{'fraction_non_alphanumeric': 0.031578947368421054, 'fraction_numerical': 0.016374269005847954, 'mean_word_length': 4.594771241830065, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Optical properties of oxygen-deficiency related centers in amorphous SiO 2 investigated by synchrotron radiation

We report an investigation of the photoluminescence activity at 4.4 v eV in g -irradiated silica under UV and vacuum-UV excitation by synchrotron radiation. Our results evidence two iso-energetic contributions which can be related to two oxygen-deficient centers variants: ODC(I) and ODC(II). The first, excited within the 7.6 v eV absorption, is detected only at low temperature and has a lifetime of about 2 v ns. The second exhibits two excitation maxima peaked at 5.0 and 6.8 v eV, its amplitude decreases by a factor 2 on increasing the temperature whereas its lifetime has a value of about 4 v ns. These features give new insights on the excitation pathway of the 4.4 v eV emission involving the conversion from ODC(I) towards ODC(II).