Measurement and theoretical evaluation of cross section for Na (4D) +Na (3S) →Na (4F) +Na (3S)

Measurement and theoretical evaluation of cross section for Na (4D) +Na (3S) →Na (4F) +Na (3S) 1 first-author 1 1 1 Department of Physics, Xinjiang University, Urumqi 830046 Department of Physics, Xinjiang University, Urumqi 830046 Cross section σ 4D→4F was measured for the collision transfer process of Na (4D) + Na (3S) → Na (4F) + Na (3S) . The 4D state is excited by two-photon absorption using a tunable dye laser. Since the 4F→3D fluorescence can not be detected directly with the apparatus used the cascade 3D→3P fluorescence is monitored instead. Then the cross-section σ 4D→4F = (1.3 ± 0.3) ×10 -14 cm 2 is got from the relative intensity of the fluorescence. A theoretical evaluation of σ 4D → 4F is also given and compared with experimental results. Cascade fluorescence Cross section Landau-Zener approximation References Mallory T R , Kedzierski W , Atkinson J B et al . Phys Rev , 1988 ; A38 : 5917 Phys Rev Allegrini M , Gabbanini C , Moi L . Phys Rev , 1985 ; A32 : 2068 Phys Rev Wiese W L , Smith M W , Miles B M . Atomic transition probabilities, NSRDS-NB21 . U.S. GPO , Washington D C , 1969 Atomic transition probabilities, NSRDS-NB21 Davidson S A , Kelly J F , Gallagher A . Phys Rev , 1986 ; A33 : 3756 Phys Rev Nesmeyanov A N , Vapor pressure of the chemical elements . Amsterdam : Elsevier , 1963 Vapor pressure of the chemical elements Bransden B H . Atomic collsion theory . England : Durham , 1983 Atomic collsion theory Huennekens J , Gallagher A . Phys Rev , 1983 ; A27 : 1851 Phys Rev The Project Supported by National Natural Science Foundation of China 1997-03-20 1997-08-01 2021-02-05 1997 Nuclear Science and Techniques 3 8