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How does source temperature affect the energy of recoil-free gamma rays?
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Mössbauer effect
Figure 1: Spectrometer utilizing Mössbauer effect concept Effect is usually observed by measuring transmission of gamma rays from radioactive source through absorber containing resonant isotope.
In the context of the Mössbauer effect, the energy of a recoil-free gamma ray decreases as the source temperature increases.1
This phenomenon, known as the thermal red-shift, can be interpreted in two primary ways:
- Relativistic Doppler Effect: It can be viewed as a second-order Doppler effect resulting from the mean square thermal velocity of the atoms within the solid lattice.1
- Time Dilation: It can be interpreted as a direct demonstration of relativistic time dilation, where the moving atom acts as a clock that appears to slow down when viewed by a stationary observer.1
This thermal red-shift is significant in physics because it provides a direct experimental measurement of the mean square thermal velocity of atoms in a solid.1