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F. Frontera,
E. Virgilli,
V. Liccardo,
V. Valsan,
V. Carassiti,
S. Chiozzi,
F. Evangelisti,
S. Squerzanti,
M. Statera,
V. Guidi, [......],
R. A. Zappettini,
E. Caroli,
N. Auricchio, S. Silvestri,
R. Camattari,
F. Cassese,
L. Recanatesi,
M. Pecora,
S. Mottini,
B. Negri
[show abstract]
[hide abstract]
ABSTRACT: 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 $10^{-8}$ photons/(cm$^2$ s keV).
11/2012;
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F. Frontera,
G. Loffredo,
A. Pisa,
L. Milani,
F. Nobili,
N. Auricchio,
V. Carassiti,
F. Evangelisti,
L. Landi,
S. Squerzanti,
K. H. Andersen,
P. Courtois,
L. Amati,
E. Caroli,
G. Landini, S. Silvestri,
J. B. Stephen,
J. M. Poulsen,
B. Negri,
G. Pareschi
[show abstract]
[hide abstract]
ABSTRACT: 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 III
12/2007;
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F. Frontera,
A. Pisa,
V. Carassiti,
F. Evangelisti,
G. Loffredo,
D. Pellicciotta,
K. H. Andersen,
P. Courtois,
L. Amati,
E. Caroli,
T. Franceschini,
G. Landini, S. Silvestri,
J. B. Stephen
[show abstract]
[hide abstract]
ABSTRACT: 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 figures
11/2006;
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[show abstract]
[hide abstract]
ABSTRACT: This paper describes the design of a star sensor based upon a high dynamic range CCD in order to reach an arcsec-level attitude
determination in balloon-borne missions. A custom star identification software was developed and laboratory-tested on a prototype
assembled using commercial components. A set of numerical simulations have been carried out to study the dependence on the
pointing precision of the centroid position accuracy, the number of detected stars and the effect of the image focusing. Moreover,
the role of the electronic noise and the discrete pixel structure on the light signals is identified by the analysis of numerical
simulations. Laboratory tests confirm that the arcsec pointing accuracy with a 1Hz update rate can be achieved with our combination
of custom-developed software and selected hardware components.
Experimental Astronomy 05/2006; 21(3):169-187. · 1.82 Impact Factor
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L. Amati,
F. Frontera,
N. Auricchio,
E. Caroli,
A. Basili,
A. Bogliolo,
G. Di Domenico,
T. Franceschini,
C. Guidorzi,
G. Landini,
N. Masetti,
E. Montanari,
M. Orlandini,
E. Palazzi, S. Silvestri,
J. B. Stephen,
G. Ventura
[show abstract]
[hide abstract]
ABSTRACT: Lobster-ISS is an X-ray all-sky monitor experiment selected by ESA two years ago for a Phase A study (now almost completed) for a future flight (2009) aboard the Columbus Exposed Payload Facility of the International Space Station. The main instrument, based on MCP optics with Lobster-eye geometry, has an energy passband from 0.1 to 3.5 keV, an unprecedented daily sensitivity of 2x10^{-12} erg cm^{-2}s$^{-1}, and it is capable to scan, during each orbit, the entire sky with an angular resolution of 4--6 arcmin. This X-ray telescope is flanked by a Gamma Ray Burst Monitor, with the minimum requirement of recognizing true GRBs from other transient events. In this paper we describe the GRBM. In addition to the minimum requirement, the instrument proposed is capable to roughly localize GRBs which occur in the Lobster FOV (162x22.5 degrees) and to significantly extend the scientific capabilities of the main instrument for the study of GRBs and X-ray transients. The combination of the two instruments will allow an unprecedented spectral coverage (from 0.1 up to 300/700 keV) for a sensitive study of the GRB prompt emission in the passband where GRBs and X-Ray Flashes emit most of their energy. The low-energy spectral band (0.1-10 keV) is of key importance for the study of the GRB environment and the search of transient absorption and emission features from GRBs, both goals being crucial for unveiling the GRB phenomenon. The entire energy band of Lobster-ISS is not covered by either the Swift satellite or other GRB missions foreseen in the next decade. Comment: 6 pages, 4 figures. Paper presented at the COSPAR 2004 General Assembly (Paris), accepted for publication in Advances in Space Research in June 2005 and available on-line at the Journal site (http://www.sciencedirect.com/science/journal/02731177), section "Articles in press"
05/2006;
-
NEXT GENERATION OF SCIENTIFIC BALLOON MISSIONS; 01/2006 · 1.18 Impact Factor
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F. Frontera,
A. Pisa,
G. Loffredo,
D. Pellicciotta,
V. Carassiti,
F. Evangelisti,
K. Andersen,
P. Courtois,
L. Amati,
E. Caroli,
T. Franceschini,
G. Landini, S. Silvestri,
J. Stephen
[show abstract]
[hide abstract]
ABSTRACT: A review of the HAXTEL project devoted to the development of a Laue lens telescope for hard X-/gamma-ray observation of the
continuum spectra of celestial sources is presented. Main design properties, open issues, the status of the project and an
example of multi-lens configuration with sensitivity expectations are discussed.
