1 / 19

Solar orbiter – EUS instrument mechanical design

Solar orbiter – EUS instrument mechanical design. Tim Froud and Doug Griffin. Talk outline. Mechanical-thermal-optical considerations for the Primary Mirror Silicon Carbide Testbed Study Structural layout. Primary mirror WFE under Solar IR Loads.

beulah
Download Presentation

Solar orbiter – EUS instrument mechanical design

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. Solar orbiter – EUS instrument mechanical design Tim Froud and Doug Griffin

  2. Talk outline • Mechanical-thermal-optical considerations for the Primary Mirror • Silicon Carbide Testbed Study • Structural layout

  3. Primary mirror WFE under Solar IR Loads • The Solar radiation load will introduce thermal gradients in the Primary Mirror • Thermal stresses • Internal mirror temperature gradients • Possibly also from CTE mismatches • The thermal load will vary by roughly an order of magnitude during each orbit • Goal is to meet the optical performance during the encounter and during down link phases of the orbit • Mirror distortions will introduce distortions in the surface of the mirror which will reduce the spectral and spatial resolution of the instrument

  4. Primary Mirror WFE Tolerance Estimates • Calculation based on encircled energy and are to be considered provisional • Given the Spectral and Spatial resolution requirements: • Derived requirement on PSF ~ 10um: • Mirror rms WFE: ~l/30 i.e. 21nm rms

  5. NI Primary Mirror Distortion EstimatesModel Geometry 5mm 5mm Uniform heat load B/C 35kW/m2 Fixed Temperature B/C 25mm 40mm 5mm 10mm Axis of symmetry

  6. NI Primary Mirror Distortion EstimatesMaterial Assumptions • Assume that the mirror is made from homogeneous Silicon Carbide • E=249GPa • Poission ratio: 0.16 • CTE: 2.7x10-6 m/m • Thermal conductivity: 127 W/m/K • Mirror is absorbing in the IR • Thermal interfaces have identical mechanical properties as Mirror • No interface stresses

  7. NI Primary Mirror Distortion EstimatesTemperature Distribution

  8. NI Primary Mirror Distortion EstimatesThermal distortions

  9. NI Primary Mirror Distortion EstimatesConclusions • The analysis has to be considered as a preliminary estimate • Optical • Thermal • Mechanical • Layout • Nonetheless: The conclusion is that the thermal control of the Primary Mirror will have to be considered in tandem with the overall instrument optical performance • It could be one of the largest challenges for the instrument design • Rastering of the instrument via the Primary mirror could be very difficult with the complexity of the thermal control

  10. Primary Structure Material SelectionTest Bed Study • A study was carried out on a SiC based Optical Bench • Looked at the practical details of designing structural components in SiC • Very useful in terms of understanding: • Detailed manufacturing processes • Achievable tolerances • Mounting and interface designs • Lightweighting • Non-destructive Testing • Procurement of test-bed did not proceed due to cost • Promising outcome for Flight-build

  11. Primary Structure Material SelectionTest Bed Study

  12. Components of system

  13. Components of system

  14. Optical bench

  15. Primary mirror

  16. Slit mechanism

  17. Grating

  18. Detectors and electronics

  19. Enclosure and baffling

More Related