351 research outputs found
Hard x-ray broad band Laue lenses (80 - 600 keV): building methods and performances
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
Laue Lens Development for Hard X-rays (>60 keV)
Results of reflectivity measurements of mosaic crystal samples of Cu (111)
are reported. These tests were performed in the context of a feasibility study
of a hard X-ray focusing telescope for space astronomy with energy passband
from 60 to 600 keV. The technique envisaged is that of using mosaic crystals in
transmission configuration that diffract X-rays for Bragg diffraction (Laue
lens). The Laue lens assumed has a spherical shape with focal length . It is
made of flat mosaic crystal tiles suitably positioned in the lens. The samples
were grown and worked for this project at the Institute Laue-Langevin (ILL) in
Grenoble (France), while the reflectivity tests were performed at the X-ray
facility of the Physics Department of the University of Ferrara.Comment: 6 pages, 12 figures, accepted for publication in IEEE Transactions on
Nuclear Scienc
The OLYMPUS Internal Hydrogen Target
An internal hydrogen target system was developed for the OLYMPUS experiment
at DESY, in Hamburg, Germany. The target consisted of a long, thin-walled,
tubular cell within an aluminum scattering chamber. Hydrogen entered at the
center of the cell and exited through the ends, where it was removed from the
beamline by a multistage pumping system. A cryogenic coldhead cooled the target
cell to counteract heating from the beam and increase the density of hydrogen
in the target. A fixed collimator protected the cell from synchrotron radiation
and the beam halo. A series of wakefield suppressors reduced heating from beam
wakefields. The target system was installed within the DORIS storage ring and
was successfully operated during the course of the OLYMPUS experiment in 2012.
Information on the design, fabrication, and performance of the target system is
reported.Comment: 9 pages, 13 figure
Development status of the LAUE project
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 (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 photons/(cm s keV).Comment: 9 pages, 9 figures, presented at the Space Telescopes and
Instrumentation Symposium in Amsterdam, 2012: Ultraviolet to Gamma Ray
Conference. Published in the Proceedings of the SPIE, Volume 8443, id.
84430B-84430B-9 (2012
The LHCspin project
The LHCspin project aims to bring both unpolarized and polarized physics at the LHC through the installation of a gaseous fixed target at the upstream end of the LHCb detector. The forward geometry of the LHCb spectrometer (2 < η < 5) is perfectly suited for the reconstruction of particles produced in fixed-target collisions. The fixed-target configuration, with center-of-mass energies ranging from √sNN = 72 GeV in collisions with Pb beams to √s = 115 GeV in pp interactions, allows to cover a wide backward center-of-mass rapidity region, corresponding to the poorly explored high x-Bjorken and high x-Feynman regimes. The project has several ambitious goals regarding heavy-ion physics and new-era quantitative searches in QCD through the study of the nucleon's internal dynamics in terms of both quarks and gluons degrees of freedom. In particular, the use of transversely polarized H and D targets will allow to study the quarks TMDs in pp collisions at unique kinematic conditions. Furthermore, being LHCb specifically designed for heavy-flavor physics, final states with c- or b-quarks (e.g. inclusive quarkonia production) will be efficiently reconstructed, thus providing, among other fundamental measurememnts, access to the so-far unknown gluons TMDs. The status of the project is presented along with a selection of physics opportunities
Scientific prospects in soft gamma-ray astronomy enabled by the LAUE project
This paper summarizes the development of a successful project, LAUE,
supported by the Italian Space Agency (ASI) and devoted to the development of
long focal 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
photons cm s keV. We discuss a number of
open astrophysical questions that can settled with such an instrument aboard a
free-flying satellite.Comment: 17 pages, 18 figures, published in Proceedings of the SPIE, Volume
8861, id. 886106 17 pp. (2013
New results on focusing of gamma-rays with Laue lenses
We report on new results on the development activity of broad band Laue
lenses for hard X-/gamma-ray astronomy (70/100-600 keV). After the development
of a first prototype, whose performance was presented at the SPIE conference on
Astronomical Telescopes held last year in Marseille (Frontera et al. 2008), we
have improved the lens assembling technology. We present the development status
of the new lens prototype that is on the way to be assembled.Comment: 8 pages, 11 figures, to be Published in SPIE Proceedings,
vol.7437-19, 200
Development status of a Laue lens project for gamma-ray astronomy
We report the status of the HAXTEL project, devoted to perform a design study
and the development of a Laue lens prototype. After a summary of the major
results of the design study, the approach adopted to develop a Demonstration
Model of a Laue lens is discussed, the set up described, and some results
presented.Comment: 11 pages, 11 figures, 2007 SPIE Conference on Optics for EUV, X-Ray,
and Gamma-Ray Astronomy II
Exploring the Hard X-/soft gamma-ray Continuum Spectra with Laue Lenses
The history of X-ray astronomy has shown that any advancement in our
knowledge of the X-ray sky is strictly related to an increase in instrument
sensitivity. At energies above 60 keV, there are interesting prospects for
greatly improving the limiting sensitivity of the current generation of direct
viewing telescopes (with or without coded masks), offered by the use of Laue
lenses. We will discuss below the development status of a Hard X-Ray focusing
Telescope (HAXTEL) based on Laue lenses with a broad bandpass (from 60 to 600
keV) for the study of the X-ray continuum of celestial sources. We show two
examplesof multi-lens configurations with expected sensitivity orders of
magnitude better ( photons cm s keV
at 200 keV) than that achieved so far. With this unprecedented sensitivity,
very exciting astrophysical prospects are opened.Comment: 4 pages, 10 figures, to be published in the Proc. of the 39th ESLAB
Symosium, 19-21 April 200
Gamma-ray lens development status for a European Gamma-Ray Imager
A breakthrough in the sensitivity level of the hard X-/gamma-ray telescopes,
which today are based on detectors that view the sky through (or not) coded
masks, is expected when focusing optics will be available also in this energy
range. Focusing techniques are now in an advanced stage of development. To date
the most efficient technique to focus hard X-rays with energies above 100 keV
appears to be the Bragg diffraction from crystals in transmission configuration
(Laue lenses). Crystals with mosaic structure appear to be the most suitable to
build a Laue lens with a broad passband, even though other alternative
structures are being investigated. The goal of our project is the development
of a broad band focusing telescope based on gamma-ray lenses for the study of
the continuum emission of celestial sources from 60 keV up to >600 keV. We will
report details of our project, its development status and results of our
assessment study of a lens configuration for the European Gamma Ray Imager
(GRI) mission now under study for the ESA plan "Cosmic Vision 2015-2025".Comment: 12 pages, 12 figure
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