Problem Solutions For Introductory Nuclear Physics By Kenneth S. Krane
The mass defect $\Delta M_d$ of the deuteron is given by $\Delta M_d = M_p + M_n - M_d$, where $M_p$, $M_n$, and $M_d$ are the masses of the proton, neutron, and deuteron, respectively.
| Problem | Common Mistake | Solution Tip | | :--- | :--- | :--- | | 2.3 – Rutherford scattering impact parameter | Confusing ( \theta ) (scattering angle) with ( \phi ) (azimuthal). | Draw the geometry. ( b = \frac12 \fracZ_1 Z_2 e^2E_\textlab \cot(\theta/2) ). | | 4.8 – Nuclear parity from pion capture | Forgetting that parity is multiplicative, and that the pion is pseudoscalar. | Write ( \pi_i = \pi_\pi \cdot \pi_\texttarget \cdot (-1)^L ). | | 9.3 – Gamma transition multipolarity | Using electric dipole (E1) selection rules for a transition between same-parity states. | ( \Delta \pi = \textno ) for E1? No — E1 requires parity change. | | 13.12 – Reaction threshold energy | Using ( E_\textth = -Q ) for non-relativistic case but forgetting the projectile-target mass factor. | Correct: ( E_\textth = -Q \fracm_\textprojectile + m_\texttargetm_\texttarget ). | The mass defect $\Delta M_d$ of the deuteron
Students often mistake having the solution for understanding the solution. Common negative patterns include: Problem 8
Let’s walk through the mindset for a typical problem from Chapter 8 (Alpha Decay): A complete solution would show the integral evaluation
Problem 8.9: Compute the half-life of (^212)Po for alpha decay to (^208)Pb, given that the alpha kinetic energy is 8.95 MeV. Use the WKB barrier penetration method, assuming a nuclear radius R = 1.2 A^1/3 fm and a Coulomb barrier. The reduced mass correction is important.
A complete solution would show the integral evaluation (using the substitution r = b cos²θ or the standard Gamow formula), then plug numbers to get t_1/2 ≈ 3×10⁻⁷ s. The measured half-life of (^212)Po is 3.0×10⁻⁷ s – excellent agreement.
Notice: No solution manual is needed if you can reconstruct this logic. The manual just confirms your steps.

