Dr Hal Lee

Phone: +61 (2) 9717 7149
Email: WaiTung.Lee@ansto.gov.au

Hal leads the Institute's Helium-3 Polarisation Project. The project will bring polarised Helium-3 based neutron polarisers and analysers to several new instruments, including PELICAN, PLATYPUS, QUOKKA, WOMBAT, SIKA, and possibly TAIPAN. His research interests are in the areas of polarised Helium-3 application in neutron scattering works, magnetic thin film physics, magnetic structures and magnetic excitations in materials, and high-resolution measurement techniques in biology and chemistry.

His technical expertise includes polarised Helium-3 production and the application to neutron scattering work, polarised neutron scattering (reflectometry, inelastic scattering, diffraction), instrumentation (spin-echo resolved grazing-incident scattering, reflectometer, neutron optics and guides, self-shielded asymmetric high-field superconducting magnets, Monte Carlo simulation of neutron scattering instruments), neutron interferometry, and UHV thin-film deposition and characterisation techniques.

Qualifications and Achievements:

• 40+ refereed research articles in scientific journals and 1 book chapter;
• 60+ presentations in conferences and workshops, including invited talks on polarised Helium-3 R&D and polarised neutron scattering work;
• Co-chaired International Conference on Polarized Neutrons in Condensed Matter Investigations 2004;
• Led teams to develop hybrid asymmetric magnet, spin+/spin- switchable polarised Helium-3 based neutron spin filter, split-beam Littrow cavity for high-power laser spectrum narrowing. Developed polarised neutron reflectometry technique to measure magnetic domain dispersion, Monte Carlo simulation software for neutron scattering instrumentation Design "IDEAS";
• Jointly developed successful Small Business Innovation Research Grant (US DOE) applications with R&D companies in the development of superconducting magnets (2005) and large capacity polarised Helium-3 filling station (2008, 2009);
• Ph.D. in Physics, University of Missouri-Columbia, 1998.

Selected Publications

"In-situ Polarized ³He-Based Neutron Polarization Analyzer for SNS Magnetism Reflectometer", W.-T. Lee, X. Tong, J. Pierce, M. Fleenor, A. Ismaili, J.L. Robertson, W.C. Chen, T.R. Gentile, A. Hailemariam, R. Goyette, A. Parizzi, V. Lauter, F. Klose, H. Kaiser, C. Lavelle, D.V. Baxter, G.L. Jones, J. Wexler, and L. McCollum, Journal of Physics, accepted for publication (2009).

"Increasing the Pump-Up Rate To Polarize ³He Gas Using Spin-Exchange Optical Pumping Method", W.T. Lee, X. Tong, D. Rich, Y. Liu, M. Fleenor, A. Ismaili, J. Pierce, M. Hagen, J. Dadras, J.L. Robertson, Physica B 404, 2670 (2009).

"Birefringent Neutron Prisms or Spin Echo Scattering Angle Measurement", R. Pynn, M.R. Fitzsimmons, W.T. Lee, P. Stonaha, V.R. Shah, A.L. Washington, B.J. Kirby, C.F. Majkrzak, and B.B. Maranville, Physica B 404, 2582 (2009).

"The use of symmetry to correct Larmor phase aberrations in spin echo scattering angle measurement", R. Pynn, W.T. Lee, P. Stonaha, V.R. Shah, A.L. Washington, B.J. Kirby, C.F. Majkrzak, and B.B. Maranville, Review of Scientific Instruments 79, 063901, (2008).

"Test of a continuously polarized He-3 neutron spin filter with NMR-based polarization inversion on a single-crystal diffractometer", G.L. Jones, F. Dias, B. Collett, W.C. Chen, T.R. Gentile, P.M.B. Piccoli, M.E. Miller, A.J. Schultz, H. Yan, X. Tong, W.M. Snow, W.T.Lee, C. Hoffmann, J. Thomison, Physica B 385-86, 1131 (2006).

"Magnetic Properties of uniaxial synthetic antiferromagnets for spin-valve applications", Zhiya Zhao, P. Mani, G. J. Mankey, G. Gubbiotti, S. Tacchi, F. Spizzo, W.-T. Lee, C.T. Yu, M.J. Pechan, Physical Review B 71, 104417 (2005).

"Measuring Lateral Magnetic Structures in Thin Films Using Time-of-Flight Polarized Neutron Reflectometry", W.-T. Lee, F. Klose, H. Q. Yin, and B. P. Toperverg, Physica B, 335, 77 (2003).

"Ferromagnetic domain distribution in thin films during magnetization reversal", W.-T. Lee, S. G. E. te Velthuis, G. P. Felcher, F. Klose, T. Gredig, and E. D. Dahlberg, Physical Review B 65, 224417 (2002).

"SNS magnetism reflectometer: basic design and neutron guide optimization using Monte Carlo simulations", W.-T. Lee and F. Klose, Proceedings of SPIE, 4509, 145 (2001).

"Observation of scalar Aharonov-Bohm effect with longitudinally polarized neutrons", W.-T. Lee, O. Motrunich, B. E. Allman, and S. A. Werner, Physical Review Letters 80, 3165 (1998).

"A new neutron Polarizer for Neutron Interferometry Experiments", W.-T. Lee, O. Motrunich, B. E. Allman, and S. A. Werner, Journal of the Physical Society of Japan 65, Supplement A, 210 (1997).