12/2005: pages 241-251;
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A. Pisa,
F. Frontera,
P. De Chiara,
G. Loffredo,
D. Pellicciotta,
G. Landini,
T. Franceschini, S. Silvestri,
K. Andersen,
P. Courtois,
B. Hamelin
[show abstract]
[hide abstract]
ABSTRACT: We report on the feasibility study of a Laue lens for hard X-rays (>60
keV)based on mosaic crystals, for astrophysical applications. In particular we
discuss the scientific motivations, its functioning principle, the procedure
followed to select the suitable crystal materials, the criteria adopted to
establish crystal dimensions and their distribution on the lens in order to
obtain the best lens focusing capabilities, and the criteria for optimizing the
lens effective area in a given passband. We also discuss the effects of
misalignments of the crystal tiles due to unavoidable mechanical errors in
assembling the lens. A software was developed to face all these topics and to
evaluate the expected lens performance.
11/2004;
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G Pareschi,
G Di Cocco,
E Caroli,
O Citterio,
V Cotroneo,
S Del Sordo,
F Frontera,
L Gizzi,
G Malaguti, S Silvestri,
D Spiga,
HEXIT Collaboration
16TH ESA SYMPOSIUM ON EUROPEAN ROCKET AND BALLOON PROGRAMMES AND RELATED RESEARCH, PROCEEDINGS; 01/2003
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PROCEEDINGS OF THE 9TH GIFCO CONFERENCE WHAT ARE THE PROSPECTS FOR COSMIC PHYSICS IN ITALY?; 01/2000
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[show abstract]
[hide abstract]
ABSTRACT: Hard X-ray (>15 keV) experiments for space astronomy require a
detailed energy calibration in order to determine their true response
matrix. To this end, an X-ray facility is built based on the use of a
very stable X-ray generator plus an X-ray goniometer for crystal
diffraction, that can provide collimated and monochromatic photons with
energies in the range from about 15 keV to about 140 keV. A description
is presented of the facility and its performance. The facility is used
to test samples of hard X-ray mirrors for space astronomy, and it is
being equipped to calibrate the high-energy experiment PDS on board the
X-ray astronomy satellite SAX
IEEE Transactions on Nuclear Science 09/1993; · 1.45 Impact Factor
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F. Frontera,
D. Dal Fiume,
M. Pamini,
J. M. Poulsen,
C. M. Zhang,
A. Basili,
T. Franceschini,
G. Landini, S. Silvestri,
E. Costa,
A. Emanuele,
A. Rubini
[show abstract]
[hide abstract]
ABSTRACT: The Phoswich Detection System (PDS) is one of the four narrow-field instruments on board the SAX satellite. The experiment
will be dedicated to temporal and spectral studies of celestial X-ray sources in the 15÷300 keV energy band. The PDS detector
is composed of 4 actively shielded NaI(TI)/CsI(Na) phoswich scintillators and has a field of view of 1.4o (FWHM). The total geometric area is 800 cm2. The instrument is designed with the goal to achieve an energy resolution better than 17% at 60 keV and a 3σ flux sensitivity
for an observation time of 105 s of about 1×10−6 photons cm−2 s−1 in an energy band 40 keV wide centred at 100 keV. This sensitivity corresponds to about 2 milliCrab flux units in the same
energy range. The expected 3σ sensitivity of the PDS to cyclotron emission lines is about 3×10−5 photons cm−2 s−1 at 60 keV in 105 s. The CsI(Na) lateral shields of the PDS will also be used as a gamma-ray burst monitor. In this report we give a detailed
description of the experiment design and we discuss the expected in-flight performances of the PDS.
