss
of optical transmittance. The optical materials recover from radiation damage
to some extent when the radiation exposure is stopped. The recovery is at a
faster rate in the presence of stimulating light. On the other hand, a
systematic study of the dynamics of the recovery as a function of the
stimulating light parameters such as its wavelength, intensity and exposure
duration and method has not been performed in detail yet. We established an LED
recovery station which provides pulsed and continuous light at various
wavelengths at custom geometries. We irradiated soda lime glass samples at a
rate of 87.5 Gy/min to a total dose of 3.5 kGy and 7.0 kGy. The optical
transmittance of the samples were then measured in 200 nm - 1500 nm range for
an extended period of time. The recovery from radiation damage is improved,
both in terms of timing and quantity, as the wavelength of the stimulating
light decreases. Around 50 % improvement was measured both in recovery rate and
the permanent damage when UV LED with a wavelength of 396 nm was used for
stimulation. The trend is such that wavelengths deeper in the UV range would
result in faster and more effective recovery from radiation damage. The LED
stimulated recovery technique from radiation damage is a feasible
implementation for the optical active media of radiation and particle detectors
which operate in high radiation environments.
