Radiation Hardness Study of Optical Glasses Using Electron Beam

The results of a series of radiation hardness tests on several commercially available optical glasses are presented. The irradiation was done at Microtron MT-25 of the Flerov Laboratory of Nuclear Reaction (FLNR) at Joint Institute for Nuclear Research (JINR) at Dubna by an electron beam with the energies of 5 MeV and 10 MeV for two series of tests. The total consumed dose up to 25 kGrey was deposited on the samples. The optical transmittance depending on the wave length of each sample was studied as a function of the total consumed dose. The changes in optical performance were tested using a spectrophotometer in a broad range of wavelengths from UV to low infrared spectra. The optical glasses with reasonable performance can be considered for the optical components of the future charged particle identification detectors based on the DIRC (Detection of Internally Reflected Cherenkov light) principle. The total consumed dose of 15 kGrey corresponds to the estimated 10 years of the DIRC detector workload at the ePIC experiment on the future Electron-Ion Collider (EIC) at Brookhaven National Laboratory (BNL, USA).