Few Body Studies at the University of North Texas


When Duane Jaecks retired from UNL, the Few-Body apparatus was moved to the University of North Texas. The goal of these experiments is to develop an understanding of the few body problem by uniquely correlating the initial quantum state to the asymptotic final state parameters (final state momentum and energy) of each fragment of a dissociative system.  This is accomplished by measuring all of the parameters in coincidence (triple coincidence with three position-sensitive detectors).  In particular, we choose a system where all fragments are charged, thus maintaining a long range interaction as they move from the quantum to the continuum states.


Figure 1  Experimental Schematic


These experiments are being continued as a collaboration among Prof. Emeritus Duane Jaecks and three generations of his students Prof. Dennis Mueller (UNT), Dr. Lisa Wiese, and Dr. Brandon Jordon-Thaden.


Figure 2  Success in placing the 1000lb gorilla on it's pedestal             

Figure 3 Lisa tending to the Energy Analyzer


Figure 4  Connecting the center of mass to lab frame coordinates



Posters from previous presentation may be viewed by clicking on these links:

DAMOP 2003 and

Chaotic Systems


A simulation of the trajectories may be view at the following links:

Big epsilon, the case where the internal energy is shared equally;

Small epsilon, where two of the particles move off with relatively low relative velocities; and

Bound systems, which follows two of the particles forming a bound system with large angular momentum.

These simulations were produced by Dr. Jordon-Thaden, who numerically solved the equations of motion and tracked the resulting trajectories of the fragments.


For additional information, contact Dennis Mueller mueller@unt.edu

For more immediate and detailed information, view the PowerPoint dissertation defense presentation by Brandon Jordon-Thaden (this is a very large file ~15MB)


Brandon's dissertation (~7MB) is also available for online viewing