The small binding energy of the deuteron indicates that the maximum of U(r) lies only just inside the range R of the square well

The inside wave function u₁ = Asinkr is maximum at r ≈ R. Therefore

Substituting ℏc = 197.3MeV − fm, Mc² = 940MeV, R = 1.5fm and W = 2.2Mev, we find V₀ ≈ 47 MeV

The small binding energy of the deuteron indicates that the maximum of U(r) lies only just inside the range R of the square well potential.