Nuovo Cimento- Societa Italiana di Fisica Sezione C 08/1992; 15(5):867-878. · 0.35 Impact Factor
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D. Cardini,
J. M. Poulsen,
E. Costa,
D. dal Fiume,
A. Emanuele,
F. Frontera,
A. Basili,
T. Franceschini,
M. Frutti,
G. Landini, S. Silvestri
[show abstract]
[hide abstract]
ABSTRACT: A hard X-ray (20-300 keV) Fourier-Bessel imaging telescope devoted to
observations of celestial X-ray sources from stratospheric balloons is
described. The imaging capabilities are obtained by the use of 16
rotating modulation collimators, each with different pitch angle,
mounted above the field collimators of the large area hard X-ray
experiment LAPEX. The detection plane of this experiment is made of 16
NaI(Tl)/CsI(Na) phoswich detectors. The theory of the Fourier-Bessel
transform image is reviewed and the optical properties of our imaging
device are determined. Also, the effects of the gondola azimuth
instability are studied. The expected angular resolution of the
telescope is 22 arcmin. Its expected 3 sigma sensitivity in the 20-200
keV energy band corresponds to 10 mCrab for an on-axis source observed
for 10,000 s at a residual atmospheric depth of 3 g/sq cm.
Astronomy and Astrophysics 03/1992; 257:824-830. · 4.59 Impact Factor
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F. Frontera,
A. Basili,
D. Dal Fiume,
T. Franceschini,
G. Landini,
E. Morelli,
J. M. Poulsen, S. Silvestri,
E. Costa,
D. Cardini,
A. Emanuele,
A. Rubini
[show abstract]
[hide abstract]
ABSTRACT: The LAPEX payload is described in the configuration that will be launched to observe the supernova SN 1987A. The balloon flight
will be performed from Alice Springs (Australia) in April 1989 as a part of a NASA balloon campaign. The experiment will allow
simultaneous observations of source and background in order to minimize systematic errors due to background variations. The
limiting flux sensitivity of the instrument in the (20÷200) keV energy band is 4·10−6 ph/(cm2s keV) or ∼2.5 mCrab for a 104 s observation of SN 1987A. The presence of a57Co emission line in the SN 1987A photon spectrum could be detected down to an intensity level of ∼8·10−5 photons/cm2s as at 99.7% confidence level. The high resolution of the event timing (<0.1 ms) will make it possible to detect millisecond
pulsations with amplitudes down to ∼4% of the expected average flux from SN 1987A in the (20÷60) keV band.
Viene descritto l'esperimento LAPEX nella configurazione che sarà lanciata per osservare la supernova SN 1987A. Il lancio
di pallone sarà effettuato da Alice Springs (Australia) nell'aprile 1989 nell'ambito di una campagna di palloni organizzata
dalla NASA. L'esperimento consentirà l'osservazione simultanea della sorgente e del fondo ambientale per minimizzare gli errori
sistematici dovuti a variazioni di fondo. La sensibilità limite dello strumento nella banda di energia (20÷200) keV è 4·10−6 fotoni/(cm2s keV) equivalenti a 2.5 mCrab per una osservazione di SN 1987A di durata 104s. La presenza di una possibile riga in emissione di57Co nello spettro di fotoni di SN 1987A potrà essere rivelata a un livello di 8·10−5 fotoni/(cm2s) a un grado di fiducia del 99.7%. L'elevata risoluzione temporale nel marcare gli eventi (<0.1 ms) consentirà la rivelazione
di possibili pulsazioni di periodo attorno al millisecondo con ampiezza fino a 4% del flusso medio atteso da SN 1987A nella
banda di energia (20÷60) keV.
Описывается научная аппарптура LAPEX, которая будет запущена для наблюдения сверхновой SN1987a. Полет аэростата будет осуществлен
из Австралии в апреле 1989 г., как часть программы HACA. Эксперимент позволит одновременно наблюдать источник и фон, чтобы
минимизировать систематические погрешности, обусловленные изменениями фона. Предельная чувствительность аппаратуры в энергетической
области (20÷200) кэВ составляет 4·10−6 фот/см2.с.кэВ или ∼2,5 mCrab для 104 с наблюдения SN1987 A. Наличие линии излучения57Co в фотонном спектре SN1987 A может позволить детектировать интенсивность вплоть до ∼8·10−5 фотонов/см2 с с 99,7% достоверностью. Высокое разрецение времени событий (<0.1 мс) позволит детектировать миллесекундные пульсации с
амплитудами вплоть до ∼4% для ожидаемого среднего потока от SN1987 A в области (20÷60) кэВ.
