7.1 Figure 1

 

Sketch of one possible trajectory of bremsstrahlung zeros based on known position of Ramsauer-Townsend minimum in elastic scattering (near E⁰). The filled circle in the first quadrant represents the position of the soft photon zero associated with the Ramsauer-Townsend minimum. The filled circle at the origin represents the zero present for all neutral atom potentials which do not support l=0 virtual bound states at threshold. The filled circles in the second quadrant represent the possible continuation of the bremsstrahlung zeros into the bound free transition quadrant.