钠共振线的自增宽和3~2P_(3/2,1/2)能级间的碰撞转移率

SELF-BROADENING OF THE SODIUM RESONANCE LINE AND EXCITATION-TRANSFER RATES BETWEEN THE 3 ~2P_(3/2) AND 3 ~2P_(1/2) LEVELS

利用光吸收技术测量钠蒸汽密度。在3×101^(11)到1.2×10^(12)cm^(-3)的密度范围内,将激光调谐到钠D_2线紫(红)端约70GHz,记录激光频率的Rayleigh散射,直接(D_2线)荧光和敏化(D_1线)荧光的强度。获得D_2线共振自增宽率系数k_(br,2)=5.44×10^(-7)cm^3/S±15%。给出了不同密度下Na(3P_(3/2))+Na(3S)Na(3P_(1/2))+Na(3S)的碰撞转移率。得到了在T≈184℃时碰撞转移截面σ_(21)=1.99nm±29%。并与其他的实验结果和理论作了比较。

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.