Nuovo Cimento- Societa Italiana di Fisica Sezione C 02/1990; 13(2):437-444. · 0.35 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: Satellite and balloon observations have shown that several classes of celestial objects are hard ( 15 keV) energy band with a sensitivity of approx 10 mCrab has been performed with the UCSD/MIT instrument (A4) on board the HEAO 1 satellite. About 70 X-ray sources were detected, including galactic and extragalactic objects. Hard X-ray emission has been detected in the Galaxy from X-ray pulsars. Extragalactic sources of hard X-ray emission include clusters of galaxies, QSOs, BL Lac objects, Seyfert galaxies. The essential characteristics of the Large Area Phoswich Experiment (LAPEX) for crowded sky field observations are described. It has: (1) a broad energy band of operation (20-300 keV); (2) a 3 sigma sensitivity of about 1 mCrab in 10,000 s of live observing time; and (3) imaging capabilities with an angular resolution of about 20'.
09/1985;
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F. Frontera,
D. Dal Fiume,
T. Franceschini,
G. Landini,
E. Morelli,
M. Pamini,
A. Rubini, S. Silvestri,
G. Spada,
E. Costa,
D. Cardini,
A. Emanuele
[show abstract]
[hide abstract]
ABSTRACT: We describe a balloon experiment, currently in the marking, devoted to the observation of celestial X-ray sources. The main
features of the X-ray telescope are summarized as follows. It operates in the energy band from 20 to 300 keV. Its energy resolution
is about 17% at 60 keV. Under the hypothesis of 104 s of observing time, 3 mbar of residual atmospheric pressure and 3σ of statistical significance, the expected sensitivity
of the instrument is 2·10−6 photons/cm2 s keV in the (20÷200) keV energy band, corresponding to about 1 milliCrab. Its high sensitivity allows us to detect both
time variability in the flux and cyclotron lines in the spectra of X-ray sources. It has a field of view of 3° FWHM and has
the possibility of resolving complex fields by using multipitch modulation collimators. With such a configuration its angular
resolution is about 10′.
Si descrive un esperimento ad alta sensibilità per l'osservazione di sorgenti celesti di raggi X da quote raggiungibili con
palloni stratosferici. Le caratteristiche principali dello strumento sono le seguenti. Banda di lavoro: (20÷300) keV. Risoluzione
nenergetica: 17% a 60 keV. Sensibilità (3σ) in 104 s di osservazione di una sorgente alla quota di circa 3 mbar: 2·10−6 fotoni/cm2 s keV nella banda (20÷200) keV, corrispondente a circa 1/1000 del flusso della Crab Nebula nella stessa banda. Sensibilità
a righe di ciclotrone nello spettro di sorgenti X: 1/20 della intensità della riga trovata in Her X-1. Il telescopio ha un
campo di vista di 3° FWHM con un sistema di monitoraggio continuo del fondo strumentale e della sorgente sotto osservazione.
Per alcuni obiettivi è previsto l'impiego di una matrice di collimatori a modulazione, il che consentirà una risoluzione spaziale
di circa 10′.
Мы описываем эксперимент на шарах-зондах для наблюдения небесных рентгеновских источнков. Приводятся основные характеристики
рентгеновского телескопа. Телеслоп действует в области энергий от 20 до 300 кэВ. Энергетическое разрешение составляет около
17% при 60 кэВ. Ожидаемая чувствительность (3σ) при времени наблюдения 104 с и величине остаточного атмосферного давления 3 мбар составит 2·10−6 фотонов/см2 с кэВ в энергетической области (20÷200) кэВ, что соответствует 1/1000 потока от Крабовидной туманности в той же энергергетической
области. Высокая чувствительность позволяет детекировать временные изменения потока и циклотронных линий в спектрах рентгеновоких
источников. Телескоп имеет поле видимости 3° FMHM и имеет возможность разрешения составных полей. С помощью указанной конфигурации
телескопа его угловое разрешение составляет около 10 минут.
