{'fraction_non_alphanumeric': 0.025089605734767026, 'fraction_numerical': 0.007168458781362007, 'mean_word_length': 4.973262032085562, '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}}
Thermal shaping of thin glass substrates for segmented grazing incidence active optics

In the context of the AHEAD project of the FP7 European call, a group of UK and Italian Institutions is proposing a research on X-ray optics that can provide large collecting areas (a few decades of m2) combined with a high angular resolution (0.1-1 arcsec). This requires the development of Active X-ray Optics in which the reflecting surfaces can be adjusted-manipulated in order to achieve and maintain the correct shape. In the context of an international collaboration with UK institutes, the Astronomical Observatory of Brera (INAF-OAB) is in charge of the production of thin (0.4 mm or less) glass mirror segments for the demonstration of a 2-reflection active X-ray system including piezoelectric actuators to improve the angular resolution, For the shell segments production the hot slumping approach of glass foils, already under investigation for the realization of IXO mirrors, is adopted. In this paper, a detailed description of the method is presented, reporting also on the metrological data of produced samples.