spo development - isdc, data centre for astrophysics · 2018. 10. 24. · •coat single layers...

SPO development

Max Collon on behalf of the SPO team

25 Sep 2018 SPO development - Athena conference Palermo 1

SPO development team


today

Mirror plates and mirror modules:• Industrial production• Performance optimisation• Ruggedisation

Reflector coatings:• Recipe development• Industrialisation

Mirror Assembly:• MM AIT• Telescope demonstrator

MARESA activities carried out by SPO team


Main focus of 2018 is improving f=12 m resolution


Overall status – angular resolution is improving


XOU-0041B

BESSY XPBF 2 dataDouble reflection

10x2 mirrors (Ageom 6.6 cm2)r = 737 mmE = 1.64 keVf = 12 m SPO

XOU-0051 XOU-0054 XOU-0060B

Three areas of improvement

• Side effects

• Meridional curvature

• Stochastic errors and print-through

HEW improvement – meridional curvature

HEW very sensitive to meridional curvature of stacks

• Focuses light of each pore

• Curvature required for shorter focal length optics, SPO originally designed for f=50 m

• The sum of the P and S curvatures matters

Too much curvature degrades HEW very quickly

Improved metrology identified excess meridional curvature in most stacks produced

30 Aug 2018 SPO performance review 2 6

Ray trace based on r=737 mm optical design

Meridional curvature – improving metrology

FRT system was so far insufficient to properly measure meridional curvature

• Main purpose was to measure mid-and high-spatial frequency errors

Developed in the last months method to separate short from long-scale figure errors

• Can now be used to optimize both error terms separately

• Improved FRT calibration procedure to return absolute curvature

Have now metrology in house to investigate why some stacks have correct curvature and others not


Side effects – origin understood

Side effects confirmed to originate from outer ribs touching and bonding prior to central parts of plate (causing initially unbonded ribs in between)

• Due to plate edges insufficiently following the die shape

Tested methods to improve the side effects after initial bond

• Increases the bonded area, but not 100% solution

Next step is to evolve the die structure to improve controlled plate deposition


Print through effects – reduced through die adjustment

Successfully CNC milled for the first time an electrostatic die

• Reduced imprint of areas in between electrodes

Solution will now be deployed to other radii dies


Performance progressing by executing agreed plan

Worked on all of the process improvements discussed with ESA and external reviewers

• Made many stacks in different configurations and tested at BESSY and PANTER as XOUs• Data analysis and synthesis is still ongoing, showed today current status

Identified additional and currently dominant error term

• Too strong meridional curvature results in PSF degradation• Not present on all stacks, ongoing work to identify root cause• Reducing the error term results in improved HEW, modelled and demonstrated in X-ray

Matured understanding of different contributors to stack performance

• Side effects• Entry/exit effects• ESC die structure• Cleanliness

Working closely with ESA to prepare SPO for MFR (2019) and MAR (2021)


Inner radius stack development - restarting

Had achieved milestone of first inner radius stacks already end of 2016

• Demonstrated r=250 mm 35 plate stacks

• Larger rib pitch of 2.3 mm

Re-commissioned stacking robot in 2017 and 2018 for middle radii activities

• MM production for AIT activities and HEW improvement

New 4th stacking robot now almost completed

• Re-start stack production in Q4/2018


Outer radius development progressing well

Produced first 35 plate stacks

• Handing over experimental stacking process to operators

• Will be used for vibration and shock testing to gather first data points

Optimising the production to minimize slope errors

• stacking recipe

• cleaning recipe

Stacked successfully coated plates

• Required to measure in double reflection in x-rays due to larger angle of incidence and higher energy of XPBF 2 (1.64 keV)

X-ray tests planned when BESSY re-opens in Nov 2018


Plate coating process and ramp-up under development

Need coating only between rib locations

• Bonding area to be kept free• Requires lithographic masking• Residual coating stress only in longitudinal

direction where rib is stiffening

Coating needs to be compatible with stacking

• SC-1 cleaning removes any organic contamination• Plate stacking process (electrostatic chucking)• Thermal annealing up to 150 deg C

Requirement to coat >100.000 plates

• Have two plate suppliers, centralize the coating before the stacking

• Coat single layers (Ir), bi-layers (Ir + low-z material) and multi-layers

Selected industrial mass production type machine together with DTU and ESA

• Using magnetron sputtering to maintain in sync with DTU process• Traded different systems regarding production speed, cost, quality

13 SPO development - Athena conference Palermo 25 Sep 2018

Magnetrons Plasma cleaner

Plasma cleaning substrate essential for coating


Technology development – straylight reduction


Possible to roughen the backside of the plates

• Backup in case further straylightreduction required

Ruggedisation – project to complete mid 2019

Preparing for f=12 m MM shock testing

• Successfully shock tested dummy MM to validate interfaces and data recording systems

Will assembly middle radius MM to perform shock test in Q4/2018

• Compare gathered stack level data to MM data• Close phase 1 of project

Commissioning ‘wet’ annealing system

• Increase bond strength by 20-30% and repeat stack level tests in phase 2

Procured ringing plate matching Ariane 64 specs, with ‘knee’ at 400 Hz instead of 1000 Hz

• To be installed after closure of phase 1

Starting to shock test outer and inner stacks as part of phase 2 work


SPO moving full steam ahead for Athena MAR in 2021

SPO completed transition to f=12 m on all three radii

• Can produce stacks for all three representative radii• Just manufactured first generation of outer radii stacks• Mastered critical step of bonding innermost stack. Inner radius stacking will recommence Q4

2018• Demonstrated possibility of larger rib pitch on inner radius, to be deployed to other radii

Focus in 2018 on process development for middle radius, preparing for MFR and MAR

• Working mainly on the angular resolution on stack level• First results show already improvement in performance (9” on 70%, 5.4” on 15%)• Iterative development process of stacking and systematic step-by-step improvement

In parallel we work on production ramp-up for larger scale production

• Required to be completed in time for EQM and MAR to reach TRL 6• Already reduced stacking times, added 2nd plate supplier, scaled up plate production• Industrial high-volume coating machine starts to deliver first good results as well

17 SPO development - Athena conference Palermo 25 Sep 2018

measurement systemscosineOosteinde 362361 HE WarmondThe Netherlands

Tel. +31 71 528 49 62Fax. +31 71 528 49 [email protected]


spo development - isdc, data centre for astrophysics · 2018. 10. 24. · •coat single layers...

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