Prof Ghassan Yassin
Senior Research Fellow in Astrophysics
I presently teach the 'Astrophysics Laboratory' for Physics students where we teach them how to process astronomical data from space and ground based telescopes, lecture the first year PhD students in Astrophysics and supervise an MPhys project. At Queen's I give tutorials in 'Electromagnetism and Optics' for the second year Physics and 'Special Relativity' for the third year.
My research group is part of the Astrophysics sub-department whose work spans most areas in Astrophysics. It typically consists of two postdoctoral research associates, two PhD students and electronics technicians. We have a state of the art cryogenic laboratory where we develop superconducting detectors with quantum-limited sensitivity and other quasi-optical and superconducting devices. These detectors and devices are used in astronomical receivers installed at the focal plane of radio-telescopes to explore the evolution of stars and galaxies or used in cosmology instruments to investigate the properties of the Cosmic Microwave Background. Our work requires thorough understanding of the physics of quantum detection above the superconducting gap, electromagnetic propagation in planar superconducting structures and of course the astronomy we aim to observe. We are funded by research grants from national and European councils.
Yassin, G., Robson, M. and Dffett-Smith, P. J., (1993): “The electrical characteristics of a conical horn-reflector antenna employing a corrugated horn,” IEEE Trans. Antenna Propagat., AP–41, pp. 357
Robson, M., Yassin, G., Woan, G., Wilson, D. M. A., Scott, P. F., Lasenby, A. N., Kenderdine, S., and Duffett-Smith, P. J., (1993): “The Cosmic Anisotropy Telescope,” Astron. Astrophys., 277, 314-320.
Yassin, G. and Wthington, S., (1995): “Electromagnetic models for superconducting millimetre-wave and submillimetre-wave microstrip transmission line,” J. Phys. D: Appl. Phys., 28, pp. 1983–1991.
O’Sullivan, C., Yassin, G., Woan, G., Scott, P. F., Saunders, R., Robson, M., Pooley, G., Lasenby, A. N., Jones, M., Hobson, M. P., and Duffett-Smith, P. J., (1995): “A search for primordial anisotropies in the CMBR: first observations at 13.5 GHz with the CAT,” Mon. Not. R. Astron. Soc., 274, pp. 861–868.
Yassin, G., and Withington, S., (1996): “Analytical expression for the input impedance of a microstrip probe in waveguide,” International Journal of Infrared and Millimetre Waves, 17, pp. 1685-1705.
Yassin, G., Withington, S., Jacobs, K. and Wulff, S., (2000): “A 350 GHz antipodal finline mixer,” IEEE Trans. Microwave Theory Tech, MTT-48, pp. 662-669.
Withington, S., Yassin, G. and Murphy, J. A., (2000): “Dyadic analysis of partially coherent submillimetre-wave antenna systems,” IEEE Trans. Antenna Propagat., AP-49, pp. 1226-1234
Yassin, G., Jung, G., Dikovsky, V., Barboy, I. Kambara, M. and Cardwell, D. A. and Withington, S., (2001): “Investigation of microwave propagation in high-temperature superconducting waveguides,” IEEE Microwave and Guided Waves Letters, vol. 11, 10, 413
Withington, S., and Yassin, G., (2001): “Power-Coupled between partially coherent vector fields in different states of coherence,” J. Optical Society America A, vol. 18, 12, pp. 3061- 3071.
Yassin, G., Dikovsky, V., Barboy, I. Kambara, M., Cardwell, D. A., Withington, S. and Jung, G., (2001): “Microwave transmission through high-temperature superconducting waveguides,” Physica C: Superconductivity and Applications, vol. 372-376, pp. 523-525.
Dicker, S., Yassin, G. and Withington, S., (2002): “A two-element horn-reflector antenna interferometer for the cosmic microwave background Astronomy,” IEEE Trans. Antenna Propagat.,AP-50, 198
Withington, S., Campbell, E., Yassin, G., and Tham, C. Y. (2003) “Beam combining superconducting detector for submillimetre-wave interferometric astronomy’ ’ Electronics Letters vol. 39 No. 7, pp. 605
Kittara, P., Withington, S., and Yassin, G. (2003) “Multitone quantum simulations of saturating tunnel junctions mixers’’ J. Appl. Phys. Vol. 93(12), pp. 9812-9822.
