1 / 47

Expected Improvements in Imaging

Expected Improvements in Imaging. G. Pareschi. INAF – Osservatorio Astronomico di Brera. Outline. Historical remarks on high energy imaging optics Hard X-ray focusing telescope: Simbol-X Wide-field X-ray optics Future large size X-ray missions (XEUS).

judah-william
Download Presentation

Expected Improvements in Imaging

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Expected Improvements in Imaging G. Pareschi INAF – Osservatorio Astronomico di Brera

  2. Outline • Historical remarks on high energy imaging optics • Hard X-ray focusing telescope: Simbol-X • Wide-field X-ray optics • Future large size X-ray missions (XEUS)

  3. X-ray astronomical optics history in pills • 1895: Roentgen discovers “X-rays” • 1948:First succesfull attempt of the focalization of an X-ray beam by a total-reflection optics (Baez) • 1952: H. Wolter proposes the use of two-reflection optics based on conics for X-raymicroscopy • 1960: R. Giacconi and B. Rossi propose the use of grazing incidence focusing optics for X-ray telescopes • 1962: discovery by Giacconi et al. of Sco-X1, the first extra-solar X-ray source • 1963: Giacconi and Rossi fly the first (small) Wolter I optics to take images of Sun in X-rays • 1965: second flight of a Wolter I focusing optics (Giacconi + Lindslay) • 1973:SKYLAB carry onboard two small X-ray optics for the study of the Sun • 1978:Einstein, the first satellite with focusing optics enterely dedicated to X-rays • 1983: EXOSAT operated (first European mission with X-ray optics aboard) • 1990:ROSAT, first All Sky Survey in X-rays by means of a focusing telescope with high imaging capabilities • 1993:ASCA, a multimudular focusing telescope with enhanced effective area for spectroscopic purposes • 1996:BeppoSAX, a broad-band satellite with Ni electroformed replicated optics • 1999: launch of Chandra, the X-ray telescope with best angular resolution, and XMM-Newton, the X-ray telescope with most Effective Area • 2004: launch of the Swift satellite devoted to the GRBs investigation (with aboard XRT) • 2005: launch of Suzaku with high throughput optics for enhanced spectroscopy studies with bolometers

  4. Imaging experiments using Bragg reflection from “replicated” mica pseudo-cylindrical optics E. Fermi – Thesis of Laurea, “Formazione di immagini con i raggi Roentgen” (“Imaging formation with Roentgen rays”), Univ. of Pisa (1922) Thanks to Giorgio Palumbo!

  5. Present Astronomical optics technologies: HEW Vs Mass/geometrical area

  6. Present Astronomical optics technologies: HEW Vs Mass/geometrical area

  7. Present Astronomical optics technologies: HEW Vs Mass/geometrical area New Configuration

  8. Cas A ESA credits X-ray optics by Ni electroforming replication BeppoSAX Jet-X/Swift XMM-Newton

  9. Cas A ESA credits X-ray optics by Ni electroforming replication Now the Ni electroforming approach, born and set-up by Citterio et al. For BeppoSAX is a technology almost of-the-shelf for small/medium size missions. It will be used for e-Rosita, SVOM and Polar-X BeppoSAX Jet-X/Swift XMM-Newton

  10. Wolter I geometry The focusing problem in the hard X-ray region (> 10 keV) F = focal length R = reflectivity L = mirror height q = incidence angle

  11. Wolter I geometry Aeff F2 x qc2 x R2 but The focusing problem in the hard X-ray region (> 10 keV) F = focal length R = reflectivity L = mirror height q = incidence angle

  12. Wolter I geometry Aeff F2 x qc2 x R2 but The focusing problem in the hard X-ray region (> 10 keV) At photon energies > 10 keV the cut-off angles for total reflection are very small also for heavy metals  the geometrical areas with usual focal lengths (> 10 m) are in general negligible F = focal length R = reflectivity L = mirror height q = incidence angle

  13. Multilayers Focal Length Vs. Diameters for SIMBOL-X and other X-ray telescopes 0.6 o Aeff  F2 x qc2 x R2

  14. Multilayers Focal Length Vs. Diameters for SIMBOL-X and other X-ray telescopes 0.6 o The Formation Flight architecture offers the opportunity to implement long FL telescopes! Aeff  F2 x qc2 x R2

