Finite Spherical Well and Deuterium Nucleus Attractive potential exists between proton and neutron (pic) step function potential Assume l=0 then S.E. for radial function is −͟ħ͟²͟ ⎛∂͟²͟ R + 2͟ ∂͟ R⎞V R = E R 2m ⎝∂r² r ∂r ⎠ K² ≡ (E͟_͟−͟_͟V͟)2m ⇒ ∂͟²͟ R + 2͟ ∂͟ R + K² R = E R ħ² ∂r² r ∂r R(r) = U(r)/r ⇒ ∂͟²͟ U = - K² R ∂r² For r