Publications (2)1.21 Total impact
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Article: POLARIX: a pathfinder mission of X-ray polarimetry
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ABSTRACT: Since the birth of X-ray astronomy, spectral, spatial and timing observation improved dramatically, procuring a wealth of information on the majority of the classes of the celestial sources. Polarimetry, instead, remained basically unprobed. X-ray polarimetry promises to provide additional information procuring two new observable quantities, the degree and the angle of polarization. POLARIX is a mission dedicated to X-ray polarimetry. It exploits the polarimetric response of a Gas Pixel Detector, combined with position sensitivity, that, at the focus of a telescope, results in a huge increase of sensitivity. Three Gas Pixel Detectors are coupled with three X-ray optics which are the heritage of JET-X mission. POLARIX will measure time resolved X-ray polarization with an angular resolution of about 20 arcsec in a field of view of 15 arcmin $\times$ 15 arcmin and with an energy resolution of 20 % at 6 keV. The Minimum Detectable Polarization is 12 % for a source having a flux of 1 mCrab and 10^5 s of observing time. The satellite will be placed in an equatorial orbit of 505 km of altitude by a Vega launcher.The telemetry down-link station will be Malindi. The pointing of POLARIX satellite will be gyroless and it will perform a double pointing during the earth occultation of one source, so maximizing the scientific return. POLARIX data are for 75 % open to the community while 25 % + SVP (Science Verification Phase, 1 month of operation) is dedicated to a core program activity open to the contribution of associated scientists. The planned duration of the mission is one year plus three months of commissioning and SVP, suitable to perform most of the basic science within the reach of this instrument.05/2011; -
Article: Threshold equalization algorithm for the XAA1.2 ASICs and its application to SuperAGILE X-ray imager
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ABSTRACT: In this paper we report the procedure developed and the results achieved for the equalization of threshold levels for the 6144 discriminator units of XAA1.2 ASICs chosen for the SuperAGILE X-ray imager onboard the AGILE satellite. For these kinds of imager, we will show that the threshold equalization is a critical issue. For each XAA1.2 we reduced the threshold dispersion by a factor of 3–4, and a factor of ∼2 for daisy chains of ASICs. Despite the method being developed for XAA1.2, the discriminator units and threshold fine-adjustment circuits are common to other chips of XA and VA-TA family, so that the algorithm and results can be extended to these two families of ASICs. This work may be useful for the design of electronic boards where the threshold equalization is a crucial issue.Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 593(3):367-375. · 1.21 Impact Factor
