Isotope effect in dissociative electron attachment to acetylene

Journal Article · Wed Jul 15 04:00:00 EDT 2009 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.80.012706· OSTI ID:21313267

May, O; Fedor, J; Allan, M ^[1]

---

1. Department of Chemistry, University of Fribourg, Chemin du Musee 9, 1700 Fribourg (Switzerland)

Absolute partial cross sections for dissociative electron attachment to H-C{identical_to}C-H and D-C{identical_to}C-D have been measured using a time-of-flight ion spectrometer combined with a trochoidal electron monochromator. For C{sub 2}H{sub 2} the present data are in good agreement with the total cross sections measured previously in our laboratory using the total ion-collection method. The present measurements on deuterated acetylene revealed a pronounced isotope effect at the first dissociative electron attachment band at 3 eV, with the cross section for C{sub 2}D{sup -}/C{sub 2}D{sub 2} being 14.4 times smaller than that for C{sub 2}H{sup -}/C{sub 2}H{sub 2}. The dominant fragments at the second dissociative attachment band around 8 eV are the light fragments H{sup -} or D{sup -}. These bands exhibit weaker isotope effects, in agreement with their assignment to Feshbach resonances with narrow autodetachment widths.

• OSTI ID: 21313267
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 1 Vol. 80; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ACETYLENE
DEUTERIUM IONS
DISSOCIATION
ELECTRON ATTACHMENT
ELECTRON-MOLECULE COLLISIONS
ELECTRONS
EV RANGE
HYDROGEN IONS 1 MINUS
ISOTOPE EFFECTS
ISOTOPES
RESONANCE
SPECTRA
SPECTROMETERS
TIME-OF-FLIGHT METHOD
TOTAL CROSS SECTIONS