In the context of the Laue project devoted to build a Laue lens prototype for focusing celestial hard x-/soft gamma-rays, a Laue lens made of bent crystal tiles, with 20-m focal length, is simulated. The focusing energy passband is assumed to be 90 to 600 keV. The distortion of the image produced by the lens on the focal plane, due to effects of crystal tile misalignment and radial distortion of the crystal curvature, is investigated. The corresponding effective area of the lens, its point spread function, and sensitivity are calculated and compared with those exhibited by a nominal Laue lens with no misalignment and/or distortion. Such analysis is crucial to estimate the optical properties of a real lens, in which the investigated shortcomings could be present.
Parametric transducers may be used to monitor vibrational modes of resonant-mass Gravitational Wave (GW) detectors. This work focuses on the development and optimization of electromechanical transducers for the Brazilian GW detector "Mario Schenberg". We present the design and preliminary results for the optimization process of the last generation of the Schenberg parametric transduction system. Thanks to the results obtained from the last run of tests improvements for the transduction system will be planned and performed, in order to make the detector suitable for the searching of GW signals. The aim would be to obtain information about the direction and polarization of waves produced by astrophysical sources in the frequency bands of the spherical detector resonant modes.
We present the status of the LAUE project devoted to develop a technology for building a 20 meter long focal length Laue lens for hard X-/soft gamma-ray astronomy (80-600 keV). The Laue lens is composed of bent crystals of Gallium Arsenide (GaAs, 220) and Germanium (Ge, 111), and, for the first time, the focusing property of bent crystals has been exploited for this field of applications. We show the preliminary results concerning the adhesive employed to fix the crystal tiles over the lens support, the positioning accuracy obtained and possible further improvements. The Laue lens petal that will be completed in a few months has a pass band of 80-300 keV and is a fraction of an entire Laue lens capable of focusing x-rays up to 600 keV, possibly extendable down to ~20-30 keV with suitable low absorption crystal materials and focal length. The final goal is to develop a focusing optics that can improve the sensitivity over current telescopes in this energy band by 2 orders of magnitude.
For the first time, with the Laue project, bent crystals are being used for focusing photons in the 80-300 keV energy range. The advantage is their high reflectivity and better Point Spread Function with respect to the mosaic at crystals. Simulations have already shown their excellent focusing capability which makes them the best candidates for a Laue lens whose sensitivity is also driven by the size of the focused spot. Selected crystals are Germanium (perfect, (111)) and Gallium Arsenide (mosaic, (220)) with 40 m curvature radius to get a spherical lens with 20 m long focal length. A lens petal is being built. We report the measurement technique by which we are able to estimate the exact curvature of each tile within a few percent of uncertainty and their diffraction efficiency. We also discuss some results.
In the context of the LAUE project for focusing hard X-/gamma rays, a petal of the complete lens is being
assembled at the LARIX facility in the Department of Physics and Earth Science of the University of Ferrara.
The lens petal structure is composed of bent Germanium and Gallium Arsenide crystals in transmission geometry.
We present the expectations derived from a mathematical model of the lens petal. The extension of the model for
the complete LAUE project in the 90 – 600 keV energy range will be discussed as well. A quantitative analysis
of the results of these simulations is also presented.
We will describe the LAUE project, supported by the Italian Space Agency, whose aim is to demonstrate the capability to build a focusing optics in the hard X-/soft gamma-ray domain (80{600 keV). To show the lens feasibility, the assembling of a Laue lens petal prototype with 20 m focal length is ongoing. Indeed, a feasibility study, within the LAUE project, has demonstrated that a Laue lens made of petals is feasible. Our goal is a lens in the 80-600 keV energy band. In addition to a detailed description of the new LARIX facility, in which the lens is being assembled, we will report the results of the project obtained so far.
This paper summarizes the development of a successful project, LAUE, supported by the Italian Space Agency
(ASI) and devoted to the development of long foca length (up to 100—m) Laue lenses for hard X–/soft gamma–
ray astronomy (80-600 keV). The apparatus is ready and the assembling of a prototype lens petal is ongoing.
The great achievement of this project is the use of bent crystals. From measurements obtained on single crystals
and from simulations, we have estimated the expected Point Spread Function and thus the sensitivity of a lens
made of petals. The expected sensitivity is a few ×10−8 photons cm−2 s−1 keV−1). We discuss a number of open astrophysical questions that can settled with such an instrument aboard a free-flying satellite.
We present the status of LAUE, a project supported by the Italian Space Agency (ASI), and devoted to develop
Laue lenses with long focal length (from 10–15 meters up to 100 meters), for hard X–/soft gamma–ray astronomy
(80-600 keV). Thanks to their focusing capability, the design goal is to improve the sensitivity of the current
instrumention in the above energy band by 2 orders of magnitude, down to a few times 10−8 photons/(cm2 s keV).
In the context of the LAUE project devoted to build a long focal-length focusing optics for soft γ–ray astronomy (80 – 600 keV), we present the results of reflectivity measurements of bent crystals in different configurations, obtained by bending perfect or mosaic flat crystals. We also compare these results with those obtained using flat crystals. The measurements were performed using the Kα line of the Tungsten anode of the X–ray tube in the LARIX facility at the University of Ferrara. These results are finalized to select the best materials and to optimize the thickness of the crystal tiles that will be used for building a Laue lens petal which is a part of an entire Laue lens, with 20 m focal length and 100–300 keV passband. The final goal of the LAUE project is to overcome, by at least 2 orders of magnitude, the sensitivity limits of the current generation of γ–ray telescopes, and to improve the current γ–ray imaging capability.
In the context of the LAUE project devoted to build a long focal length focusing optics for soft gamma-ray
astronomy (70/100 keV to <>600 keV), we present results of simulation of a Laue lens, based on bent crystals in
different assembling configurations (quasi-mosaic and reflection-like geometries). The main aim is to significantly
overcome the sensitivity limits of the current generation of gamma-ray telescopes and improve the imaging
capability.
We present the results obtained with the new Laue lens prototype built in the LARIX facility in the Physics
Department of University of Ferrara. Following the results of the first prototype presented at the SPIE conference
in Marseille, and also thanks to the methods adopted for improving the prototype (SPIE conference in San Diego,
Ferrari et al. 2009) here we present the results of the new prototype with improved performances in terms of
point spread function (PSF) and spectral response.
We present the LAUE project devoted to develop an advanced technology for building a high focal length Laue
lens for soft gamma-ray astronomy (80-600 keV). The final goal is to develop a focusing optics that can improve
the current sensitivity in the above energy band by 2 orders of magnitude.
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