Collinear Fast-Beam Laser Spectroscopy

摘要: The progress in atomic and molecular spectroscopy has gone hand with improvements of the resolution. Before tunable narrow-band lasers led to invention Doppler-free techniques, spectral lines from cooled hollow-cathode discharges(1) had typical widths larger than 300 MHz, high resolution was achieved only rf spectroscopy, e.g., within hyperfine structure multiplets, by classical techniques like beam magnetic resonance,(2) optical pumρing,(3) or double resonance.(4) While Doppler broadening $$\delta {v_D} = {v_0}{\left( {{{8kT{\rm{ }}\ln {\rm{ 2}}} \over {m{c^2}}}} \right)^{1/2}}$$ (1) is negligible for resonance frequencies v 0 regime, narrowing resonances cooling low temperatures, T, obvious limits. On other hand, Eq. (1) holds an isotropic thermal velocity distribution, a narrow width requires reduction spread components along direction observation. It is well known ion optics that this can be electrostatic acceleration.