Geant4 simulations of a wide-angle x-ray focusing telescope

Abstract

The rapid development of X-ray astronomy has been made possible by widely deploying X-ray focusing telescopes on board many X-ray satellites. Geant4 is a very powerful toolkit for Monte Carlo simulations and has remarkable abilities to model complex geometrical configurations. However, the library of physical processes available in Geant4 lacks a description of the reflection of X-ray photons at a grazing incident angle which is the core physical process in the simulation of X-ray focusing telescopes. The scattering of low-energy charged particles from the mirror surfaces is another noteworthy process which is not yet incorporated into Geant4. Here we describe a Monte Carlo model of a simplified wide-angle X-ray focusing telescope adopting lobster-eye optics and a silicon detector using the Geant4 toolkit. With this model, we simulate the X-ray tracing, proton scattering and background detection. We find that: (1) the effective area obtained using Geant4 is in agreement with that obtained using Q software with an average difference of less than 3%; (2) X-rays are the dominant background source below 10 keV; (3) the sensitivity of the telescope is better by at least one order of magnitude than that of a coded mask telescope with the same physical dimensions; (4) the number of protons passing through the optics and reaching the detector by Firsov scattering is about 2.5 times that of multiple scattering for the lobster-eye telescope.

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Notes

  1. 1.

    Q software is available from the author by request email zrw@le.ac.uk

  2. 2.

    http://henke.lbl.gov/optical_constants/layer2.html

  3. 3.

    http://henke.lbl.gov/optical_constants/getdb2.html

  4. 4.

    http://physics.nist.gov/PhysRefData/Star/Text/PSTAR.html

  5. 5.

    ftp://ftp.xray.mpe.mpg.de/rosat/catalogues/rass-bsc/

References

  1. 1.

    Zhang, S. -N.: China’s first dedicated astronomy satellite: the hard x-ray modulation telescope (HXMT). AAS 41, 474 (2009)

    ADS  Google Scholar 

  2. 2.

    Yuan, W., Zhang, C., Feng, H., et al.: Einstein Probe — a Small Mission to Monitor and Explore the Dynamic X-ray Universe. La Sapienza University, Rome, Italy (2014)

    Google Scholar 

  3. 3.

    Zhao, D., Zhang, C., Yuan, W., et al.: Ray tracing simulations for the Wide-field X-ray Telescope of the Einstein Probe mission based on Geant4 and XRTG4. SPIE, 9144 (2014)

  4. 4.

    Yuan, W., Osborne, J.P., ZHang, C., Willingale, R.: Exploring the Dynamic X-ray Universe: Scientific opportunities for the einstein probe Mission[J]. J. Spat. Sci. 36(2), 117–138 (2016)

    Google Scholar 

  5. 5.

    Wolter, H.: Spiegelsysteme streifenden Einfalls als abbildende Optiken für röntgenstrahlen. AnP 445, 94–114 (1952)

    ADS  MATH  Google Scholar 

  6. 6.

    Angel, J. R. P.: Lobster eyes as X-ray telescopes. ApJ 233, 364–373 (1979)

    ADS  Article  Google Scholar 

  7. 7.

    Agostinelli, S., 127 colleagues: GEANT4—A simulation toolkit. NIMA 506, 250–303 (2003)

    ADS  Article  Google Scholar 

  8. 8.

    Fraser, G. W., Brunton, A. N., Lees, J. E., et al.: X-ray focusing using square-pore microchannel plates First observation of cruxiform image structure. NIMPA 324, 404–407 (1993)

    ADS  Article  Google Scholar 

  9. 9.

    Benkhoff, J., van Casteren, J., Hayakawa, H., et al.: BepiColombo—Comprehensive exploration of Mercury: Mission overview and science goals. Planet. Space Sci. 58, 2–20 (2010)

  10. 10.

    Fraser, G.W., Carpenter, J.D., Rothery, D.A., et al.: The mercury imaging X-ray spectrometer (MIXS) on bepicolombo. Planet. Space Sci. 58, 79–95 (2010)

    ADS  Article  Google Scholar 

  11. 11.

    Buis, E. J., Vacanti, G.: X-ray tracing using Geant4. NIMA 599, 260–263 (2009)

    ADS  Article  Google Scholar 

  12. 12.

    Short, A. D., Ambrosi, R. M., Hutchinson, I. B., et al.: Performance of the Swift X-ray Telescope (XRT) Mirror/Detector Combination. AIPC 662, 511–513 (2003)

    ADS  Google Scholar 

  13. 13.

    Spaan, F. H. P., Willingale, R.: The point spread function of silicon pore x-ray optics. SPIE, 7011 (2008)

  14. 14.

