Blundell Thermal Physics · Problem 5.5

The Maxwell–Boltzmann distribution

Physics — Statistical Mechanics · doppler-broadening-formula

Problem

The width of a spectral line (FWHM) is often quoted as ΔλFWHM=7.16×10−7 λ0Tm,(5.27)\Delta\lambda^\mathrm{FWHM} = 7.16 \times 10^{-7}\, \lambda_0 \sqrt{\frac{T}{m}},\tag{5.27} where TT is the temperature in kelvin, λ0\lambda_0 is the wavelength at the centre of the spectral line in the rest frame and mm is the atomic mass of the gas measured in atomic mass units (i.e., multiples of the mass of a proton). Does this formula make sense?

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