High-resolution experimental and theoretical study of singly and doubly excited resonances in ground-state photoionization of neon

Abstract

An experimental and theoretical study of ground-state photoionization of neon is presented in the photon energy range between 44 and 53 eV. This portion of the spectrum is characterized by a singly excited Rydberg series 2s2p 6 np, and by overlapping doubly excited Rydberg series 2s 2 2p 4 3snp and 2s 2 2p 4 3pnl (lϭs,d).With the use of synchrotron radiation of Х3 meV spectral resolution, numerous hitherto unobserved resonances were resolved, including some which exhibit relativistic effects. To identify resonances observed here and in earlier works, we employed numerical calculations, which combine the eigenchannel R-matrix method, multichannel quantum defect theory, and the recoupling frame transformation. These nearly ab initio methods account for most of the observed features in the spectrum, including a class of spin-induced relativistic effects.

2s-Excitation and Photoionization of Neon Clusters

“…This question is related to the process that gives rise to the resonance that are also changed in excitation energy, shape, and width compared to the atomic features [36,39]. A suitable explanation comes from recent work [18], in which photoelectron spectra of neon clusters were discussed along with the Intramolecular Coulombic Decay (ICD).…”

“…The Ne 15 [36][37][38][39] were investigated. The resonant features that are superimposed to the 2p continuum can be described by the Rydberg formula [40]:…”

A facility for the analysis of the electronic structures of solids and their surfaces by synchrotron radiation photoelectron spectroscopy

“…Besides the offset σ 0 and amplitude σ F , it is characterised by the resonant energy ϵ R , the resonance width ∆ F , and the Fano asymmetry parameter q. These three parameters can be found in vast literature available on the subject (He 16,21 and Ne 18 ). For the purpose of fitting, we used tabulated values for ∆ F and q of the Fano resonances.…”

“…20 In the case of He spectra the 2, 1 3 resonance from the 1 P 0 series is used due to the extremely small natural linewidth about 0.1 meV. 21 In case of Ne we chose lines 12s − 14d, where each has an internal width below 10 µeV.…”

Laser-plasma extreme ultraviolet and soft X-ray sources based on a double stream gas puff target: interaction of the radiation pulses with matter

“…In case of plasmas created by FLASH laser pulses such mechanism is not possible. Energy of the 2s2p 6 excited state in respect to the ground state 2s 2 2p 6 is 48.475 eV while energy of a single photon in the FLASH laser beam is 38.7 eV [59]. In this case a one step process would require at least two−photon ionization.…”