Electronic excitation ofN2by positron impact

Excitation of molecular vibrations by positron impact.

Absolute cross sections for the vibrational excitation of CO, CO2, and H2 by positron impact are presented for incident positron energies from 0.5 eV to several electron volts. The measurements use a novel technique that exploits the adiabatic motion of a positron beam in a strong magnetic field. This work is the first systematic experimental study of vibrational excitation by positron impact, ...

Positron-impact ionization, positronium formation, and electronic excitation cross sections for diatomic molecules

Absolute measurements are presented for the positron-impact cross sections for positronium formation, direct ionization, and total ionization of the diatomic molecules N2, CO, and O2, in the range of energies from threshold to 90 eV. Cross sections for the electronic excitation of the a 1 and a 1 state in N2 and the A 1 state in CO near threshold are also presented. The experiment uses a cold, ...

Excitation of electronic states of Ar, H(2), and N(2) by positron impact.

We have measured the first state-resolved, absolute cross sections for positron excitation of electronic states of an atom or molecule using a high resolution (Delta E approximately 25 meV FWHM) beam of positrons from a Penning-Malmberg trap. We present cross sections for the excitation of the low-lying levels of Ar, H(2), and N(2) for incident positron energies between threshold and 30 eV. For...

Electronic excitation of H2O by low-energy electron impact.

Excitation of electronic states in tetrahydrofuran by electron impact.

We report on differential and integral cross section measurements for the electron impact excitation of the three lowest lying Rydberg bands of electronic states in tetrahydrofuran. The energy range of the present experiments was 15-50 eV with the angular range of the differential cross section measurements being 15°-90°. The important effects of the long-range target dipole moment and the targ...