Abstract：The fluorescence spectrum of cesium vapor was studied in a cell irradiated with the light of 852.3 nm resonance line from a single mode laser diode. From the intensities and spectra of the Cs and Cs2 fluorescence we identified several collisional and radiative processes in the excited cesium atom-dimer system. The atomic lines of the highly excited states were the result of collisional energy transfer from Cs(6P3/2)+Cs(6P3/2)to Cs(6D，8S) atoms. The Cs2(B 1∏u) band formed in Cs(6P)+Cs2(X 1Σ+g) collisions. The fine-structure mixing in 6 2P atoms was studied through excitation transfer，energy-pooling collision, and collisional excitation transfer between Cs2 and Cs. The authors estimated the value of rate coefficient for the collisional energy transfer from 6P3/2 to 6P1/2 to be(5.2±2.1)×10-11 cm3·s-1. For the excitation transfer process Cs2(B 1∏u)+ Cs(6S)→Cs2(X 1Σ+g)+Cs(6P1/2)，a rate coefficient of(1.0±0.4)×10-9 cm3·s-1 was yielded.
[1] Lam L K, Fujimoto J, Gallagher A C. J. Chem. Phys., 1978, 68(8): 3553. [2] Jabbour Z J，Namiotka R K ，Huennekens J. Phys. Rev.，1996, A54(2): 1372. [3] Keramati B，Masters M，Huennekens J. Phys. Rev.，1988, A38(9): 4518. [4] Huennekens J，Wu Z，Walker T G. Phys. Rev.，1985, A31(1): 196. [5] Wu Z，Huennekens J. J. Chem. Phys.，1984, 81(10): 4334. [6] Czajkowski M，Krause L. Can，J. Phys.，1965, 43: 1259.
