RITE SPACE ACTIVITIES (TODAY and FUTURE)

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X-ray Optics Wolter versus KB system
Veronika Marsikovaa, Libor Sveda b, Adolf
Inneman a, Jiri Marsik a, Rene Hudecc, Ladislav
Pinab a) Rigaku Innovative Technologies Europe,
s.r.o. b) Czech Technical University in Prague,
FNSPE c) Astronomical Institute of Academy of
Sciences of Czech Republic
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Motivation

• Manufacturing Wolter system needs very expensive
  mandrels (3D aspheric).
• Manufacturing KB system can be easier and cheaper
  (2D aspheric).
• Substrates can be glass and/or silicon with
  excellent flatness and micro-roughness which is
  necessary for long focus optics.

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Wolter system

• Double reflection X-ray Optics - Wolter type I
  optics consists of rotationally symmetric mirrors
  which are parabolic mirror followed by a
  hyperbolic mirror.
• Set of nested mirrors is arranged concentrically
  to the optical axis. Each ray coming is
  reflected at the parabolic surface first, then at
  the hyperbolic surface.
• The quality of the focal spot image of the X-ray
  source depends on quality of substrates (shape,
  microroughness).
• Optical error is rectified (astigmatic and coma
  error).
• Replicated technology requires very expensive
  mandrel.

XMM
http//imagine.gsfc.nasa.gov
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KirckPatrick Baez system

• Double reflection X-ray Optics consists of two
  mirror sets one is aligned vertically and the
  second is aligned horizontally.
• Both mirrors have to be curved parabolically
  the first mirror focuses in vertical plane and
  the second mirror focuses in horizontal plane.
  Single focal point is formed in the crossection
  of the two focal planes.
• The quality of the focal spot image depend on
  quality of substrates (shape, microroughness).
• Technology is not necessarily based on precise
  and expensive mandrel.
• Classic technologies for laboratory KB-mirrors
  are expensive, complicated and based on heavy
  optics.

http//www.x-ray-optics.de
http//imagine.gsfc.nasa.gov/
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Design and simulation
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Comparison
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Focal length
W system
L
KB system
2L
If W and KB have the same aperture, focal length
of KB system is twice as large as Wolter system.
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Input conditions

• Minimum distance between mirrors 1 mm
• Energy range 1.0 10.0 keV
• Last mirror reflection
• 70 reflection (after 1st reflection _at_ 1keV)?
• 50 reflection (after 2nd reflection _at_ 1keV)?

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Aperture optics system
KB system
W system
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Reflectivity at first mirror set(Focal length
10m KB and 20m W)?
W system
KB system
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Source spectrum

• Crab Nebula

Toor Seward (1974)
Images of Crab Nebula from Chandra X-ray
Observatory. Physics News Graphics, AIP.
http//chandra.harvard.edu/photo/0052/index.html
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Off-axis source images(Focal length 10m KB and
20m W)?
KB system
W system
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Off-axis source images(Focal length 20m KB and
40m W)?
KB system
W system
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Focal peak intensity not normalized
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Focal peak intensity - normalized
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Focal FWHM mm not normalized
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Focal FWHM arcsec normalized
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Focal length optimization

• ideal focal length for both sets results in
  asymmetric peak
• focal length of mirror set one was optimized
• Difference ideal-optimal 4 mm

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Next year enhancements

• Reflectivity efficiency maps.
• Segment based KB design as a result of efficiency
  maps (flower-like KB)?.
• Comparison to standard designs.

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Flower like KB
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Manufacturing
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RITE technologies

• Based on industrial substrates (glass and or Si
  wafer) with very good surface quality (shape,
  microroughness) gt low cost.
• Technology process retains surface quality and
  polishing process is not needed.
• Technology allows composite materials and/or
  relatively light-weight materials.
• Cubic geometry means easer assembling of the
  system.

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Gorenstein, Paul,Proc. SPIE Vol. 3444, p. 382-392
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MFO technology

• X-ray optics
• Substrates
• Glass
• Silicon
• Nickel
• Type of optics
• KB system
• Lobster Eye

ISRO Meeting Prague, October 2009
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Si substrates
AFTER
BEFORE
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Si substrates
Comparison of convex side of bent Si wafers
(left) and flat Si wafer (right)
Analysis of formed Si wafer by TH profilometer.
Analysis of formed Si wafer by AFM.
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RITE modules

• Model based on ray-tracing (11 profiles)?
• Two sets of mirrors from Si chips 100x100x0.525
  mm
• Total optics length 600 mm, aperture 40x40 mm

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Tests
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Conclusion

• KB vs. W
• Comparable effective area at f2f
• KB has more homogeneous intensity
• KB has comparable angular resolution
• KB samples manufactured from multiple small Si
  chips (substrates)
• Tests are expected at the beginning of 2010
• Future enhancements of KB (simulation
  manufacturing silicon and glass substrates)

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Acknowledgment

• We acknowledge support of
• Grant Ministry of Education, Youth and Sports,
  grant Applications of Kirkpatrick Baez Imaging
  Systems in Space, No. ME09004.
• Grant ESA - PECS, grant Novel X-ray Optics
  Technologies for ESA X-ray Astrophysics
  Missions, No. 98039.
• Grant Agency of Academy of Sciences of the Czech
  Republic, grant Material and X-Ray Optical
  Properties of Formed Silicon Monocrystals, No.
  IAAX01220701.
• Project MSMT INGO Vyzkum v ramci Mezinarodniho
  centra husteho magnetizovaneho plasmatu.

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YOUR ATTENTION.?????????????????? ??? ???
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