Diapositiva 1

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SIMBOL-X OPTICS
Giovanni Pareschi INAF - Osservatorio Astronomico
di Brera
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Poster presentation related to the SX optics
implementation

• Basso et al., The relation between the weight
  and the quality image in a X-ray telescope, with
  a particular regard to Simbol-X
• Vernani, et al., Feasibility study for the
  manufacturing of the multilayer x-ray optics for
  Simbol-X
• Cotroneo et al, Simbol-X mirror module design
  scientific optimization
• Basso et al, The problem of the calibration of
  SIMBOL-X X-ray telescope
• Spiga et al., The scattering caused by
  microrougnhess in the Simbol-X multilayer coated
  optics
• Romaine, et al, Multilayer coated hard X-ray
  mirrors based on Ni electroformed mirror shells

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OUTLINE

• Designing of the Simbol-X optics
• The technology for the optics fabrication
• Remarks on the calibration issue

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Top-level scientific requirements
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SX Flux Sensitivity
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Advantages of focusing optics versus direct-view
detectors
HEW Half Energy Width circle where 50 of
focused photons is contained
Moreover much better imaging capabilities!
B background flux, Tint integration time, DE
integration bandwidth
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Angular resolution for past future Hard X-ray
Experiments
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IMAGING (I)
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IMAGING (II)
?50 HPD eq. 2?Crab
30HPD? Eq.2?Crab
15HPD? Eq.0.2?Crab
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The focusing problem in the hard X-ray region (gt
10 keV)
At photon energies gt 10 keV the cut-off angles
for total reflection are very small also for
heavy metals ? the geometrical areas with usual
focal lengths (gt 10 m) are in general negligible
F focal length R reflectivity L mirror
height q incidence angle
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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
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Design Constraints

• FOCAL LENGTH 19 m (due to formation flight
  parameters)
• DETECTOR SIZE 7 /1 cm (Size of the LED wafer
  lateral ditering)
• NUMBER OF MIRROR SHELLS 100
• MAXIMUM DIAMETER 70 cm (i.e. as XMM)
• MINIMUM DIAMETER 25 cm (to allow the
  multilayer deposition post facto)
• MASS TO AREA RATIO a reliable number in line
  with angular resolution of at least 20 arcsec
  HEW
• MASS not larger than 480 (TBD) including
  structure

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SIMBOL-X Baseline Design
detector size
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Optics design

• Heritage from XMMNewton 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 gt 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
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Mirror shell production by Ni electroforming
replication
BeppoSAX
Jet-X/Swift
XMM-Newton
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Existing Coating Facilities at INAF-OAB Media
Lario Techn.
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Thickness Vs. Diameter trend for Ni-replicated
optics
HPD 15 arcsec Year 1994
HPD 15 arcsec Year 1999
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Wall thickness/diameter trade-off
Mass including structure 480 kg
Thicknesses 2 times less than XMM
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The use of stiffening rings for handling and
integration of thin mirror shells
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Integration procedure
Temporary spider
Temporary spider must give stiffness to the upper
side of the entire set of shells and must be
removed after gluing of all the shells on the
upper spider.
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Multilayer deposition system
Deposition of the multilayer film onto the
internal surface of a replicated mirror shell
(development activity carried out so far in
collaboration with the Harvard-Smithsonian CfA) ?
particularly well suited for Simbol-X, since
based on large diameter optics
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Multilayer coated Ni mirror shells tested at
Panter
CREDITS Panter/MPE
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The long focal length calibration issue
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Test of very long focal length optics (20 - 30 m)
in pencil beam setup with more than 1 shell
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Programmatic points

• By the end of the Phase a is planned to develope
  and calibrate a couple of multi-shell prototypes,
  caled down of a factor 2 wrt Simbol-X (Focal
  Length 10 m, max diameter 35 cm)
• It is planned the development of a
  diamond-turning facility for the madrel
  fabrication
• In Phase B a fully representative demonstrator
  will be developed and calibrated