Henry S. Valk
Ph.D., Washington University, 1957
Theoretical determination of the properties of few-atom and few nucleon systems
Professor Valk's recent research has centered on a theoretical determination of the properties of few-atom and few nucleon systems using the technique of hyperspherical-harmonic expansions. In this approach, the Schrodinger equation describing the system is converted into an infinite set of coupled second-order differential equations in a single radial variable, or a single integro-differential equation. The solution to such equations gives the wave function of the system from which the various static properties can be calculated.
This expansion procedure has been quite successful in reproducing the binding energies, form factors, and electric-dipole photo-absorption cross sections of light nuclei. It has also been reasonably useful in determining the binding energies of small noble gas clusters. Recent theoretical methods based on a consistent haldling of the two-body correlations give promise of directly extending these calculations to clusters containing tens to hundreds of constituents, systems that are the objects of increasing experimental interest. Research is currently underway on these extensions.
- H. S. Valk, J. S. Levinger, and Z. Felfli, "What Determines the Trimer Energy," Proc. Intnl. Sem. on Microscopic Methods in Few-Body Systems Theory, edited by A. M. Gorbatov, 2, 135 (1988).
- H. S. Valk and J. S. Levinger, "Hyperspherical Expansions for an Exactly Soluble Three-Body Model," 12th International Conference on Few- Body Problems in Physics, TRI-UMF Report 89-2, A2 (1989).
- H. S. Valk and J. S. Levinger, "Hyperspherical Harmonics Applied to an Exactly Solvable Three-Body Problem," Annals of Physics (New York) 199, 141 (1990).