JMSSJ On-line

JMSSJ On-line, Vol. 49 (2001) No. 4, pp. 144-149

Peak Shape and Kinetic Energy Release in Charge Inversion Mass Spectrometry		>> Full Text PDF >> References
*Shigeo HAYAKAWA^a), Masayoshi MORI^a), Nobuaki WATANABE^a), Keizo FUJII^a), Kazuo ARAKAWA^b), and Norio MORISHITA^b)** ^a) College of Integrated Arts and Sciences, Osaka Prefecture University (1-1, Gakuencho, Sakai, Osaka 599-8531, Japan)* ^b) Takasaki Radiation Chemistry Research Establishment, Japan Atomic Energy Research Institute (1233, Watanuki, Takasaki, Gunma 370-1292, Japan)

A trapezoidal peak shape of dissociative ions is observed in the charge inversion mass spectra. The relation between the kinetic energy release (KER) and the peak shape was simulated. Dissociation with a specific KER value having very narrow distribution for both ionic and neutral species affords the trapezoidal peak shape in a mass spectrum. The KER value was evaluated from the full width at half maximum (FWHM) of the trapezoidal peak associated with the CH₃O^- ions formed from CH₃OH⁺ ions in the charge inversion mass spectrum. The KER value showed the good agreement with that evaluated from the velocity distribution of H atom formed from the photo-dissociation of neutral methanol. This agreement demonstrated that the excited neutral methanol dissociated predominantly into the methoxy radical and the hydrogen atom, and that charge inversion mass spectrometry gave the dissociation of energy-selected neutral species.

Key words: Charge inversion mass spectrometry, Kinetic energy release, Peak shape, Internal energy distribution, Dissociation of neutral species

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