2p-B-7 セシウム高励起原子の共鳴衝突 (self broadening) 効果

光 山本, 哲巨 大見

Birger Stahlberg, Markus Lindberg, Peter Jungner

The authors have investigated the zero-field level crossing lineshape in resonance absorption. A single-mode HeNe laser beam at 633 nm is applied to an external neon-gas absorption cell in a longitudinal magnetic field. They compare the measured lineshapes with theoretical predictions. Two superposed nonlinear Lorentzian-shaped resonances, known as the population effect of the 2p 4 -3s 2 transition and the Zeeman coherence effect of the lower 2p 4 level, appear on the background caused by the inhomogeneous broadening. Taking into account the background and the power broadening the authors obtain the linewidths at zero pressure gamma (2p 4 ,3s 2 )=(7.7+or-2.1) MHz and gamma (2p 4 )=(8.4+or-1.2) MHz. For the neon pressure broadening the authors get for pressures below 200 Pa (1.5 Torr) d gamma (2p 4 ,3s 2 )/dp=0.20+or-0.02 MHz Pa -1 and d(2p 4 )/dp=0.040+or-0.007 MHz Pa -1 . Their values are in acceptable agreement with the values obtained with other spectroscopic methods.

Yifan Shen

The dencity of sodium was determined from measurement of optical absorption of the resonance line. Sodium vapour, in the dencity 3×10~(11) to 1.2×10~(12)cm~(-3), was excited by a cw dye laser, tuned 70 GHz from D_2 resonance line. We recorded signal intensities, consisting of The Rayleigh component at the laser frequency and the two fluorescence components (direct and sensitized) at the atomic resonance-line frequencies. D_2 line self-broadening rate coefficient [k_(br,2)=5.44×10~(-7)cm~3/s(±15%)] was yielded. Combined with the effective radiative decay rates in the presence of radiation trapping, we measured excitation-transfer rates in different dencities, for the excitation transfer process Na(3P_(3/2))+Na(3S) Na (3P_(1/2))+Na(3S). The fine-structure collisional-mining cross section [σ_(21)(3P_(3/2)→3P_(1/2))=19.9nm~2(±29%)3 at T 184℃ was obtained. Our results were compared to other experiments and to theory.

祐輔 加藤

征靖 石川

C. Gerald Carrington, Alan Corney

Investigates the levels of the 2p 5 3p configuration of neon by studying the polarization of the light emitted by a dc neon discharge. The pressure broadening of the Hanle signals was studied and cross sections were obtained for the destruction of alignment for collisions with both helium and neon ground state atoms. The measurements have been made at 315 K and 85 K. The cross sections for the 2p 2 and 2p 6 levels (Paschen notation) change considerably with temperature, while the cross sections for other levels are almost independent of temperature.