YAD-005 · The atomic nucleus Sample material

Nuclear models

Why nuclear models are needed and how they are classified: the liquid-drop model and the Weizsäcker formula, the Fermi-gas model, the shell model and magic numbers, the unified (collective) model — rotational and vibrational states.

Estimated time: 3 h 3 activities

Learning objective

Understand why the nucleus has to be described with models.
Know the physical meaning of the terms of the Weizsäcker formula and use it in calculations.
Learn to estimate the Fermi energy and potential depth in the Fermi-gas model.
Explain ground-state spin and parity with the shell model and rotational spectra with the unified model.

Expected outcomes

Can calculate the binding energy and the stable isobar with the semi-empirical mass formula.
Can find the Fermi momentum and energy from the density of nuclear matter.
Can predict the ground-state I^π of odd-A nuclei from shell filling.
Can calculate rotational-band energies with E = ħ²I(I+1)/2𝓙.

Interactive modelThe liquid-drop model of the nucleus
Interactive modelThe nuclear shell model and magic numbers

Activities

Lecture
Lecture · 1 h 20 min · required
Nuclear models. The liquid-drop model. The Fermi-gas model. The shell model. The unified nuclear model
Practice · 1 h 20 min · required
Final test
Test · 20 min · required · pass ≥ 70%

Completion conditions

  • Lecture
  • Nuclear models. The liquid-drop model. The Fermi-gas model. The shell model. The unified nuclear model
  • Final test — at least 70%