Field ionization process of Eu 4f<sup>7</sup>6s<em> n</em>p Rydberg states<xref ref-type="fn" rid="cpb150726fn1">*</xref>

Field ionization process of Eu 4f⁷6s np Rydberg states*

Zhang Jing^a),^b), Shen Li^a),^b), Dai Chang-Jian^a),^b)

The EFI spectra of the Eu 4f⁷6s(⁹S) n p Rydberg series at F = 2 kV·cm⁻¹. (a) An overview, and (b) the close-up. The dot line in panel (a) denotes the position of the first ionization limit.