[en] The Wide Field Imager (WFI) is one of the two instruments of the ATHENA astrophysics space mission approved by ESA as the second large mission in the Cosmic Vision 2015-2025 Science Programme. The WFI, based on a large array of depleted field effect transistors (DEPFET), will provide imaging in the 0.2-15 keV band over a 40'x40' field of view, simultaneously with spectrally and time resolved photon counting. The WFI detector is also sensitive to UV/Vis photons, with an electron-hole pair production efficiency in the UV/VIS larger than that for X-ray photons. Optically generated photo-electrons may degrade the spectral resolution as well as change the energy scale by introducing a signal offset. For this reason, the use of X-ray transparent optical blocking filters (OBFs) are needed to allow the observation of X-ray sources that present a UV/Vis bright counterpart. The OBFs design is challenging since one of the two required filters is quite large ( 160 mm × 160 mm), very thin (< 200 nm), and shall survive the mechanical load during the launch. In this paper, we review the main results of modeling and characterization tests of OBF partially representative samples, performed during the phase A study, to identify the suitable materials, optimize the design, prove that the filters can be launched in atmospheric pressure, and thus demonstrate that the chosen technology can reach the proper technical readiness before mission adoption.
Research center :
STAR - Space sciences, Technologies and Astrophysics Research - ULiège
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Barbera, Marco; Univ. degli Studi di Palermo (Italy)
Lo Cicero, Ugo; INAF - Osservatorio Astronomico di Palermo Giuseppe S. Vaiana (Italy)
Sciortino, Luisa; Univ. degli studi di Palermo (Italy)
D'Anca, Fabio; Consiglio Nazionale delle Ricerche (Italy)
Parodi, Giancarlo; BCV Progetti S.r.l. (Italy)
Rataj, Miroslaw; Space Research Ctr. Polish Acadmey of Sciences (Poland)
Polak, Szymon; Space Research Ctr. Polish Acadmey of Sciences (Poland)
Pilch, Adam; AGH Univ. of Science and Technology (Poland)
Meidinger, Norbert; Max-Planck-Institut für extraterrestrische Physik (Germany)
Sciortino, Salvatore; INAF - Istituto di Astrofisica e Planetologia Spaziali (Italy)
Rauw, Grégor ; Université de Liège - ULiège > Groupe d'astrophysique des hautes énergies (GAPHE)
Branduardi Raymont, Graziella; Univ. College London (United Kingdom)
Mineo, Teresa; INAF - Istituto di Astrofisica e Planetologia Spaziali (Italy)
Perinati, Emanuele; Eberhard Karls Univ. Tübingen (Germany)
Giglio, Paolo; Univ. degli Studi di Palermo (Italy)
Collura, Alfonso; INAF - Osservatorio Astronomico di Palermo (Italy)
Varisco, Salvatore; INAF - Osservatorio Astronomico di Palermo (Italy)
Candia, Roberto; INAF - Osservatorio Astronomico di Palermo (Italy))
Barcons, X., et al., "Athena: the X-ray observatory to study the hot and energetic Universe", Journal of Physics Conference Series, Volume 610, Issue 1, (2015). doi:10. 1088/1742-6596/610/1/012008
Nandra, K., et al., "The Hot and Energetic Universe: A White Paper presenting the science theme motivating the Athena+ mission, " e-print arXiv:1306. 2307 (2013).
Willingale, R., Pareschi, G., Christensen, F., and den Herder, J.-W., "The Hot and Energetic Universe: The Optical Design of the Athena+ Mirror", e-print arXiv:1307. 1709W (2013).
Bavdaz, M., et al., "The ATHENA telescope and optics status", Proc. SPIE, 10399, 103990B (2017).
Barret, D., et al., "The Athena X-ray Integral Field Unit (X-IFU), " Proc. SPIE, 9905, 99052F (2016). doi: 10. 1117/12. 223243
Pajot, F., et al., "The Athena X-ray Integral Field Unit (X-IFU)", JLTP, published online first (2018). doi: 10. 1007/s10909-018-1904-5
Rau, A., Meidinger, N., Nandra, K., Porro, M., Barret, D., Santangelo, A., Schmid, C., Struder, L., Tenzer, C., Wilms, J., Amoros, C., Andritschke, R., Aschauer, F., Bahr, A., Gunther, B., Furmetz, M., Ott, B., Perinati, E., Rambaud, D., Reiffers, J., Treis, J., von Kienlin, A., Weidenspointner, G., "The Hot and Energetic Universe: The Wide Field Imager (WFI) for Athena+", e-print arXiv:1308. 6785 (2013).
Meidinger, N., Barbera, M., Emberger, V., Fürmetz, M., Manhart, M., Müller-Seidlitz, J., Nandra, K., Plattner, M., Rau, A., Treberspurg, W., "The Wide Field Imager instrument for Athena, " Proc. SPIE, 10397, 103970V (2017). doi: 10. 1117/12. 2271844
Treberspurg W., Andritschke R., Bähr A., Behrens A., Hauser G., Lechner P., Meidinger N., Müller-Seidlitz J., Treis J., "Studies of prototype DEPFET sensors for the Wide Field Imager of Athena, " Proc. SPIE, 10397, 103970U (2017). doi: 10. 1117/12. 2274032
Perinati E., Barbera, M., Diebold S., Guzman A., Santangelo A., Tenzer C., "Preliminary assessment of the ATHENA/WFI non-X-ray background", Exp Astron., 44, 387 (2017). doi: 10. 1007/s10686-017-9541-6
Barbera M., Branduardi-Raymont G., Collura A., Comastri A., Eder J., Kamisi?ski T., Lo Cicero U., Meidinger N., Mineo T., Molendi S., Parodi G., Pilch A., Piro L., Rataj M., Rauw G., Sciortino L., Waver P., "The optical blocking filter for the ATHENA Wide Field Imager: ongoing activities towards the conceptual design", Proc. SPIE, 9601, 960109 (2015). doi: 10. 1117/12. 2189326
Meidinger N., et al., "Development of the wide field imager instrument for ATHENA", Proc. SPIE, 10699 in press. (2018).