Nuovo Cimento- Societa Italiana di Fisica Sezione C 10/1984; 7(6):656-672. · 0.35 Impact Factor
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F. Frontera,
D. Dal Fiume,
M. Pamini,
J.M. Poulsen,
A. Basili,
T. Franceschini,
G. Landini, S. Silvestri,
E. Costa,
D. Cardini,
A. Emanuele,
A. Rubini
[show abstract]
[hide abstract]
ABSTRACT: The high energy X-ray experiment PDS (Phoswich Detection System) is one of the four narrow field instruments on board the SAX satellite. The experiment will be dedicated to temporal and spectral studies of celestial X-ray sources in the 15–300 keV energy band. The PDS detector is composed of 4 actively shielded NaI(Tl)/CsI(Na) phoswich scintillators with a field of view of 1°.4 (FWHM). The total geometric area is 800 cm2. The design of the instrument is made with the goal to achieve an energy resolution better than 17% at 60 keV and a 3 σ flux sensitivity for an observation time of 105 s of about 2 milliCrab in one energy band 40 keV wide centered at 100 keV. The expected 3 σ sensitivity of the PDS to cyclotron lines is about 5×10−5 photons/cm2 s at 60 keV in 105 s. The CsI(Na) lateral shields of the PDS will also be utilized as a gamma-ray burst monitor. Details of the experiment design are described and expected performance is given.
Advances in Space Research.
-
[show abstract]
[hide abstract]
ABSTRACT: Four different phoswich units were included in a modular hard X-ray balloon experiment launched on August 10, 1982 in order to check the dependence of background level and rejection efficiency of NaI(Tl)/CsI(Na) phoswich detectors on scintillator thicknesses. The results concern the dependence of the background intensity on both the thickness of the active shield, for a fixed primary detector thickness, and on the thickness of the primary detector, given the active shield thickness. A direct comparison of phoswich detectors with passively shielded NaI(Tl) crystals is also given. As a consequence practical hints for designing new phoswich detectors are derived and the limiting sensitivity of these detectors for hard X-ray observations of celestial sources is inferred.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment.
-
L. Amati,
F. Frontera,
N. Auricchio,
E. Caroli,
A. Basili,
A. Bogliolo,
G. Di Domenico,
T. Franceschini,
C. Guidorzi,
G. Landini,
N. Masetti,
E. Montanari,
M. Orlandini,
E. Palazzi, S. Silvestri,
J.B. Stephen,
G. Ventura
[show abstract]
[hide abstract]
ABSTRACT: Lobster-ISS is an X-ray all-sky monitor experiment selected by ESA two years ago for a Phase A study (now almost completed) for a future flight (2009) aboard the Columbus Exposed Payload Facility of the International Space Station. The main instrument, based on MCP optics with Lobster-eye geometry, has an energy passband from 0.1 to 3.5 keV, an unprecedented daily sensitivity of 2 × 10−12 erg cm−2 s−1, and it is capable to scan, during each orbit, the entire sky with an angular resolution of 4–6′. This X-ray telescope is flanked by a Gamma Ray Burst Monitor, with the minimum requirement of recognizing true GRBs from other transient events. In this paper we describe the GRBM. In addition to the minimum requirement, the instrument proposed is capable to roughly localize GRBs which occur in the Lobster FOV (162 × 22.5°) and to significantly extend the scientific capabilities of the main instrument for the study of GRBs and X-ray transients. The combination of the two instruments will allow an unprecedented spectral coverage (from 0.1 up to 300/700 keV) for a sensitive study of the GRB prompt emission in the passband where GRBs and X-Ray Flashes emit most of their energy. The low-energy spectral band (0.1–10 keV) is of key importance for the study of the GRB environment and the search of transient absorption and emission features from GRBs, both goals being crucial for unveiling the GRB phenomenon. The entire energy band of Lobster-ISS is not covered by either the Swift satellite or other GRB missions foreseen in the next decade.
Advances in Space Research.
-
[show abstract]
[hide abstract]
ABSTRACT: A simple high performance pulse shape analyzer has been developed for the astronomical hard X-ray (20–300 keV) experiment LAPEX. The telescope makes use of 16 phoswich detectors of NaI(Tl)/CsI(Na) scintillator crystals. The pulse shape analyzer is based on 16 pairs of shaping amplifiers — one pair for each detector — and one digital electronic chain for calculation of an amplitude ratio, the pulse shape parameter. We describe the mathematical basis of the pulse shape analyser and the functions of its main circuit blocks. Both laboratory and in-flight data demonstrating the good performance of the circuits are presented.
Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 324(3):589-597. · 1.21 Impact Factor
