ABSOLUTE MEASUREMENTS OF TOTAL CROSS SECTIONS FOR THE SCATTERING OF LOW-ENERGY ELECTRONS BY ATOMIC AND MOLECULAR OXYGEN.
NEW YORK UNIV N Y DEPT OF PHYSICS
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The atom beam recoil technique was used to measure absolute total cross sections for the scattering of electrons by atomic and molecular oxygen at 22 energies between 0.5 and 11.3 eV, with additional data obtained up to 100 eV. In this method, a modulated electron beam cross-fires an atom beam, whose attenuation at the modulation frequency is observed. The angular resolution in the electron polar scattering angle ranges from about 15.6 degrees at 1 eV to 9.6 degrees at 12 eV, for 0, and from about 18.5 degrees at 1 eV to 11.4 degrees at 12 eV, for 02. Our absolute values for 02 between 0.5 and 11.3 eV are between 10 and 20 higher than those of Bruche, while the shape of the curve agrees well. The atomic cross sections vary from about 5.3 sq. A at 0.5 eV to 8.3 sq. A at 11.3 eV, with an estimated error of 20 except for the 0.5 eV point which has an error of 30. These results are in excellent agreement with semi-empirical calculations of Cooper and Martin and Robinson and Geltman, as well as with the polarized orbitals calculation of Temkin. Author
- Atomic and Molecular Physics and Spectroscopy
- Nuclear Physics and Elementary Particle Physics