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oai:uvadoc.uva.es:10324/842682026-04-22T19:00:52Zcom_10324_1157com_10324_931com_10324_894col_10324_1298

Xiong, Qing Nikiforov, Anton Yu González, Manuel Á Leys, Christophe Lu, Xin Pei 2026-04-22T12:24:42Z 2026-04-22T12:24:42Z 2013 Plasma Sources Science and Technology, 2013, vol. 22, n. 1, p. 015011 0963-0252 https://uvadoc.uva.es/handle/10324/84268 10.1088/0963-0252/22/1/015011 015011 1 Plasma Sources Science and Technology 22 1361-6595 The characteristics of plasma temperatures (gas temperature and electron excitation temperature) and electron density in a pulsed-dc excited atmospheric helium plasma jet are studied by relative and absolute optical emission spectroscopy (OES). High-resolution OES is performed for the helium and hydrogen lines for the determination of electron density through the Stark broadening mechanism. A superposition fitting method composed of two component profiles corresponding to two different electron densities is developed to fit the investigated lines. Electron densities of the orders of magnitude of 1021 and 1020 m−3 are characterized for the center and edge regions in the jet discharge when the applied voltage is higher than 13.0 kV. The atomic state distribution function (ASDF) of helium demonstrates that the discharge deviates from the Boltzmann–Saha equilibrium state, especially for the helium lower levels, which are significantly overpopulated. Local electron excitation temperatures T13 and Tspec corresponding to the lower and upper parts of the helium ASDF are defined and found to range from 1.2 eV to 1.4 eV and 0.2 eV to 0.3 eV, respectively. A comparative analysis shows that the Saha balance is valid in the discharge for helium atoms at high excited states. eng info:eu-repo/semantics/restrictedAccess IOP Publishing Characterization of an atmospheric helium plasma jet by relative and absolute optical emission spectroscopy info:eu-repo/semantics/article