Abstract
We present a process for thermal forming of thin glass panels of borosilicate glass to produce mirror segments for X-ray telescope optics. The mirror segments are required to be shaped in a parabolic and hyperbolic shape in accordance with Wolter-I type design of X-ray telescope optics. Thermal forming of glass is a low-cost method to produce light-weight mirror segments. The process makes use of a semi-cylindrical quartz mold having surface roughness of the order of 1 nm. Flat glass sheets of 0.2 mm and 0.3 mm thickness are placed on the diametric edges of the mold. With a suitable thermal cycle, the glass sheets are thermally formed as per the shape of the mold. The shape of these formed glass sheets was measured using a non-contact optical setup. The surface quality measurements of the formed glass sheets were performed using atomic force microscope and they were found to be in the range of 0.04–0.33 nm. Once tested for acceptance, these glass sheets are coated using sputter deposition of multi-layers of high and low atomic number materials for hard X-ray reflection. Such mirror segments do not require polishing of the surface before being coated with multi-layers.
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References
Agrawal P C et al. 2017, J. Astrophys. Astron., 38(2), 1
Aschenbach B. 2009, Exp. Astron., 26(1–3), 95
Burrows D. N. et al. 2005, Space Sci. Rev., 120(3), 165
Jansen F., Lumb D., Altieri B., Clavel J., Ehle M., Erd C., Gabriel C., Guainazzi M., Gondoin P., Much R., Munoz R., Santos M., Schartel N., Texier D., Vacanti G. 2001, The Spacecraft and Operations, A&A, 10, 61
Jahoda E. H., Keith; Swank J. H., Giles A. B., Stark M. J., Strohmayer T., Zhang W., Morgan E. H. 1996, Proc. SPIE, 2808, 59
Jimenez-Garate M. A., Charles J. H., William W. C., Finn E. C. 2003, Appl. Optics, 42(4), 724
Koglin J. et al. 2009, NuSTAR Hard X-Ray Optics Design and Performance, in Proceedings of SPIE—The International Society for Optical Engineering 7437
Mao P. 2002, Hard X-Ray Observations of the Extragalactic Sky: The High Energy Focusing Telescope and the Serendipitous Extragalactic X-Ray Source Identification Survey Thesis
Mao P. H., Harrison F. A., Windt D. L., Christensen F. E. 1999, Appl. Optics, 38(22), 4766
Martin C. W., Harvey D. T., Leon P. Van Speybroeck, Stephen L. O’Dell. 2000, Chandra X-Ray Observatory (CXO): Overview, in SPIE 4012, X-Ray Optics, Instruments and Missions III, 2 (July 18, 2000)
Orr J. F., Finlay J. B. 1997, Photoelastic stress analysis in: Optical Measurement Methods in Biomechanics, eds J. F. Orr and J. C. Shelton, Boston, MA: Springer, US, pp. 1–16
Pye L. D., Angelo M., Innocent J. 2005, Properties of Glass-Forming Melts
Sagdeo A. et al. 2010, Exp. Astron., 28(1), 11
Schott A. G., 2013, D 263® T Eco Thin Glass
Serlemitsos P. J., Peter J. et al. 2007, The X-ray telescope onboard Suzaku, Publ. Astron. Soc. Japan, 59(sp1), S9
Singh K. P. et al. 2014, ASTROSAT Mission, in SPIE 9144, Space Telescopes and Instrumentation: Ultraviolet to Gamma Rays
Singh K. P. et al. 2016, In-orbit performance of SXT aboard AstroSat, in: Proceedings SPIE 9905, Space Telescopes and Instrumentation 2016: Ultraviolet to Gamma Ray, 99051E (18 July 2016); https://doi.org/10.1117/12.2235309
Singh K. P. et al. 2017, Soft X-ray focusing telescope aboard AstroSat: Design, characteristics and performance J. Astrophys. Astron., 38(2), Art ID 29
Singh K. P. 2015, AstroSat: India’s First Multi-Wavelength Astronomy Satellite, in National Conference on CICAHEP, Dibrugarh (2015) pp. 1–6
Singh K. P. 2005, Resonance, 10(6), 15
Sørensen B. E. 2014, Eur. J. Mineral., 25(6), 1041
Tanaka Y., Inoue H., Holt S. S. 1994, The X-Ray Astronomy Satellite ASCA, Publ. Astron. Soc. Jpn., 46(3), L37
Wang W et al. 1992, Digital photoelastic analysis of stress distribution in a castable, ceramic crown with different margin designs, in: Experimental Mechanics, ed. E. G. Little, Elsevier, Amsterdam, pp. 467–476
Windt D. L., Waskiewicz W. K., Griffith J. E. 2009, Appl. Optics, 33(10), 2025
Wolter V. H. 1961, Spiegelsysteme Streif Enden Ein f Alls Als Abbildende Optiken Fiir Rijntgenstrarirlen 1, September
Acknowledgements
The authors would like to thank Mr Harshit Shah, Mr Vishwas Risbud, Mr Vilas Mhatre, Mr Jayprakash Koyande and Mr Balu Bagade, the staff of DAA, TIFR, for their contribution in the experimental work carried out in the X-ray laboratory, TIFR. They specially acknowledge the efforts of former staff member of DAA, TIFR, Mr Umesh Tonpe for his valuable contribution in the initial experiments of thermal slumping. They thank Prof. Shriganesh Prabhu and Prof. Venu Gopal Achanta, DCMP, TIFR for providing them with AFM facility in their laboratories time and again. They thank Prof. Pushan Ayyub, DCMP, TIFR for providing the SEM facility in his laboratory. They also thank Ms Bhagyashri Chalke, Mr Rudheer Bapat, Mr John Jesudasan, Mr Vivas Bagwe and Mr Gajendra Mule, staff of DCMP, TIFR and Dr Raghunandan Shukla, DHEP, TIFR for their valuable assistance in handling the SEM and AFM facilities. Finally, they also thank Mr Shirish Pathare, HBCSE, for providing his laboratory facility to perform polarimetric stress measurements for slumped glass sheets.
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Navalkar, V., Singh, K.P. & Press, M. Thermal shaping of thin glass panels for hard X-ray telescope optics. J Astrophys Astron 40, 24 (2019). https://doi.org/10.1007/s12036-019-9592-3
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DOI: https://doi.org/10.1007/s12036-019-9592-3