Yassin, G. et al (2004): “ CLOVER: The CMB Polarization Observer)’’ Proceedings of the 15th International Symposium on Space Terahertz Technology, April 27-29, UMASS, USA.
R. Barker, et al (2005): “High-significance Sunyaev-Zel'dovich measurement: Abell 1914 seen with the Arcminute Microkelvin Imager” Mon. Not. R. Astron. Soc. Vol. 369 (1), pp. L1-L4.
Taylor, A. C. et al (2006): Clover: “A B-mode polarization experiment,” New Astron. Rev. 50, 993-998.
North, C. E., et al (2007): “CLOVER – Measuring the CMB B-mode Polarization,” Proc. 18th, Int. Symposium on Space Teraherz Technology, 23-25 March, Pasadena, USA
Yassin,G., Kuzmin, L. S., Grimes, P., Tarasov, M., Otto, E. and Mauskopf, P. D. (2007) “An Integrated Superconducting Phase Switch for Cosmology Instruments” Physica C: Applied Superconductivity and Application, vol. 466 (issue 2) pp. 115-123
Grimes, P. K., King, O., G., Yassin, G., and Jones, M. E. (2007): “Compact broadband planar orthomode transducer,” Electron. Lett., vol. Volume 43, Issue 21, p. 1146-1148
Zwart, J. et al (2008): “The Arcminute Microkelvin Imager” Monthly Notices of the Royal Astronomical Society, vol. 391, pp. 1545-1558.
Yassin, G.; Grimes, P.K.; King, O.G.; North, C.E. (2008): “Waveguide-to-planar circuit transition for millimetre-wave detectors,” Electron. Lett. vol. 44, pp. 866.
Buckle, J.V., Hills, R.E., Smith, H., et. al. (2009): “HARP/ACSIS: a submillimetre spectral imaging system on the James Clerk Maxwell Telescope,” Monthly Notices of the Royal Astronomical Society, vol. 399 , pp. 1026-1043.
Leech, J., Tan, B. –K., Yassin, G., Kittara, P., and Wangsuya, S., Treuttel,, J., Henry, M., Oldfield, M., L., and Huggard, P., (2011): “ Multiple flare-angle feeds for submillimetre astronomy and Cosmic Microwave Background Experiments, “ Astron.& Astrophys., vol. 532, A61+
Tan, B. –K. and Yassin, G. (2011): “Josephson Pair Tunnelling Influence on the Performance of an SIS mixer Near its Superconducting Gap,” International Journal of Terahertz Science and Technology vol. 4, pp. 123-127.
Tan, B. –K. Yassin, G., Grimes, P., Leech, J., Jacobs, K., and Groppi, C., (2012): “ A 650 GHz unilateral finline SIS mixer fed by a multi-flare angle smooth-walled horn,” IEEE Trans. Terahertz Science and Technology, vol. 2 (1), pp. 40-49
Leech, J., Tan, B. –K., Yassin, G., Kittara, P., and Wangsuya, S., (2012): “ Experimental investigation of a low cost, high performance focal-plane feed array “ IEEE Trans. Terahertz Science and Technology, vol. 2 (1), pp. 61-70.
B.-K. Tan, G. Yassin, P. Grimes, and K. Jacobs, “650 GHz SIS mixer fabricated on silicon-on- insulator substrate,” Electronics Letters, vol. 49, no. 20, pp. 1273–1275, 2013.
B.-K. Tan, G. Yassin, P. Grimes, K. Jacobs, and S. Withington, “Preliminary Measurement Results of a 650 GHz Planar Circuit Balanced SIS Mixer,” IEEE Transactions on Terahertz Science and Technology, vol. 3, no. 1, pp. 32–38, 2013.
P. K. Grimes et al, “ Instrumentation with single-dish observation with the Greenland Telescope” in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series , Canada , 22-27 June ,2014.
B.-K. Tan, G. Yassin and P. K. Grimes, “Ultra-Wide Intermediate Bandwidth for High-Frequency SIS Mixers” IEEE Transactions on Terahertz Science and Technology, vol. 4, pp. 165-170, March, 2014.