水汽分子碰撞加宽的理论研究

THE THEORETIC STUDIES OF COLLISION BROADENING OF WATER VAPOR ABSORPTION LINES

本文利用考虑短程强相互作用势、电四极矩_(H_2O)—电四极矩_(N_2)和电偶极矩_(H_2O)—电四极矩_(N_2)—相互作用的QFT理论(以下简称为QFT~*理论),计算了水汽分子纯转动带和_(v_2)振动带谱线的碰撞加宽线宽,以及v_(_2)振动带谱线线宽的温度依赖关系。结果表明:①利用QFT~*方法的计算值比Gamache等人的理论计算值更接近于实验值。③在计算水汽分子吸收谱线的氮分子碰撞加宽时,短程强相互作用势的影响是十分重要的,而电四极矩_(H_2O)—电四极矩_(N_2)相互作用的影响在任何情况下都是不大的,其贡献仅为1%左右。②压力加宽线宽的温度依赖关系是十分复杂的,字不仅与J有关,而且还与K_α有关。

The N2-broaden halfwidths of the pure rotation and v2 band of water vapor have been calculated by using QFT theory, which involve the three interrmolecular interactions: short range, dipole-quadrupole, and quadrupole-quadrupole (denoted as QFT'). The results show that; (1) our calculated values are closer to experimental results than the calculated values by Gamache and Davies; (2) in calculating N2 broadened halfwidths of wator vapor the contribution of short range interaction is important, whilet he nfluence of quadrupole-quadrupole interaction is negligible(about 1%); (3)the temper-ature dependence of collision halfwidths is complicated, depending ion both J and Kα.