A new method for measuring cross sections for the scattering of electrons by laser-excited atoms is described. It is a generalization of the atomic-beam recoil technique, taking advantage of the recoil of atoms during resonant photon interactions to spatially separate excited from nonexcited atoms. A preliminary value for the total cross section for the scattering of electrons by the $3^{2}P_{\frac{3}{2}}({m}_{F}=3)$ state of sodium at 4.4 eV is presented.A new method for measuring cross sections for the scattering of electrons by laser-excited atoms is described. It is a generalization of the atomic-beam recoil technique, taking advantage of the recoil of atoms during resonant photon interactions to spatially separate excited from nonexcited atoms. A preliminary value for the total cross section for the scattering of electrons by the $3^{2}P_{\frac{3}{2}}({m}_{F}=3)$ state of sodium at 4.4 eV is presented.

Physical Review LettersJan 3, 197737 citations

Elastic electron scattering by laser-excited138Ba( ... 6s6p1P1) atoms

Sandor Trajmar, I. Kanik, M. A. Khakoo +4 more

The results of a joint experimental and theoretical study concerning elastic electron scattering by laser-excited 138 Ba( ... 6s6p 1 P 1 ) atoms are described. These studies demonstrate several important aspects of elastic electron collisions with coherently excited atoms, and are the first such studies. From the measurements, collision and coherence parameters, as well as cross sections associated with an atomic ensemble prepared with an arbitrary in-plane laser geometry and linear polarization (with respect to the collision frame), or equivalently with any magnetic sublevel superposition, have been obtained at 20 eV impact energy and at 10°, 15° and 20° scattering angles. The convergent close-coupling (CCC) method was used within the non-relativistic LS -coupling framework to calculate the magnetic sublevel scattering amplitudes. From these amplitudes all the parameters and cross sections at 20 eV impact energy were extracted in the full angular range in 1° steps. The experimental and theoretical results were found to be in good agreement, indicating that the CCC method can be reliably applied to elastic scattering by 138 Ba( ... 6s6p 1 P 1 ) atoms, and possibly to other heavy elements when spin-orbit coupling effects are negligible. Small but significant asymmetry was observed in the cross sections for scattering to the left and to the right. It was also found that elastic electron scattering by the initially isotropic atomic ensemble resulted in the creation of significant alignment. As a byproduct of the present studies, elastic scattering cross sections for metastable 138 Ba atoms were also obtained.The results of a joint experimental and theoretical study concerning elastic electron scattering by laser-excited 138 Ba( ... 6s6p 1 P 1 ) atoms are described. These studies demonstrate several important aspects of elastic electron collisions with coherently excited atoms, and are the first such studies. From the measurements, collision and coherence parameters, as well as cross sections associated with an atomic ensemble prepared with an arbitrary in-plane laser geometry and linear polarization (with respect to the collision frame), or equivalently with any magnetic sublevel superposition, have been obtained at 20 eV impact energy and at 10°, 15° and 20° scattering angles. The convergent close-coupling (CCC) method was used within the non-relativistic LS -coupling framework to calculate the magnetic sublevel scattering amplitudes. From these amplitudes all the parameters and cross sections at 20 eV impact energy were extracted in the full angular range in 1° steps. The experimental and theoretical results were found to be in good agreement, indicating that the CCC method can be reliably applied to elastic scattering by 138 Ba( ... 6s6p 1 P 1 ) atoms, and possibly to other heavy elements when spin-orbit coupling effects are negligible. Small but significant asymmetry was observed in the cross sections for scattering to the left and to the right. It was also found that elastic electron scattering by the initially isotropic atomic ensemble resulted in the creation of significant alignment. As a byproduct of the present studies, elastic scattering cross sections for metastable 138 Ba atoms were also obtained.

Journal of Physics B Atomic Molecular and Optical PhysicsJan 1, 199912 citations

Cooperative Raman scattering by a concentrated system of atoms

V. I. Rupasov

Journal of Experimental and Theoretical PhysicsOct 1, 19880 citations

Total cross sections for electrons scattered by 32 P3/2 sodium atoms

Bernardo Jaduszliwer, GF Shen, J.-L. Cai +1 more

An electron and photon atomic-recoil technique has been used to measure absolute total cross sections for electrons scattered by ${3}^{2}$ ${P}_{3/2}$ sodium atoms in the 6--25-eV energy range, with the use of a new, high-resolution crossed-beam apparatus. A single-mode tunable ring dye laser is used to selectively excite the F=3 hyperfine level. Excited-state populations are determined by using the atomic recoil in resonant photon absorption. At 6 eV there is very good agreement with a previous measurement [B. Jaduszliwer, R. Dang, P. Weiss, and B. Bederson, Phys. Rev. A 21, 808 (1980)].An electron and photon atomic-recoil technique has been used to measure absolute total cross sections for electrons scattered by ${3}^{2}$${P}_{3/2}$ sodium atoms in the 6--25-eV energy range, with the use of a new, high-resolution crossed-beam apparatus. A single-mode tunable ring dye laser is used to selectively excite the F=3 hyperfine level. Excited-state populations are determined by using the atomic recoil in resonant photon absorption. At 6 eV there is very good agreement with a previous measurement [B. Jaduszliwer, R. Dang, P. Weiss, and B. Bederson, Phys. Rev. A 21, 808 (1980)].

Physical Review AFeb 1, 198522 citations

3^{2}P_{\frac{3}{2}}({m}_{F}=3)

state of sodium at 4.4 eV is presented.

An electron and photon atomic-recoil technique has been used to measure absolute total cross sections for electrons scattered by

{3}^{2}

{P}_{3/2}

sodium atoms in the 6--25-eV energy range, with the use of a new, high-resolution crossed-beam apparatus. A single-mode tunable ring dye laser is used to selectively excite the F=3 hyperfine level. Excited-state populations are determined by using the atomic recoil in resonant photon absorption. At 6 eV there is very good agreement with a previous measurement [B. Jaduszliwer, R. Dang, P. Weiss, and B. Bederson, Phys. Rev. A 21, 808 (1980)].