27/04/2018: S-Wave Phase Shift, Spherical Well
Algebraic Approach
Solve for δ:
Express in terms of dimensional less parameters where ka is y and S is x
1-D Plots
Plot the Phase Shift
Fix the discontinuity by plotting δ modulo-π:
Contour Plot
Make the Contour Plot, remembering to use a lot of PlotPoints to capture the more irregular artifacts: