Atoms in external fields are interesting systems because the electron trajectories can be chaotic or regular near the ionization threshold, depending on the external fields applied and the core potential of the atom. Experimentalists can excite electrons into states near the ionization threshold with lasers, so the atoms become testing grounds for the connection between classical mechanics and quantum mechanics in both theory and experiment.
I have been particularly interested in the effect of core scattering in alkali atoms on closed-orbit theory (see the comparison with the MIT quantum calculation below) and written computer codes which take this effect into account.
My thesis work with Dr. John B. Delos , College of William & Mary, and Dr. Jian-Min Mao , Hong Kong University of Science and Technology , applied closed-orbit theory to the photoabsorption spectrum of atoms in magnetic fields. We analyzed experiments done in Germany at the University of Bielefeld.
Later experiments were done in the Netherlands at the laser center of the Free University in Amsterdam. This was a prolific group under the guidance of Wim Hogervorst: Tony van der Veldt completed his thesis in 1993, Jereon Wals completed his thesis in 1996, Marcel Lankhuijzen in 1997, Kees Karremans and Annemieke Kips completed theirs in 1999. I worked most closely with Tony van der Veldt, had little contact with Jereon and Marcel, but I recently, 1998-1999, travelled to Amsterdam to work at FOM/Amolf, and did some more computations for Annemieke and Kees.
My semiclassical calculations were also compared to quantum calculations done by Michael Courtney in his thesis, 1994. Michael was part of the atomic physics group at the Massachusetts Institute of Technology . Here is an example calculation and experiment al spectrum showing core scattering effects in Lithium atoms in a magnetic field. In a case of a good idea being developed by two different research groups independently, similar work was done by Paul Dando and Tanya Monteiro at the University College in London, 1995.
In a completely different field, I worked briefly with Dr. Eugene Tracy , 1994-1995. studying the effects of random noise on deterministic maps. This research was associated with the plasma and nonlinear physics group at William and Mary.
Here is my vita and publication list. If you are interested in an annotated list of publications by members of the William and Mary atomic theory group on closed-orbit theory click here (under construction and needing a major update).
I left William and Mary to take a postdoctoral fellowship at Auburn University in the atomic/radiative physics group led by Dr. Michael Pindzola, 1995 -1999. This research was on electron impact ionization cross sections for the major impurity ions found in controlled fusion experiments. This was supported by the DOE Office of Fusion Energy. Some others involved in this research were Dr. Don Griffin, Rollins College, Dr. Nigel Badnell, University of Strathclyde, and Dr. Francis Robicheaux at Auburn University.
Most recently I finished a one year visiting assistant professor position at Centenary College in Louisiana and have been more involved in teaching than research. I live in Monroe, Louisiana.