The ESA RADGLASS activity: A radiation study of non rad-hard glasses

Transcription

1 The ESA RADGLASS activity: A radiation study of non rad-hard glasses Ilias Manolis (1), Jean-Loup Bézy (1), Ramon Vink (2), Roland Meynart (1) (1) ESA/ESTEC, Directorate of Earth Observation Programmes (2) ESA/ESTEC, Directorate of Technical Quality and Management Ref: IPD-HO-ESA-540

2 Background: The Instrument Perspective idea concept detailed design manufacturing launch 0 A B C D E Assessment & Feasibility What is the right glass for me? ILIAS MANOLIS 18/10/2016 Slide 2

3 Background: Glass and Radiation (*) SPIE (**) (*) Samples from the ESA RADGLASS study (**) D. Doyle, EJSM3IW, ESTEC, 2010 Radiation induces color centers and transmission loss in optical glasses Cerium doping inhibits the formation of color centers thus improving resistance to radiation ( radhard ) ILIAS MANOLIS 18/10/2016 Slide 3

4 RADGLASS: Motivation & Objectives Selecting radhard glasses for the optical design would be the natural choice, but: Cerium tints the glass & shifts the UV-edge towards longer wavelengths Their stock availability cannot be guaranteed long term They are only a few of them (!!!) Hence, the RADGLASS objectives are: To systematically test an extended set of conventional, non-radhard glasses. To assess their response to relatively benign radiation environments (e.g. LEO, GEO). To update already existing measurements, using materials from the latest contemporary manufacturing methods. ILIAS MANOLIS 18/10/2016 Slide 4

5 The ESA RADGLASS study: Contents Materials Selection Facilities Sequence of tests Results Further work Conclusions ILIAS MANOLIS 18/10/2016 Slide 5

6 Materials Selection & Procurement Conducted extended survey internally and externally with our industrial partners Considered currently on-going and future Earth Observations missions / instr. Iterated with the wish lists of optical designers For some materials different grades were considered Materials for use in the UV, VIS & SWIR range (and beyond) Result: More than 100 materials (!) Several manufacturers (e.g. Schott, Ohara, Corning etc.) Glass as well as crystalline materials (e.g. CaF2, MgF2, Quartz, etc.) Typical procurement specification of the RADGLASS samples ILIAS MANOLIS 18/10/2016 Slide 6

7 Facilities: The ESTEC Cobalt-60 facility (*) Photon energies : MeV & MeV Calibration dosimetry implemented ISO accredited Typical Test Plan according to ESCC standard Typical dose rates: 2 krad / hour (*) For more ore information, check: ILIAS MANOLIS 18/10/2016 Slide 7

8 Facilities: Optical Measurement Setup Commercial Spectrophotometer (Agilent Cary 5000 (*) ) Quantity under measurement: Total Transmission Spectral Range: 200 nm 2500 nm Bandwidth = 2 nm / Spectral Sampling Interval = 1 nm Estimated uncertainty : < 1% (VIS) / < 1.5% (UV & NIR) (*) For more information, check: ILIAS MANOLIS 18/10/2016 Slide 8

9 Sequence of Tests A handful of samples in each round Seven irradiation steps /round Up to 500 krad (nominal) Transmission measurements after each step Minimization of time between steps Measurements before & after Some refractive measurements as well Few relaxation measurements (*) Cumulative Total ionizing Dose in water ILIAS MANOLIS 18/10/2016 Slide 9

10 ESA RADGLASS measured total transmission plots for Schott N-SSK5 Sample thickness = 5 mm ± 0.2 mm ILIAS MANOLIS 18/10/2016 Slide 10

11 ESA RADGLASS measured total transmission plots for Schott N-KZFS4HT Sample thickness = 5 mm ± 0.2 mm ILIAS MANOLIS 18/10/2016 Slide 11

12 ESA RADGLASS measured total transmission plots for Schott LF5 Sample thickness = 5 mm ± 0.2 mm ILIAS MANOLIS 18/10/2016 Slide 12

13 ESA RADGLASS measured total transmission plots for Schott N-PK51 Sample thickness = 5 mm ± 0.2 mm ILIAS MANOLIS 18/10/2016 Slide 13

14 ESA RADGLASS measured total transmission plots for Schott SF57HT Ultra Sample thickness = 5 mm ± 0.2 mm ILIAS MANOLIS 18/10/2016 Slide 14

15 ESA RADGLASS measured total transmission plots for Schott N-SF6HT Sample thickness = 5 mm ± 0.2 mm ILIAS MANOLIS 18/10/2016 Slide 15

16 ESA RADGLASS measured total transmission plots for Schott N-BAK4HT Sample thickness = 5 mm ± 0.2 mm ILIAS MANOLIS 18/10/2016 Slide 16

17 ESA RADGLASS measured total transmission plots for Schott SF56A Sample thickness = 5 mm ± 0.2 mm ILIAS MANOLIS 18/10/2016 Slide 17

18 ESA RADGLASS measured total transmission plots for Schott RG645 Sample thickness = 3 mm ± 0.2 mm ILIAS MANOLIS 18/10/2016 Slide 18

19 ESA RADGLASS measured total transmission plots for Schott KG3 Sample thickness = 3 mm ± 0.2 mm ILIAS MANOLIS 18/10/2016 Slide 19

20 ESA RADGLASS measured total transmission plots for Schott N-KF9 Sample thickness = 5 mm ± 0.2 mm ILIAS MANOLIS 18/10/2016 Slide 20

21 ESA RADGLASS measured total transmission plots for Schott N-BALF4 Sample thickness = 5 mm ± 0.2 mm ILIAS MANOLIS 18/10/2016 Slide 21

22 ESA RADGLASS measured total transmission plots for Schott N-LASF41 Sample thickness = 5 mm ± 0.2 mm ILIAS MANOLIS 18/10/2016 Slide 22

23 ILIAS MANOLIS 18/10/2016 Slide 23 Derivation of the Absorption Coefficient (example) ESA RADGLASS extracted absorption coefficient plots for Schott N-PSK53A r t n n r e T T r T t T ad i i i 1, 1 1 and were

24 Conclusions A set of glass materials has been selected for tests. Several campaigns have been conducted and more are expected in the future We only test for total ionizing dose. Attention shall be given when interpreting the results. Dedicated relaxation/annealing measurement campaigns are planned. The raw measurements can be used to perform analysis and support phenomenological models for realistic irradiation (mission-like) conditions. Loss of transmission in some non-radhard glasses is not necessarily a showstopper for given mission profiles and depending on instrument concept. ILIAS MANOLIS 18/10/2016 Slide 24

25 Further reading SPIE 2015 Remote Sensing paper The ESA RADGLASS Portal ILIAS MANOLIS 18/10/2016 Slide 25

26 QUESTIONS? Ref: IPD-HO-ESA-540

27 ESA RADGLASS measured total transmission plots for Schott BK7 G18 Sample thickness = 1 mm ILIAS MANOLIS 18/10/2016 Slide 27