  15. q Focal length The formation flight contribution

  16. q Focal length The formation flight contribution

  17. q Focal length The formation flight contribution

  18. q Focal length The formation flight contribution

  19. Wide band multilayers X-ray supermirrors Optical supermirrors in a beetle skin b) • Beetle Aspidomorpha Tecta; • TEM section of the skin • b) Reflectivity in the optical band nel visibile. CREDITS: Dr. Naoyuki Ohnishi Chubu University – Japan Dr. Yasushi Ogasaka Nagoya Univ. - Japan a) 1 mm CREDITS: Dr. A. R. Parker – Dep. Of Zoology Oxford University – UK

  20. Top-level scientific requirements

  21. Simbol-X core scientific objectives • Black hole physics and census • resolve at least 50% of the CXB in the energy range where it peaks (20 -30 keV) • solve the puzzle on the origin of the hard X–ray emission from the Galactic centre • constrain the physics of the accretion flow onto both SMBH and solar mass BH • Particle acceleration mechanisms - constrain acceleration processes in relativistic Jets of blazars and GRB; - probe acceleration mechanisms in the strong EM and gravitational fields of pulsars; - measure the maximum energy of electron acceleration in supernova remnants shocks; These two broad topics define the core scientific objectives ofSimbol-X

  22. Simbol-X core scientific objectives • Black hole physics and census • resolve at least 50% of the CXB in the energy range where it peaks (20 -30 keV) • solve the puzzle on the origin of the hard X–ray emission from the Galactic centre • constrain the physics of the accretion flow onto both SMBH and solar mass BH • Particle acceleration mechanisms - constrain acceleration processes in relativistic Jets of blazars and GRB; - probe acceleration mechanisms in the strong EM and gravitational fields of pulsars; - measure the maximum energy of electron acceleration in supernova remnants shocks; These two broad topics define the core scientific objectives ofSimbol-X

  23. Image quality & large FOV 15” HPD + 12” FWHM High throughput 0.3 – 1  103 cm2 @30keV Low internal background & Rejection of CXB from outside the FOV Wide energy response (0.5 – 80 keV) with high spectroscopic performances Implementation Challenges

  24. C Pt Multilayer coated Ni mirror shells tested at Panter See S. Romaine et al., SPIE Proc., 5900 (2005) • N.B.: a collaboration SAO/NASA-MSFC/INAF-OAB

  25. Low energy detector (450 mm Silicon) High energy detector (2 mm Cd(Zn)Te) Active shielding The Simbol-X focal plane assembly • Spectro-imaging system 0.5-100 keV, fast reading • Full size : 8x8 cm2, 128x128 pixels of 625 mm • Operation at ~ -40°C

  26. Simbol-X Optics • Heritage from XMM–Newton : nickel shells obtained by electroforming replication method; low mass obtained via a reduced thickness of shells • Coating : multi-layer Pt/C needed for requirement on large FOV and on sensitivity up to > 80 keV Focal length : 20 m Shell diameters : 30 to 70 cm Shell thickness : 0.2 to 0.6 mm Number of shells :100 N.B. I: The optics module will have both sides covered with thermal blankets N.B. II: a proton diverter will be implemented

  27. Expected Flux Sensitivity

  28. Angular resolution for past & future Hard X-ray Experiments

  29. Wide Field Polynomial optics R. Giacconi, “AN EDUCATION IN ASTRONOMY”, Annu. Rev. Astro. Astrophys. 2005.43: 1- 30, 22 “A further extension of this line of thinking is that experiments could be designed by modelling both the hardware and software as part of the initial design. I myself, together with Richard Burg and Chris Burrows, used this approach in designing in the 1980s what I believe was one of the best experiments I ever conceived. The purpose was to scan the sky and to detect distant clusters of galaxies through their X-ray emission. The idea was that it would be possible to equal or exceed the sensitivity of Chandra with an X-ray telescope of one tenth the area (and cost). This could be achieved by dedicating an entire mission of a small satellite to this purpose and by designing a telescope that would have a >16-fold increase of the field of view with respect to Chandra. ……..”

