Formation of hot hydrogen atoms from superexcited states of acetylene

Yoshiaki Kumagai; Takeshi Odagiri; Motoyoshi Nakano; Isao H Suzuki; Kouichi Hosaka; Masashi Kitajima; Noriyuki Kouchi

doi:10.1063/1.5058101

Formation of hot hydrogen atoms from superexcited states of acetylene

J Chem Phys. 2018 Dec 28;149(24):244302. doi: 10.1063/1.5058101.

Authors

Yoshiaki Kumagai¹, Takeshi Odagiri², Motoyoshi Nakano¹, Isao H Suzuki², Kouichi Hosaka¹, Masashi Kitajima¹, Noriyuki Kouchi¹

Affiliations

¹ Department of Chemistry, Tokyo Institute of Technology, Tokyo 152-8551, Japan.
² Department of Materials and Life Sciences, Sophia University, Tokyo 102-8554, Japan.

PMID: 30599704
DOI: 10.1063/1.5058101

Abstract

The cross sections for the formation of the H(2p) and H(2s) atoms, σ _2p and σ _2s , respectively, in photoexcitation of C₂H₂ were obtained in an absolute scale for studying formation and decay of superexcited states in the extreme ultraviolet range. Several superexcited states of C₂H₂ including multiply excited states were found in the curve of the σ _2p cross sections as a function of the incident photon energy. The same states seem to contribute to the variation in the σ _2s cross sections as well, which can be ascribed to the non-adiabatic transitions between the 2p and 2s channels. The Σ/Π symmetry-resolved cross sections for the H(2s) atom formation, $σ_{2 s}^{Σ}$ and $σ_{2 s}^{Π}$ , were also obtained on an absolute scale. The coupling between the ${}^{1}Σ_{u}^{+}$ and ¹Π _u states was found to be small.