The Wide Field Imager of the International X-ray Observatory

Max-Planck-Institut Halbleiterlabor, Otto-Hahn-Ring 6, 81739 München, Germany; Johannes Gutenberg-Universität, Inst. f. anorganische und analytische Chemie, 55099 Mainz, Germany; Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139-4307, USA; Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802, USA; Politecnico di Milano, Dipartimento di Elettronica e Informazione, Milano, Italy; INFN Sezione di Milano, Milano, Italy; Space Research Centre, Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH, UK; PNSensor GmbH, Römerstr. 28, 80803 München, Germany; Max-Planck-Institut für extraterrestrische Physik, Giessenbachstr., 85748 Garching, Germany; Technische Universität Darmstadt, Institut für Kernphysik, Schlossgartenstr. 9, 64289 Darmstadt, Germany; Max-Planck-Institut für Physik, Föhringer Ring 6, 80805 München, Germany; Harvard/Smithsonian Center for Astrophysics, 60 Garden Street, MS-67, Cambridge, MA 02138, USA; Institut für Astronomie und Astrophysik, Sand 1, 72076 Tübingen, Germany; Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Str. 2, 37191 Katlenburg-Lindau, Germany; Department of Earth and Space Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan; Dr. Karl Remeis-Sternwarte, Astronom. Inst. d. Univ. Erlangen-Nürnberg, Sternwartstr. 7, 96049 Bamberg, Germany; Erlangen Center for Astroparticle Physics (ECAP), Erwin-Rommel-Str. 1, 91058 Erlangen, Germany
Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment (Impact Factor: 1.14). 12/2010; DOI: 10.1016/j.nima.2010.05.049
Source: OAI

ABSTRACT The International X-ray Observatory (IXO) will be a joint X-ray observatory mission by ESA, NASA and JAXA. It will have a large effective area (3 m2 at 1.25 keV) grazing incidence mirror system with good angular resolution (5 arcsec at 0.1–10 keV) and will feature a comprehensive suite of scientific instruments: an X-ray Microcalorimeter Spectrometer, a High Time Resolution Spectrometer, an X-ray Polarimeter, an X-ray Grating Spectrometer, a Hard X-ray Imager and a Wide-Field Imager.The Wide Field Imager (WFI) has a field-of-view of 18 ft×18 ft. It will be sensitive between 0.1 and 15 keV, offer the full angular resolution of the mirrors and good energy resolution. The WFI will be implemented as a 6 in. wafer-scale monolithical array of 1024×1024 pixels of size. The DEpleted P-channel Field-Effect Transistors (DEPFET) forming the individual pixels are devices combining the functionalities of both detector and amplifier. Signal electrons are collected in a potential well below the transistor's gate, modulating the transistor current. Even when the device is powered off, the signal charge is collected and kept in the potential well below the gate until it is explicitly cleared. This makes flexible and fast readout modes possible.

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    ABSTRACT: The ROOT based Offline and Online Analysis (ROAn) framework was developed to perform data analysis on data from Depleted P-channel Field Effect Transistor (DePFET) detectors, a type of active pixel sensors developed at the MPI Halbleiterlabor (HLL). ROAn is highly flexible and extensible, thanks to ROOT's features like run-time type information and reflection. ROAn provides an analysis program which allows to perform configurable step-by-step analysis on arbitrary data, an associated suite of algorithms focused on DePFET data analysis, and a viewer program for displaying and processing online or offline detector data streams. The analysis program encapsulates the applied algorithms in objects called steps which produce analysis results. The dependency between results and thus the order of calculation is resolved automatically by the program. To optimize algorithms for studying detector effects, analysis parameters are often changed. Such changes of input parameters are detected in subsequent analysis runs and only the necessary recalculations are triggered. This saves time and simultaneously keeps the results consistent. The viewer program offers a configurable Graphical User Interface (GUI) and process chain, which allows the user to adapt the program to different tasks such as offline viewing of file data, online monitoring of running detector systems, or performing online data analysis (histogramming, calibration, etc.). Because of its modular design, ROAn can be extended easily, e.g. be adapted to new detector types and analysis processes.
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    ABSTRACT: The development of multi-layer optics which allow to focus photons up to 100 keV and more promises an enormous jump in sensitivity in the hard X-ray energy band. This technology is already planned to be exploited by future missions dedicated to spectroscopy and imaging at energies >10 keV, e.g. Astro-H and NuSTAR. Nevertheless, our understanding of the hard X-ray sky would greatly benefit from carrying out contemporaneous polarimetric measurements, because the study of hard spectral tails and of polarized emission often are two complementary diagnostics of the same non-thermal and acceleration processes. At energies above a few tens of keV, the preferred technique to detect polarization involves the determination of photon directions after a Compton scattering. Many authors have asserted that stacked detectors with imaging capabilities can be exploited for this purpose. If it is possible to discriminate those events which initially interact in the first detector by Compton scattering and are subsequently absorbed by the second layer, the direction of scattering is singled out from the hit pixels in the two detectors. In this paper we give the first detailed discussion of the sensitivity of such a generic design to the X-ray polarization. The efficiency and the modulation factor are calculated analytically from the geometry of the instruments and then compared with the performance as derived by means of Geant4 Monte Carlo simulations.
    The Astrophysical Journal 04/2012; 751(2). · 6.73 Impact Factor
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    ABSTRACT: This report reviews current trends in the R&D of semiconductor pixellated sensors for vertex tracking and radiation imaging. It identifies requirements of future HEP experiments at colliders, needed technological breakthroughs and highlights the relation to radiation detection and imaging applications in other fields of science.
    Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 08/2012; 716. · 1.14 Impact Factor

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