  30. X-ray optics with polynomial profile • Mirrors are usually built in the Wolter I (paraboloid-hyperboloid) configuration which provides, in principle, perfect on-axis images. • This design exhibits no spherical aberration on-axis but suffers from field curvature, coma and astigmatism, which make the angular resolution to degrade rapidly with increasing off-axis angles. • More general mirror designs than Wolter's exist in which the primary and secondary mirror surfaces are expanded as a power series, and the height-to-focal-length ratio optimized • These polynomial solutions are well suited for optimization purposes, which may be used to increase the angular resolution at large off-axis positions, degrading the on-axis performances (Burrows, Burgh and Giacconi 1992) • A trade-off of the whole optics assembly of a wide-field telescope can further on increase the imaging capabilities off-axis of wide-field polynomial optics

  31. WFXT (ASI Phase A study) Tests @ Panter-MPE & Marshall XRF WFXT (epoxy replication on carrier in SiC) Ø = 60 cm Focal Length = 300 cm HEW = 10 arcsec Ref:. O. Citterio, et al., ”, SPIE Proc., 3766, 198 (1999).

  32. EDGE-WFI concept (I)

  33. EDGE-WFI concept (II)

  34. EDGE-WFI concept (II) Flux Sensitivity (0.5 – 2 keV): 1.5 10-16 cgs in 1 Msec

  35. Geometric Area and Angular resolution for past and future X-ray telescopes

  36. XEUS (3 x10-18) @ 0.2–8 keV; 4σ Sensitivity (cgs) Effective Area Angular Resolution • 1 (1.5) m2 @ 0.2 keV • 5 m2 @ 1 keV • 2 m2 @ 7 keV • 1 m2 @ 10 keV • (0.1) m2 @ 30 keV 5 (2) arcsec @ < 10 keV 10 arcsec @ 40 keV Field-of-View 7 (10) arcmin diameter: WFI, HXI 1.7 arcmin diameter: NFI

  37. XEUS Effective Area

  38. Effective Area (cm2) Area-to-Mass ratio (cm2/kg) HEW (arcsec) 400 0.8 0.5 1400 6.0 15 (12) 50000 35 2 Chandra XMM XEUS XEUS Optics Parameters • Aperture radii 0.67–2.1 m • Grazing reflection angles 0.27–0.86 deg • Focal length 35 m • Plate scale 170μm/arcsec • Total mirror weight ≈ 1.3 tons Optics error Budget Specifications (arcsec) Inherent Intrinsic Extrinsic Environment Total Goal 1.4 1.2 0.5 0.5 2.0 Req. 1.8 3.7 2.0 2.0 5.0

  39. X-ray Pore Optics System Double-Cone approximation N.B.:concept introduced by D. Willingale et al, Capri 1994

  40. Pore Optics technology Credits: ESA & Cosine

  41. Cellular solids: light weight structures with a very high stiffness Foamed Regular cellular structures

  42. Preliminary imaging tests onto two-reflection optics (I) Credits: ESA, Cosine, MPE Collon et al, SPIE Proc 67898, in press (2007)

  43. Preliminary imaging tests onto two-reflection optics (II) Extrapolated HEW for the 4 the first four plates and the entire stack width (~1.2 cm2) of 17 arcsec HEW (BUT JUST IN ONE DIRECTION!) Creditd: Cosine & ESA Extrapolated performance of XOU-3 taking into account beam spreading: At 25 m distance (A) the azimuthal focussing becomes visible and results in a focus at 50 m distance (B). The HEW calculated for the image B (plates 1-4, all 60 pores) is 17” without any corrections Collon et al, SPIE Proc 67898, in press (2007)

  44. Alternative approach: hot sluping of thin glass segments 0.4 mm thick segment (without integration) HEW = 5 arcsec

  45. 1: Borofloat sheet and mold Borofloat glass mold 3: Metrology (astatic support) 4: Ion Beam Figuring (if necessary) 2: Slumping Oven Segment production sequence @ INAF-OAB Ghigo et al, 2006

  46. M4 slumping (l/11 on 80 mm) (l/2.9 on 130 mm) Fringes between mould and glass Slumping tests on Borofloat33™ glass sheets The use of a vacuum muffle with the capability to apply on the glass a uniform controlled pressure (~150 g/cm2) provided the best results so far. The muffle protect the glass from the dust of the oven and the vacuum avoid the convection of air slumping (l/11 on 80 mm 50 nm rms) (l/2.9 on 130 mm) No dust specks Circular fringes very sharp up to the edge of the glass 150 mm Zerodur K20 mould

  47. SIMBOL-X

More Related