Born M. and Wolf E., "Principles of Optics", 6th ed., Cambridge Univ. Press (UK), ISBN 0521639212 (1997).
Aleksandar D. Rakic., "Algorithm for the determination of intrinsic optical constants of metal films: application to aluminum", Appl. Opt. 34, 4755-4767 (1995). doi: 10. 1364/AO. 34. 004755
Henke B. L. et al. " X-ray interactions: photoabsorption, scattering, transmission, and reflection at E=50-30000 eV, Z=1-92", Atomic Data and Nuclear Data Tables, 54, 181-342, (1993).
Handbook of Optical Constants of Solids, (1985), Edited by Edward D. Palik, ISBN: 978-0-12-544415-6
Sciortino, S., et al., "The Hot and Energetic Universe: Star formation and evolution", eprint arXiv:1306. 2333 (2013).
Rataj M., Polak S., Palgan T., Kamisi?ski T., Pilch A., Eder J., Meidinger N., Plattner M., Barbera M., Parodi G., D'Anca F., "The filter and calibration wheel for the ATHENA wide field imager", Proc. SPIE, 9905, 990568 (2016). doi: 10. 1117/12. 2235411
Barbera M, Austin K, Collura A, Flanagan A, Jelinsky R, Murray S, Serio S, Zombeck M, "Development of the UV/ion shields for the Advanced X-ray Astrophysics Facility high-resolution camera (AXAF HRC)", Proc. SPIE, 2280, 214-228 (1994). doi: 10. 1117/12. 186815
Meehan R, Murray S, Zombeck V, Kraft P, Kobayashi K, Chappell H, Kenter T, Barbera M, Collura A, Serio S, "Calibration of the UV/ion shields for the AXAF High-Resolution Camera", Proc. SPIE, 3114, 74-100 (1997). doi: 10. 1117/12. 283790
Villa G. E., Barbera M., Collura A., La Palombara N., Musso C., Serio S., Stillwell R., Tognon P., Turner D. C., "The optical/UV filters for the EPIC experiment", IEEE Transactions on Nuclear Science, 45, 921-926 (1998). doi: 10. 1109/NSSMIC. 1997. 672658
Barbera M, Agnello S, Buscarino G, Collura A, Gastaldello F, La Palombara N, Lo Cicero U, Tiengo A, Sciortino, L, Varisco S, Venezia A M, "Status of the EPIC thin and medium filters on-board XMM-Newton after more than 10 years of operation: 1) laboratory measurements on back-up filters", Proc. SPIE, 8859, 885914 (2013). doi: 10. 1117/12. 2030896
Gastaldello F, Barbera M, Collura A, La Palombara N, Lo Cicero U, Sartore N, Tiengo A, Varisco S, "Status of the EPIC thin and medium filters on-board XMM-Newton after more than 10 years of operation: 2) analysis of in-flight data", Proc. SPIE, 8859, 885915 (2013). doi: 10. 1117/12. 2030897
Tawara Y., et al., "Development of ultra-thin thermal shield for ASTRO-H x-ray telescopes", Proc. SPIE 8147, 814704 (2011). doi: 10. 1117/12. 893368
Iizuka R., Hayashi T., Maeda Y., Ishida M., Tomikawa K., Sato T., Kikuchi N., Okajima T., Soong Y., Serlemitsos P. J., Mori H., Izumiya T., Minami S., "Ground-based x-ray calibration of the Astro-H/Hitomi soft x-ray telescopes", J. Astron. Telesc. Instrum. Syst. 4(1) 011213 (2018). doi: 10. 1117/1. JATIS. 4. 1. 011213
Barbera M., Winter B., Coker J., Feroci M., Kennedy T., Walton D., and Zane S., "Baseline design of the filters for the LAD detector on boad LOFT", Proc. SPIE, vol. 9144, 914466 (2014). doi: 10. 1117/12. 2057408
Cavadi A, Artale A, Barbera M, Collura A, Powell R, Varisco S, "Measurement of optical constants n and k of lexan and polyimide", PROC. SPIE, 3765, 805-815 (1999). doi: 10. 1117/12. 366568
Sciortino, L., Lo Cicero, U., Magnano, E., Píš, I. and Barbera, M. "Surface investigation and aluminum oxide estimation on test filters for the ATHENA X-IFU and WFI detectors, " Proc. SPIE, 9905, 990566 (2016). doi: 10. 1117/12. 2232376.
Meidinger N., Eder J., Fürmetz M., Nandra K., Pietschner D., Plattner M., Rau A., Reiffers J., Strecker R., Barbera M., Brand T., Wilms J., "Development of the wide field imager for Athena", Proc. SPIE 9601, 96010H (2015). doi: 10. 1117/12. 2187012
ESA, "Technology Readiness Levels Handbook for Space Applications", TEC-SHS/5551/MG/ap (2008).
Parodi G., et al., "Structural modeling and mechanical tests supporting the design of the ATHENA X-IFU thermal filters and WFI optical blocking filter", Proc. SPIE 10699, in press. (2018).
Barbera M., and D'Anca F., "ATHENA-Wide Field Imager Optical Blocking Filters Mechanical Design and Interface Requirements", ATHENA-UNIPA-TR002-2018, issue 1. 0 (May 2018).
