YAD-008 · Radioactivity Sample material

The Mössbauer effect

Recoil-free emission and resonant absorption of gamma rays (the Mössbauer effect), its physical basis, Mössbauer spectra (isomer shift, quadrupole and magnetic splitting), applications and the possibilities of artificially accelerating nuclear decay.

Estimated time: 3 h 4 activities

Learning objective

Understand why resonant absorption is not seen with free nuclei and how it is restored in a crystal.
Learn to work with the recoil-free fraction, natural line width and Doppler velocity scale.
Know the physical meaning of the shifts and splittings in a Mössbauer spectrum.
Analyse applications of Mössbauer spectroscopy and ways of artificially changing nuclear decay rates.

Expected outcomes

Can calculate the recoil energy E_R and the level width Γ and compare them.
Can convert a Doppler velocity into an energy shift and back.
Can explain the number of lines in the ⁵⁷Fe spectrum and the meaning of the isomer shift.
Can explain the Pound–Rebka experiment and examples of artificially accelerated decay (bound-state beta decay, isomer depletion).

Interactive modelThe Mössbauer effect: resonant absorption

Activities

Lecture
Lecture · 1 h 20 min · required
Selection rules. Resonant scattering of gamma rays. The Mössbauer effect
Practice · 1 h 20 min · required
The Mössbauer effect and its applications
Self-study · 6 h 40 min · optional
Final test
Test · 20 min · required · pass ≥ 70%

Completion conditions

  • Lecture
  • Selection rules. Resonant scattering of gamma rays. The Mössbauer effect
  • Final test — at least 70%