Line Broadening and the Imprisonment of Resonance Radiation

M.J. Boxall, C.J. Chapman, Richard P. Wayne

Sergei I Yakovlenko

Rochelle Lai, Shilin Liu, Xingxiao Ma

P. J. Walsh

The transmission coefficient defined by Holstein for resonance radiation has been calculated when Doppler and collision broadening of the resonance line are present simultaneously. From this a simple formula is inferred for the imprisonment lifetime of the resonance radiation under this condition. The complication of the hyperfine structure is also taken into account and the results are found to give good agreement with experiments in mercury.

Abdul-Wahab Kadir Ali

Heinrich Gerhard Kuhn, Janet Maria Vaughan

Abstract By means of a direct recording Fabry-Perot interferometer, the contours of several singlet lines of helium were studied over a wide range of pressure and temperature. The source was a microwave discharge cooled with liquid nitrogen or liquid helium. Analysis of the tracings allowed the Doppler and Lorentz components to be separated quantitatively. A detailed study was carried out for the line λ 7281 Å (21P - 31S). By extrapolation of the Lorentz width to zero pressure the radiation width of the level 2 was determined and led to an ƒ-value 0·377 + 0·035 of the resonance line λ 584 Å (11S— 21P) The resonance broadening is found to be independent of the speed of the atoms, over a range of a factor five in the speed, in agreement with theories of optical collision by Weisskopf and others. The absolute value of the resonance broadening constant is compared with various theories. The strong line λ 6678 Å (21P -31D) showed self-absorption due to imprisonment of resonance radiation.