    Martindale, A., 18 colleagues: The Mercury Imaging X-ray Spectrometer: optics design and characterisation. SPIE 7441, 744117 (2009)

    Google Scholar 

  15. 15.

    Willingale, R., Fraser, G. W., Brunton, A. N., et al.: Hard X-ray imaging with microchannel plate optics. ExpA 8, 281–296 (1998)

    Google Scholar 

  16. 16.

    Prigozhin, G. Y., Kissel, S. E., Bautz, M. W., et al.: Radiation damage in the Chandra x-ray CCDs. SPIE 4012, 720–730 (2000)

    ADS  Google Scholar 

  17. 17.

    Dichter, B. K., Woolf, S.: Grazing angle proton scattering: effects on chandra and xmm-newton x-ray telescopes. ITNS 50, 2292–2295 (2003)

    ADS  Google Scholar 

  18. 18.

    Turner, M.: A magnetic diverter for Charged Particles on XEUS ESA document SCI-SA/AP/06/0412cv (2006)

  19. 19.

    Prepared by the XMM-Newton Community Support Team with contributions from the entire XMM-Newton Science Operations Centre Team, XMM-Newton Users Handbook, Issue 2.13, 20.07. 2015

  20. 20.

    Willingale, R.: An electron diverter for the Swift Telescope, XRA study note XRT-LUX-RE-011/1 University of Leicester (2000)

  21. 21.

    Burrows, D. N., Hill, J. E., Nousek, J. A., et al.: The Swift X-Ray Telescope. SSRv 120(3-4), 165–195 (2005)

    ADS  Google Scholar 

  22. 22.

    Lei, F., Nartallo, R., Nieminen, P., et al.: Update on the use of geant4 for the simulation of Low-Energy protons scattering off X-Ray mirrors at grazing incidence angles. ITNS 51, 3408–3412 (2004)

    ADS  Google Scholar 

  23. 23.

    Firsov, O. B.: Reflection of fast ions from a dense medium at glancing angles. Sov. Phys. Dokl. 11, 732 (1967)

    ADS  Google Scholar 

  24. 24.

    Nartallo, R., Daly, E., Evans, H., et al.: Low-angle scattering of protons on the XMM-newton optics and effects on the on-board CCD detectors. ITNS 48, 1815–1821 (2001)

    ADS  Google Scholar 

  25. 25.

    Petrov, A.N., Grigoryan, O.R., Panasyuk, M.I.: Energy spectrum of proton flux near geomagnetic equator at low altitudes. AdSpR 41, 1269–1273 (2008)

    ADS  Google Scholar 

  26. 26.

    Hiroshi, T., Masaru, M., Shiro, U., et al.: Cosmic-ray background simulation for the CCD camera (SSC) of the MAXI mission onboard the International Space Station. Proc. SPIE 4851, 993 (2003)

    Article  Google Scholar 

  27. 27.

    Zhao, D., Cordier, B., Sizun, P., et al.: Influence of the Earth on the background and the sensitivity of the GRM and ECLAIRs instruments aboard the Chinese-French mission SVOM. ExpA 34, 705–728 (2012)

    Google Scholar 

  28. 28.

    Campana, R., Feroci, M., Del Monte, E., et al.: Background simulations for the Large Area Detector onboard LOFT. ExpA 36, 451–477 (2013)

    Google Scholar 

  29. 29.

    Miyaji, T., Ishisaki, Y., Ogasaka, Y., et al.: The cosmic X-ray background spectrum observed with ROSAT and ASCA. A&A 334, L13–L16 (1998)

    ADS  Google Scholar 

  30. 30.

    Barthelmy, S. D., Barbier, L. M., CUMMINGS, J. R., et al.: The Burst Alert Telescope (BAT) on the Swift MIDEX mission. SSRv 120, 143–164 (2005)

    ADS  Google Scholar 

  31. 31.

    Voges, W., 19 colleagues: The ROSAT all-sky survey bright source catalogue. A&A 349, 389–405 (1999)

    ADS  Google Scholar 

Download references

Acknowledgments

This work is supported by the Strategic Priority Research Program on Space Science, the Chinese Academy of Sciences, Grant No. XDA04061100, the programs of National Natural Science Foundation of China under the Grant No.11403055, No.11203043 and No.11427804, China Post-doctoral Science Foundation under the Grant No.2014M561068, and the Young Researcher Grant of National Astronomical Observatories, Chinese Academy of Sciences.

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Correspondence to Donghua Zhao.

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Zhao, D., Zhang, C., Yuan, W. et al. Geant4 simulations of a wide-angle x-ray focusing telescope. Exp Astron 43, 267–283 (2017). https://doi.org/10.1007/s10686-017-9534-5

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Keywords

  • X-ray telescope
  • Geant4
  • Lobster-eye optics
  • Scattering of charged particles
  • Background
  • Sensitivity