Dr. Norbert Thonnard

Director, Institute for Rare Isotope Measurements, and Research Professor, Departments of Geological Sciences, and Physics and Astronomy
Email: nthonnar@utk.edu

Research Interests

Although my training was in atomic and molecular physics, I have always been keenly interested in applying physics principles and techniques to other areas of the physical sciences, and occasionally, even to the biological sciences.

I have been fortunate in my professional career of being at organizations that have brought together scientists from a wide variety of disciplines and have enjoyed experiencing the synergism that can develop in such an environment. Before joining the University of Tennessee in 1993, I spent 13-years at the Department of Terrestrial Magnetism of the Carnegie Institution of Washington and 10 years at Atom Sciences, Inc., a high-tech spin-off from Oak Ridge National Laboratory. These were years of very rapid developments in the astronomical and geological sciences, and my research evolved from studies of interstellar molecules, to elucidation of galaxy dynamics, to detection of just a few atoms of a particular isotope, all of which resulted in close collaboration with scientists from many fields. My collaborators have been very patient teachers, and have enabled me to participate in some of the very exciting new developments in areas as diverse as hydrogeology and early solar system studies.

The Institute for Rare Isotopes Measurements (IRIM) was started at UT to exploit new research directions made possible by the development of extremely sensitive analytical techniques using multiple lasers that make detection of only a few atoms in a sample feasible. We are collaborating with researchers word-wide, applying our expertise to studies of very old groundwater, contaminant transport and modern groundwater recharge, age-dating of polar ice sheets, and to studies of isotopic signatures in minute mineral grains in meteorites and presolar dust grains to understand the formation and early history of our solar system. The research at IRIM has been funded by grants from a number of federal agencies, Research Incentive Awards from UT's Office of Research, and the UT/ORNL Science Alliance.

There are presently two graduate students working towards their Ph.D. degree in geology at IRIM. Kathy Ocker Stone, co-directed with Dr. H.Y. McSween, is studying Kr and Xe isotope ratios in microscopic mineral phases of meteorites to better understand their formation history, and Weiquan Dong, co-directed with Dr. L. A. McKay, is measuring the 85Kr concentration in groundwater to better understand the flow, recharge and potential for contaminant incursion in a major regional aquifer system.

The many instruments in our laboratory, which include four mass spectrometers, two multi-wavelength laser systems, water and gas processing systems, and lots of vacuum and electronic systems, is an invaluable resource for picking up practical laboratory research experience by both undergraduate and graduate students. As IRIM is still being developed, (and most likely will continue to be, in the foreseeable future) work that needs to be done not only includes knowing how to operate the equipment, but students also get intimately involved in the design and construction of new systems. Since its beginning, more than a dozen undergraduate and graduate students have done research and worked at IRIM.

Funded External Competitive Awards Since 1994

-A Novel Approach for Understanding the Recharge Mechanisms to the Memphis Aquifer in Shelby County, Tennessee, 4/1/00 - 3/31/03, American Water Works Association Research Foundation (subcontract through the University of Memphis.)

-Field-Testing of 85Kr as an Emerging Tool for Age-Dating Groundwater, I&II, 9/1/97 - 8/31/00, TN Water Resources Research Center, Water Resources Research Institute Program, U.S. Geological Survey.

-Stardust Active Volatiles Collector, 9/15/96 - 4/30/98, Jet Propulsion Laboratory (subcontract through Washington University, St. Louis).

-Krypton and Xenon Isotope Measurements from Single Micron-Sized Refractory Extraterrestrial Grains Using Laser-Based Resonance Ionization. 9/1/95 - 8/31/00, Innovative Research Program, OSS, NASA.

-Development of Laser-Based Resonance Ionization Techniques for 81Kr and 85Kr Measurements in the Geosciences, II. 12/1/94 - 11/30/99, Office of Basic Energy Sciences, U.S. Department of Energy.

-Development of Laser-Based Resonance Ionization Techniques for 81Kr and 85Kr Measurements in the Geosciences. 9/1/94 - 8/31/00, Division of Earth Sciences, Directorate for Geosciences, NSF.

Selected Publications and Presentations

K. D. Ocker, N. Thonnard and C. F. Joyner, "Versatile Sample Viewing System with Large Magnification Range," Rev. Sci. Instrum., in press, 1999.

K. Ocker and N. Thonnard, "The Path to Krypton and Xenon Isotope Measurements from Few-Micron Sized Samples; II. Pulsed UV Laser Microprobing." Lun. Planet. Sci. 30, Abstract #1622, LPI, Houston (CD-ROM), 1999.

C.M. Hohenberg, N. Thonnard, K. Kehm, A.P. Meshik, A. Berryhill and A. Glenn, "Active Capture of Volatiles: Implications for Planetary and Atmospheric Xenon," Meteorit. Planet. Sci. 33, A69, 1998.

N. Thonnard, L.D. McKay, D.H. Cumbie and C.F. Joyner, "Status of Laser-Based Krypton-85 Analysis Development for Dating of Young Groundwater," GSA Abstracts with Prog., 29, No. 6, A-78, 1997.

N. Thonnard and L.D. McKay, "Emerging New Ultra-Sensitive Analytical Techniques using Resonance Ionization: Applications in Groundwater Dating and Other Trace Analyses," ATV 1997 - Committee on Groundwater Pollution, Danish Academy of Technical Sciences, 135-149, April 23, 1997.

K. Ocker and N. Thonnard, "The Path to Krypton and Xenon Isotope Measurements from Few-Micron Sized Samples; I. A Low-Blank Gas Extraction System," Lun. Planet. Sci. 28, 1037, 1997.

N. Thonnard, "Resonance Ionization of Heavy Noble Gases: The Potential of Krypton and Xenon Measurements from Single Presolar Grains," Meteoritics 30, 588, 1995.

N. Thonnard and B.L. Lehmann, "The Institute for Rare Isotope Measurements: An Inter-Disciplinary Facility for RIS-Based Applications," AIP Conf. Proc., 329, 335, 1995.

M.G. Payne, L. Deng, and N. Thonnard, "Applications of Resonance Ionization Mass Spectrometry," Rev. Sci. Instrum., 65, 2433, 1994.

N. Thonnard, "Rare Noble Gas Isotope Measurements Using Laser-Based Resonance Ionization," US. Geo. Surv. Circ. 1107, 322, 1994.

N. Thonnard, M.C. Wright, W.A. Davis, and R.D. Willis, "The Second-Generation RIS-TOF Noble Gas Detector: Detection Limits Below 100 Atoms in Less Than 5 Minutes," Inst. Phys. Conf. Series 128, 27, 1992.

B.E. Lehmann, H.H. Loosli, D. Rauber, N. Thonnard, and R.D. Willis, "Kr and Kr in groundwater, Milk River Aquifer, Alberta, Canada," Applied Geochemistry 6, 419, 1991.

R. D. Willis, N. Thonnard, W. A. Davis, M.C. Wright, C.F. Joyner, and H. Craig, "Methodology for Krypton 81 Dating of Polar Ice and Groundwater in the Range of 50,000 to One Million Years," EOS 71, 1829, 1990.

N. Thonnard, J.E. Parks, R.D. Willis, L.J. Moore, and H.F. Arlinghaus, "Resonance Ionization of Neutral Atoms with Applications to Surface Science, Noble Gas Detection and Biomedical Analysis," Surf. Interf. Anal. 14, 751, 1989.