Skip to main content
Log in

Scatter due to Ultraviolet (UV) photopolymerization of molecular contamination on optical surfaces

  • Original Article
  • Published:
Experimental Astronomy Aims and scope Submit manuscript

Abstract

Molecular contamination on optical surfaces is a serious issue for space payloads. For ultraviolet (UV) payloads, molecular contamination results in loss of throughput. Whereas, for visible (VIS) payloads loss of throughput due to molecular contamination is not very critical. However, UV photopolymerization of molecular contamination can create serious problems to VIS payloads with stringent scatter requirements. Visible Emission Line Coronagraph (VELC) on board ADITYA-L1 mission is one of them. For such payloads, quantifying the effect of molecular contamination in terms of scattered light is very critical. To do the same, UV exposure studies are carried out on optical surfaces with different levels of molecular contamination. Contamination levels are defined by the weight and mass loss of the contaminant. UV dosage levels on the optical surfaces is determined by the number of hours of UV exposure and UV irradiance levels. Variation in the scatter from the optical surfaces is measured pre and post UV exposures. Contaminated optical samples are exposed to the UV radiation levels equivalent to 125 days of mission life. Substantial increase in the scatter of the contaminated samples is observed due to the UV exposure. Increase in scatter is more rapid in the initial mission days (up to 45 days). This paper elaborates the experiments carried out and discusses the results from them.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14
Fig. 15
Fig. 16
Fig. 17
Fig. 18
Fig. 19
Fig. 20

Similar content being viewed by others

References

  1. ASTM: Standard test method fortotal mass loss and collected volatile condensable materials from outgassing in a vacuum environment. Technical report (1993)

  2. Hass, G., Hunter, W.R.: Laboratory experiments to study surface contamination and degradation of optical coatings and materials in simulated space environments. Appl. Opt. 9(9), 2101–2110 (1970)

    Article  ADS  Google Scholar 

  3. Heaney, J.B., Herzig, H., Osantowski, J.F.: Auger spectroscopic examination of mgf2-coated al mirrors before and after uv irradiation. Appl. Opt. 16 (7), 1886–1889 (1977)

    Article  ADS  Google Scholar 

  4. Kent, B.J., Swinyard, B.M., Hicks, D.: Contamination effects on euv optics in the space environment. In: Proceedings Space Astronomical Telescopes and Instruments II, p 1945 (1993)

  5. Kumar, N., Prasad, B., Singh, J., Venkata, S.: Optical design of visible emission line coronagraph on indian space solar mission aditya-l1. Exp Astron (2018)

  6. Prasad, B.R., Banerjee, D., Singh, J., Nagabhushana, S., Kumar, A., Kamath, P.U., Kathiravan, S., Venkata, S., Rajkumar, N., Natarajan, V., Juneja, M., Somu, P., Pant, V., Shaji, N., Sankarsubramanian, K., Patra, A., Venkateswaran, R., Adoni, A., Narendra, S., Haridas, T.R., Mathew, K.S., Mohan, K., Amareswari, K., Jaiswal, B.: Visible emission line coronagraph on Aditya-L1. Curr. Sci. 113, 613–615 (2017)

    Article  ADS  Google Scholar 

  7. Singh, S., Singh, R.: High-altitude clear-sky direct solar ultraviolet irradiance at leh and hanle in the western himalayas: Observations and model calculations. J. Geophys. Res. Atmos. (1984–2012) 109(D19) (2004)

  8. Suresh V., Raghavendra P.B., Natarajan V., Umesh K.P., Kathiravan S.: Band-limited integrated scatter measurements on super polished optical mirrors. Opt. Eng. 59(8), 084106 (2020). https://doi.org/10.1117/1.OE.59.8.084106

  9. Tveekrem, J.: Contamination Effects on Euv Optics. Goddard Space Flight Center, Greenbelt, MD (1999)

  10. Venkata, S.N., Prasad, B.R., Nalla, R.K., Singh, J.: Scatter studies for visible emission line coronagraph on board aditya-l1 mission. J. Astron. Telesc. Instrum. Syst. 3 (2017)

  11. Whitlock, L.A., Jackson, J.L.: Pearlss: a model for contamination effects–description and results, p 1753 (1993)

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Venkata Suresh Narra.

Additional information

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Narra, V.S., Budihal, R.P., Somasundaram, P.K. et al. Scatter due to Ultraviolet (UV) photopolymerization of molecular contamination on optical surfaces. Exp Astron 50, 265–287 (2020). https://doi.org/10.1007/s10686-020-09675-8

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10686-020-09675-8

Keywords

Navigation