Neutron lethargy (logarithmic energy decrement)

Input(s)

$E_{o}$: Initial Energy Level (eV)

E: Final Energy Level $(\mathrm{eV})$

Output(s)

$\mathrm{u}$: Neutron Lethargy (dimensionless)

Formula(s)

$$ u=\ln \left(\frac{E_{o}}{E}\right) $$

Reference(s)

Bassiouni, Z., 1994, Theory, Measurement, and Interpretation of Well Logs. SPE Textbook Series Vol. 4. Chapter 2, Page: 38.