by Karen Richardson
The search for dark matter in the universe is an important one. "From what we know, 85% of the matter in the universe is dark matter," says Wolfgang Rau, Professor in the Department of Physics, Engineering Physics and Astronomy. "We know it's there from gravitational effects, but we have no clue what it is. If we could identify these particles, it would be a huge advance in knowledge, as its most of what this universe is made of. It's an important question for the fundamental understanding of particle physics and cosmology in general."
Professor Rau's area of expertise is the field of astro-particle physics (he is a Canada Research Chair) and he is currently involved in the Cryogenic Dark Matter Search to try to find dark-matter particles, an experiment which is dominated by U.S. scientists. "We are presently running the experiment in an underground laboratory in northern Minnesota, the Sudan Underground Laboratory." Professor Rau says they have just completed their newest results of the dark-matter search, which they are planning to submit for publication. "Now we are again leading the field. We plan to increase our detector - at the moment we are running about 5 kg of detector mass - and we want to increase that to 25 kg, which requires a completely new experimental set-up."
The research team is planning to move to the new SNOLAB in Sudbury, Ont. that was built in an active nickel mine. This will allow them to take advantage of increasing their target mass as the interfering cosmic radiation is reduced as they move deeper underground. Professor Rau is planning to set up a facility at Queen's to test detectors before they are deployed in the final experiment. "Graduate students in the group would work on running the test facility and detectors but would also go to the underground laboratory to help run the experiment itself and analyze data," he says.
Professor Rau received his PhD from the University of Heidelberg in Germany and he worked at the Max Planck Institute for Nuclear Physics in Heidelberg, where he studied neutrino physics. He completed a post-doctoral degree at the University of California, Berkeley and as a Researcher at the Technical University in Munich, Germany. He currently teaches Introduction to Quantum Mechanics as well as Nuclear and Particle Physics at Queen's.
Commenting on his teaching style, he says it is important for graduate students to be self-motivated, rather than simply learning information for the exam. "I try to teach in a way that gives students the chance to understand the basic ideas of underlying physics, which I think is much more important than just being able to solve equations." He adds that acquiring a Master's or PhD title should not be the sole motivation of students, especially for experimental physics, where planned experiments are often not successful. "Often you spend weeks or months preparing something and then it doesn't work as planned. In the end there is a big reward if, after several trials, you do a nice measurement and find a good result, but you need patience and tolerance for frustrating events."
Unique to the department at Queen's is the close connection between physics and engineering sciences. "The department is relatively small compared to other departments where I have worked, but in general it is a very good atmosphere and a constructive research environment," says Professor Rau.