Applied Physics

Physics, the original interdisciplinary science, has a host of applications in many areas of immediate interest and relevance to society. Ion beam analysis techniques such as PIXE and RBS, based on a 3 MV accelerator, are used to study content and structure of environmental samples and hi-tech devices and materials. Medical physics projects employ atomic and nuclear techniques to measure toxic trace elements in the body in the context of occupational health; a system for assessing bone Sr content is being developed. Atomic and nuclear techniques also underpin the development and application of X-ray analysis methods for geochemical exploration of planetary surfaces, through the MER, MSL, and future space missions.

Back to Top ^

Astrophysics and Gravitation

Dumbbell Nebula

The Guelph Gravitation Group is led by two faculty members, Luis Lehner and Eric Poisson; the group includes a number of graduate students and post-doctoral fellows. Our aim is to understand the nature of gravitation in its most extreme manifestations predicted by Einstein's theory of general relativity. This understanding has a theoretical component (how does one solve the equations to extract the phenomena?) and an observational component (how does one measure the phenomena?). Our interests are in the theoretical aspects of gravitation at its interface with astrophysics; we aim to make predictions that guide the observers. Gravity is at its most extreme when bodies are massive and compact; we therefore study neutron stars and black holes, as well as more exotic objects such as boson stars and black strings. The physics of compact objects involves more than just gravity; it is rich in other aspects such as magnetohydrodynamics, nuclear physics, and exotic field theories. We are interested in every aspect of the physics of compact objects, including their internal structure and the way they dynamically interact with companion bodies. An important component of our work is concerned with the ongoing efforts to measure gravitational waves using earth-based detectors (now operational) and space-based detectors (in development). Gravitational waves are produced when large masses are accelerated to high speeds; binary systems of compact objects are among the most promising sources. With our work we aim to improve our understanding of such systems, and refine our predictions regarding the form that the gravitational-wave signals will take. Given the difficulty of integrating the Einstein field equations for these purposes, several avenues offer themselves. One can rely on approximations and develop pen-and-paper techniques to solve the equations. This approach is optimal when, for example, a binary system has a very small mass ratio, or when the orbital velocity is small compared with the speed of light. When the approximations fail, however, one must face the task of integrating the field equations on a supercomputer. Our work covers all these situations, and our individual web pages offer additional details. We enjoy close associations with Perimeter Institute for Theoretical Physics, the Canadian Institute for Theoretical Astrophysics, and the Canadian Institute for Advanced Research.

Back to Top ^

Atomic, Molecular and Optical Physics

Atomic, Molecular and Optical Physics is a broad interdisciplinary field, with applications in biophysics, medicine, astrophysics, cryogenics, chemistry, environmental science and information processing. Our facilities consist of state-of-the-art equipment, which include some of the world`s most intense lasers, a new 3MV accelerator, and the world`s first confocal scanning laser microscope, and Canada`s only scanning proton microprobe. Many interesting opportunities are also available for theoretical research in this area, and include formal work in variational calculus and boundary value problems, molecular collision theory, ion channel studies, quantum and classical chaos, theory of femtosecond laser interaction with atoms and molecules, coherent control of quantum dynamics, computer simulations of biophysical transport processes, and the calculation of atomic transition rates used in in astrophysical plasma modelling and spectral analysis.

Back to Top ^

Biophysics

Solid-state Nuclear Magnetic Resonance can be used to measure interatomic distances and to determine protein structure at atomic resolution

Biophysics is an interdisciplinary science in which the ideas and techniques of physics are applied to gain understanding of biological systems. At Guelph, we study a broad range of problems in biological and medical physics including fundamental aspects of protein structure and function, the physical properties of cell membranes and protein:membrane interactions, assemblies of macromolecules, and non-invasive elemental analysis medical applications. Guelph biophysicists make use of the most up-to-date techniques available, including neutron scattering, nuclear magnetic resonance, X-ray diffraction, vibrational spectroscopy, atomic force microscopy and molecular modeling.

Back to Top ^

Chemical Physics

The interplay between physics and chemistry constitutes one of the most interesting blends of pure and applied research today. Our experimentalists are at the forefront of this research, performing some of the most precise spectroscopic measurements in the world and detecting phenomena as exotic as water on the sun. A variety of advanced techniques are employed in this work, including thin film preparation, Fourier Transform Infrared Spectroscopy, High Resolution Photoionization, Nuclear Magnetic Resonance and Field measurements of atmospheric clouds. There is ample opportunity for theoretical work as well in statistical mechanics, non-equilibrium thermodynamics, the determination of intermolecular forces many-body theory, density functional theory and various mathematical modelling techniques.

Back to Top ^

Condensed Matter and Material Physics

Condensed matter physics, with its inexhaustible wealth of theoretical concepts and experimental applications, forms the largest branch of physics research today. Our experimentalists probe the most novel properties of fluids, crystals, gels, macromolecules, semiconductors, and metals, in order to determine the collective behaviour of matter under as broad a range of circumstances as possible. Our theorists work closely with their experimental colleagues to understand phenomena as diverse as high-temperature superconductivity, spin-glasses, glass transitions, chemisorption, vortices, surface and interfacial phenomena, structure of polymers and proteins, and critical phenomena. With numerous applications in lubrication, batteries, logic circuits and plasmas, our investigations into condensed matter present students with perhaps the broadest range of career alternatives in physics.

Back to Top ^

Nanoscience

Square patterns for heated polymer film

A dramatic transformation in science and technology is happening. The next fifty years will see new inventions, novel products, stunning medical advances, remarkable energy solutions, and creative answers to controlling and understanding technological and biological processes - and nanoscience is making them all possible. Our nanoscience researchers use a wide range of state-of-the-art experimental and computational techniques for studies of matter on the nanoscale, ranging from the self-assembly of polymers to the optical properties of single sheets of graphite called graphene to the mechanical properties of unique biomaterials derived from bacteria. Exciting opportunities exist for students to get involved in graduate research as well as academic studies in our new B.Sc. Nanoscience degree program.

Back to Top ^

Physics Education

The four faculty members who have a particularly strong interest in Physics Education - Ernie L. McFarland, Joanne M. O'Meara, and Martin Williams - are involved in a variety of activities and projects. These include participation in curriculum development at the University of Guelph, as well as at the provincial and national levels. There is also interest in exploring and evaluating new interactive lecturing methods, developing effective lecture demonstrations and laboratory experiments, using sports and music in physics teaching, creating teaching materials for elementary school teachers, and giving physics-demonstrations presentations to the general public and school groups in person and on television.

Back to Top ^

Planetary Surface Exploration

Mars Exploration Rover
Credit: NASA / JPL / Maas

Faculty member Ralf Gellert is currently the lead scientist for the Alpha-Particle X-ray Spectrometer (APXS) on board the Mars Exploration Rovers (MER). Together with a team of scientists from the Max-Planck Institute in Mainz, the Jet Propulsion Lab and NASA we are performing the daily operations of the instruments on Mars and analyzing the returned data. The APXS is one of the analytical instruments mounted on the rover arm. It measures the chemical composition of rocks and soils with x-ray spectroscopy. Since the successful landing on Mars in January 2004 the rovers Spirit and Opportunity returned more than 100 APXS measurements from each site along their traverse of nearly 5 kilometers. Results of the APXS on both landing sites contributed to the findings of MER that water played a major role during the formation of the encountered rocks and soils. In collaboration with the group of Prof. Iain Campbell we are improving the theoretical model for the data analysis. The APXS uses alpha particles and x-rays from radioactive sources to excite characteristic elemental radiation. The GUPIX package for PIXE (Proton induced X-ray Emission) will be extended to include both of these excitation modes.

Back to Top ^

Subatomic Physics

Prof. Carl Svensson at TRIUMF, working with graduate student Bronwyn Hyland on the 8pi gamma-ray spectrometer

Subatomic physics is the study of the constituents of matter on the scale of the atomic nucleus, and smaller, and their interactions. Our primary experimental efforts are centered on nuclear structure, nuclear astrophysics, and searches for physics beyond the Standard Model using Canada's world-leading radioactive beam facilities, ISAC and ISAC-II, located in Vancouver at TRIUMF. Major experimental facilities at TRIUMF operated by us include the TIGRESS and 8pi gamma-ray spectrometers, and we are currently developing the DESCANT array of neutron detectors. Our research also includes experimental work performed at world-leading laboratories worldwide, including the Maier-Leibnitz Laboratory at Munich, the Van de Graaff Accelerator facility in Lexington, Kentucky, and Argonne National Laboratory near Chicago. Our theoretical efforts concentrate on obtaining predictions of neutrino interactions relevant to SNO, the Sudbury Neutrino Observatory, as well as with furthering the development, understanding and predictions of the quark model of baryons.

Back to Top ^