Michael Agamalian

Michael Agamalian

Position: Lead Instrument Scientist

Instrument: Ultra-Small-Angle Neutron Scattering Instrument

Group: Spectroscopy

Division: Chemical and Engineering Materials Division

Facility: Spallation Neutron Source

Contact: magamalian@ornl.gov or (865) 382-6367

Education

PhD in Physics, St. Petersburg Nuclear Physics Institute, Russia

Research

Michael Agamalian and collaborators have made important contributions to the development of the ORNL Bonse-Hart Ultra-Small-Angle Neutron Scattering instrument (USANS). In particular, they adopted the classical X-ray Bonse-Hart technique for neutrons by modifying the Si channel-cut crystal and introducing an additional element, a Cd absorber. This innovation, combined with application of a specialized chemical-mechanical treatment of the diffractive surfaces of the Si channel-cut crystal, has increased the sensitivity of the ORNL USANS instrument by three orders of magnitude. This dramatic improvement of the experimental technique created sufficient conditions for the scientific breakthrough in micron-scale structural analysis using neutron diffraction. Dr. Agamalian has received two international awards for this research, the A. Guinier Prize from the International Union of Crystallography (2002), and the Arnold O. Beckman Award from the International Society of Instrumentation and Control (1999).

Dr. Agamalian has also discovered a new dynamical diffraction effect, the so-called "neutron camel", which refers to the unusual profile of the back-face rocking curve measured on a transparent Si slab-shaped crystal. In combined experimental and theoretical studies, he and his collaborators have identified and investigated the extreme sensitivity of the neutron camel to ultra-small deformation strains (bending with a radius of tens of km), and have demonstrated an application of this effect in the measurement of residual stresses in thin films deposited on thick Si crystals.

The USANS instrument development team led by Michael Agamalian has also developed the concept of a new Time-of-Flight USANS instrument, which is currently under construction at the ORNL Spallation Neutron Source.

Selected Publications

M. Agamalian, J. M. Carpenter, and J. W. Richardson, Validity of the Darwin and Ewald Reflectivity Functions in the Range of Far Wings: Neutron Diffraction Study, Phys. Rev. Lett. In press

M. Agamalian and R. Triolo, The Combined Ultra-Small and Small-Angle Neutron Scattering (USANS/SANS) Technique for Earth Sciences, In Neutron Applications in Earth, Energy, and Environmental Sciences, 567-590 Springer, (2008)

D. W. Schaefer and M. Agamalian, Ultra-Small-Angle Neutron Scattering: A New Tool for Materials Research, Current Options in Solid State & Materials Science 8 39 (2004)

J. M. Carpenter, M. Agamalian, K. C. Littrell, P. Thiyagarajan and Ch. Rehm, Time-of-Flight Implementation of an Ultra-Small-Angle Neutron Scattering Instrument, J. Appl. Cryst. 36 763 (2003)

M. Agamalian, E. Iolin, H. Kaiser, Ch. Rehm, and S. A. Werner, Dynamical Neutron-Scattering Measurements of Residual Stress in a Si Crystal Coated With a Thin Film, Phys. Rev. B 64 161402 (2001)

A.P. Radlinski, E.Z. Radlinska, M. Agamalian, G.D. Wignall, P. Lindner, and O.G. Randl, The Fractal Geometry of Rocks, Phys. Rev. Lett. 82 3078 (1999)

M. Agamalian, C.J. Glinka, E. Iolin, L. Rusevich, and G.D. Wignall, Back-Face Bragg Diffraction from a Perfect and Ultra-Lightly Deformed Thick Crystal, Phys. Rev. Lett. 81 602(1998)

M. Agamalian, G.D.Wignall, and R.Triolo, Optimization of a Bonse-Hart Ultra-Small Angle Neutron Scattering Facility by Eliminating the Rocking Curve Wings, J.Appl.Cryst., 30, 345 (1997)