ATHENA OpticsFirst German ATHENA Science Workshop, January 13, 2012, Garching, Germany

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ATHENA Optics

Based on Silicon Pore Optics (SPO)

“owl-eye design”

ATHENA OpticsFirst German ATHENA Science Workshop, January 13, 2012, Garching, Germany

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Athena Telescope Design

• Geometric area: > 1 m2

• Configuration: 2 telescope units with modular (approximated) Wolter I optics

• Radii: 0.15…0.30 – 0.9 m

• Focal length: 10.5…12 m

• Coating: Ir + B4C overcoating

Other telescope configurations have been discussed…

ATHENA OpticsFirst German ATHENA Science Workshop, January 13, 2012, Garching, Germany

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Athena Telescope Design

Reflectivity with Ir coating

ATHENA OpticsFirst German ATHENA Science Workshop, January 13, 2012, Garching, Germany

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Effective Area depending on Focal Length F

Rin = 0.15 mIr coating + 8 nm B4C overcoating

ATHENA OpticsFirst German ATHENA Science Workshop, January 13, 2012, Garching, Germany

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Off‐Axis Performance

Vignetting function (left) and PSF HEW as a function of off-axis angle (right)from R. Willingale

ATHENA OpticsFirst German ATHENA Science Workshop, January 13, 2012, Garching, Germany

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Athena Optics Technology

Silicon Pore Optics (SPO): based on super-polished silicon wafers; use of manufacturing techniques from semi-conductor industry.

Need for new mirror technology:• Limited payload mass and large mirror area require light weight

optics.• Science goals require moderate to high angular resolution (<10’’).• Both together cannot be achieved with state-of-the-art nickel

electroforming technology.

Solutions:• Silicon Pore Optics (ESA led studies for XEUS/IXO/Athena)• Slumped Glass (studies at NASA, MPE, OAB)

≈7 cm

ESTEC status presentation 28 September 2011 7

Stacking of silicon pore optics – plate production

300 mm

66 mm

0.8 mm

Commercial 300 mm diameter double-sided polished waferPlate dicing and ribbing

ESTEC status presentation 28 September 2011 8

Stacking of silicon pore optics – plate production

Plate wedging, coating and bending

ESTEC status presentation 28 September 2011 9

Stacking of silicon pore optics – stack production

Plate stacking

ESTEC status presentation 28 September 2011 10

Stacking of silicon pore optics – module production

Module integration

ESTEC status presentation 28 September 2011 11

Stacking of silicon pore optics – petal integration

1.1 m

Module integration into petals

ESTEC status presentation 28 September 2011 12

Robotic Stacking in cleanroom 

ESA-led ATHENA/IXO Optics Development Status, SPIE 2011

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Full sized stacks

R < 0.3 m

Have produced nominal45 plate stacks at 2 m radius

ESA-led ATHENA/IXO Optics Development Status, SPIE 2011

SPO Mirror Plate parameters:

IXO (f=20m) TDA (2011) ATHENA (f=11.5 m)

Radius [m] 0.25 - 1.75 0.74 0.25 - 0.9 (0.15)Plate Length [mm] 28 - 194 67 30 - 111 (186)Wedge height [μm] 0.27 - 5.6 0.63 & 1.9 0.52 - 5.6 (3.1 & 9.4)

Move from IXO to Athena: Mirror PlatesChange to smaller radii and shorter focal length

ESTEC status presentation 28 September 2011 15

First stacks produced

• Have produced several 0.74 m radius stacks– Successfully stacked 20 plates, both types of new wedged plates– Bonding at smaller radius and with larger wedged plates no problem– New surface metrology shows improved cleanliness and close to 100% 

bonded area

ESTEC status presentation 28 September 2011 16

Developed lithographic plate coating

• 12 nm Ir and 7 nm B4C coated plates• Successfully stacked and bonded with 0.74 m robot

ESA-led ATHENA/IXO Optics Development Status, SPIE 2011

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Inner radii  

R < 0.3 m

first successful trial at 0.3 m radius 

ESTEC status presentation 28 September 2011 18

Bend test inner radii• Mirror plate could be bent to a radius of curvature of ≈55 mm (@≈10N)• Bending is a factor of ≈2.7 higher than for Athena innermost mirror modules with 

radius of curvature of 150 mm

ESTEC status presentation 28 September 2011 19

‐10

0

10

20

30

40

50

60

2005 2006 2007 2008 2009 2010 2011 2012 2013

HEW

 [arcsec] at 3

 keV

stacking robot (linear)XOU1+2 ? XOU3: plate quality

stacking robot (modular)improved cleanliness

stacking robotimpr. plates, 

cleaner

stacking robottrue Wolter 

XOU‐1 (4p)

XOU‐2 (4p)

XOU‐3 (4p)

XOU‐5 (4p)

XOU‐7 (4p)MM allocation (4.3")

MM(4p) allocation (3.7")

 Generation I (HPO)

 Generation II (SPO, SPORT)

 Generation III (SPIN)

 Generation IV 

Measured X-ray HEW performance of SPO f=50 m Mirror Modules (complete area of four mounted plates, in double reflection, at 3 keV)

ATHENA MM allocation (9.0”)

X‐Ray Performance Tests

ATHENA OpticsFirst German ATHENA Science Workshop, January 13, 2012, Garching, Germany

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Thank you for attention

Thanks to M. Bavdaz (ESA) and M. Collon (cosine) for providing slides and movie on SPO