It is shown that the decay in photon-echo amplitude with interval $T$ between pulses provides a new method for the determination of the small-angle dependence of the forward-elastic-scattering cross section $\ensuremath{\sigma}(V,\ensuremath{\theta})$, and that the experiment of Schmidt, Berman, and Brewer yields an analysis of $\ensuremath{\sigma}(V,\ensuremath{\theta})$ for C ${\mathrm{H}}_{3}$ F collisions. The result is in agreement with the $\frac{C}{{r}^{3}}$ interaction between molecules with permanent electric dipole moments.It is shown that the decay in photon-echo amplitude with interval $T$ between pulses provides a new method for the determination of the small-angle dependence of the forward-elastic-scattering cross section $\ensuremath{\sigma}(V,\ensuremath{\theta})$, and that the experiment of Schmidt, Berman, and Brewer yields an analysis of $\ensuremath{\sigma}(V,\ensuremath{\theta})$ for C${\mathrm{H}}_{3}$F collisions. The result is in agreement with the $\frac{C}{{r}^{3}}$ interaction between molecules with permanent electric dipole moments.

Physical Review ADec 1, 19748 citations

Generation and relaxation of photon echoes

Sven R. Hartmann

Jan 1, 19691 citation

Total Scattering Cross Section for Na on He Measured by Stimulated Photon Echoes

THOMAS W. MOSSBERG, Allen M. Flusberg, Ravinder Kachru +1 more

A technique which employs heretofore unappreciated aspects of the optical stimulated echo was developed and used to measure the total scattering cross section for $\mathrm{Na}(3{S}_{\frac{1}{2}})$ -He and $\mathrm{Na}(3{P}_{\frac{1}{2}})$ -He collisions. The repulsive-core-dominated $\mathrm{Na}(3{S}_{\frac{1}{2}})$ -He collision is found to be relatively soft. The cross section for degradation of the $3{S}_{\frac{1}{2}}\ensuremath{-}3{P}_{\frac{1}{2}}$ superposition, determined from photon-echo-decay measurements, is anomalous in that it is smaller than the total elastic-scattering cross section with Na in either state separately.A technique which employs heretofore unappreciated aspects of the optical stimulated echo was developed and used to measure the total scattering cross section for $\mathrm{Na}(3{S}_{\frac{1}{2}})$-He and $\mathrm{Na}(3{P}_{\frac{1}{2}})$-He collisions. The repulsive-core-dominated $\mathrm{Na}(3{S}_{\frac{1}{2}})$-He collision is found to be relatively soft. The cross section for degradation of the $3{S}_{\frac{1}{2}}\ensuremath{-}3{P}_{\frac{1}{2}}$ superposition, determined from photon-echo-decay measurements, is anomalous in that it is smaller than the total elastic-scattering cross section with Na in either state separately.

Physical Review LettersJun 18, 1979108 citations

Status of cross section data for photon scattering by atoms

Lynn D. Kissel, Richard H. Pratt

Jan 1, 19873 citations

Measurement of a Total Atomic-Radiator-Perturber Scattering Cross Section

Ravinder Kachru, T. J. Chen, Sven R. Hartmann +2 more

From work on the $2S\ensuremath{-}2{P}_{\frac{1}{2}}$ transition of atomic $^{7}\mathrm{Li}$ , perturbed by noble gases, and use of the photon-echo technique, the first measurement of a "total" atomic-radiator-perturber scattering cross section is reported. The phase-changing, inelastic, and velocity-changing aspects of collisions contribute to this cross section, which is significantly larger than the corresponding pressure-broadening cross section. Typical velocity changes are found to be roughly one percent of the mean thermal speed.From work on the $2S\ensuremath{-}2{P}_{\frac{1}{2}}$ transition of atomic $^{7}\mathrm{Li}$, perturbed by noble gases, and use of the photon-echo technique, the first measurement of a "total" atomic-radiator-perturber scattering cross section is reported. The phase-changing, inelastic, and velocity-changing aspects of collisions contribute to this cross section, which is significantly larger than the corresponding pressure-broadening cross section. Typical velocity changes are found to be roughly one percent of the mean thermal speed.

Physical Review LettersSep 28, 198130 citations

It is shown that the decay in photon-echo amplitude with interval

T

between pulses provides a new method for the determination of the small-angle dependence of the forward-elastic-scattering cross section $\ensuremath{\sigma}(V,\ensuremath{\theta})$, and that the experiment of Schmidt, Berman, and Brewer yields an analysis of $\ensuremath{\sigma}(V,\ensuremath{\theta})$ for C

{\mathrm{H}}_{3}

F collisions. The result is in agreement with the

\frac{C}{{r}^{3}}

interaction between molecules with permanent electric dipole moments.

A technique which employs heretofore unappreciated aspects of the optical stimulated echo was developed and used to measure the total scattering cross section for

\mathrm{Na}(3{S}_{\frac{1}{2}})

-He and

\mathrm{Na}(3{P}_{\frac{1}{2}})

-He collisions. The repulsive-core-dominated

\mathrm{Na}(3{S}_{\frac{1}{2}})

-He collision is found to be relatively soft. The cross section for degradation of the $3{S}_{\frac{1}{2}}\ensuremath{-}3{P}_{\frac{1}{2}}$ superposition, determined from photon-echo-decay measurements, is anomalous in that it is smaller than the total elastic-scattering cross section with Na in either state separately.

From work on the $2S\ensuremath{-}2{P}_{\frac{1}{2}}$ transition of atomic

^{7}\mathrm{Li}

, perturbed by noble gases, and use of the photon-echo technique, the first measurement of a "total" atomic-radiator-perturber scattering cross section is reported. The phase-changing, inelastic, and velocity-changing aspects of collisions contribute to this cross section, which is significantly larger than the corresponding pressure-broadening cross section. Typical velocity changes are found to be roughly one percent of the mean thermal speed.