A new technology of Laue lenses assembling for Astrophysics observations.

Virgilli E., Auricchio N., Caroli E., Ferrari C., Frontera F., Rosati P., Stephen J.B.
  Venerdì 30/09   15:00 - 18:00   Edificio Psicologia 2 - Aula 2E   III - Astrofisica
The role of hard-X-ray astronomy ($> 10$ keV) is widely recognized thanks to the numerous results obtained with the most recent satellite missions on many classes of X-ray celestial sources. These results have demonstrated the importance of the high ($> 60$) energy band, in which the statistical quality of the measurements can be increased up to two order of magnitude by using Laue lenses to study the high-energy celestial sources with the same detail which was achieved at lower energies ($< 80$ keV), at which focusing optics are available since a long time. We describe new results of the measurement of the focusing effect from diffractive bent crystals made of Gallium Arsenide (GaAs) that can be successfully used for the construction of broad-band Laue lens that can extend the energy band far beyond the 80 keV limit for actual multilayer with limited focal length ($< 20$ m) and weight. We will report on a new technology we have developed for assembling a Laue lens. This lens is made of bent crystals of gallium arsenide (GaAs, 220) with a focal length of 20 m for space applications. Thanks to the bent crystal the Pont Spread Function (PSF) of the lens is very thin with an angular spread at Full Width at Half Maximum (FWHM) of about 20 arcsecs for paraxial photons. In order to achieve this PSF it is crucial to glue the crystals to the lens frame in such way that the resin polymerization does not influence the initial position of the crystals. In this paper we will present the last results of a promising bent tiles gluing technologies over a mechanical support with the same curvature adopted for achieving our final assembling goal.