Two-dimensional Penning ionization electron spectroscopy of CH3I and CH2I2 by He*(23S) metastable atoms

Naoki Kishimoto, Andriy Borodin, Takuya Horio, Masakazu Yamazaki, Koichi Ohno

Research output: Contribution to journalConference article

Abstract

Penning ionization of iodomethane (CH3I) and diiodomethane (CH2I2) upon collision with metastable He*(2 3S) atoms was studied by collision-energy/electron-energy resolved two-dimensional Penning ionization electron spectroscopy (2D-PIES) over a wide range of collision energies (20 - 350 meV). Collision energy dependence of partial ionization cross sections (CEDPICS) indicates that the interaction with He*(23S) atoms around the valence molecular orbitals is attractive at low collision energies except for the only σCH molecular orbital region of iodomethane which has a repulsive character in the normal collision energy range (70 - 350 meV). Large bands at lower electron energies (3.7 - 5.5 eV) in PIES spectra were ascribed to autoionization from a transient ion-pair. The related entrance ionization channel has an attractive character. The excitation transfer, which is responsible for the I** autoionization, takes place in regions close to carbon atoms and is repulsive towards He*(23S) in the normal collision energy range. The superexcited complex of (He-CH2I2)** autoionizes via the excitation transfer occurring close to the σCI regions of the targets.

Original languageEnglish
Article number012014
JournalJournal of Physics: Conference Series
Volume235
Issue number1
DOIs
Publication statusPublished - Jan 1 2010
Externally publishedYes
EventInternational Workshop on Electronic Spectroscopy for Gas-phase Molecules and Solid Surfaces, IWES2009 - Matsushima, Japan
Duration: Oct 12 2009Oct 15 2009

Fingerprint

metastable atoms
electron spectroscopy
ionization
collisions
autoionization
energy
molecular orbitals
electron energy
atoms
ionization cross sections
entrances
excitation
methylidyne
valence
carbon

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Cite this

Two-dimensional Penning ionization electron spectroscopy of CH3I and CH2I2 by He*(23S) metastable atoms. / Kishimoto, Naoki; Borodin, Andriy; Horio, Takuya; Yamazaki, Masakazu; Ohno, Koichi.

In: Journal of Physics: Conference Series, Vol. 235, No. 1, 012014, 01.01.2010.

Research output: Contribution to journalConference article

Kishimoto, Naoki ; Borodin, Andriy ; Horio, Takuya ; Yamazaki, Masakazu ; Ohno, Koichi. / Two-dimensional Penning ionization electron spectroscopy of CH3I and CH2I2 by He*(23S) metastable atoms. In: Journal of Physics: Conference Series. 2010 ; Vol. 235, No. 1.
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