Observation of a Four-Electron Auger Process in Near-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>K</mml:mi></mml:math>-Edge Photoionization of Singly Charged Carbon Ions

Müller, A.; Borovik, A.; Buhr, T.; Hellhund, J.; Holste, K.; Kilcoyne, A. L. D.; Klumpp, S.; Martins, M.; Ricz, S.; Viefhaus, Jens; Schippers, S.

doi:10.1103/physrevlett.114.013002

Cited by 71 publications

(67 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this paper, which is a follow-up of a previous Letter [3], details of the experiments are presented. In particular, the experimental data are compared to available theoretical results from different computational approaches.…”

Section: Discussionmentioning

confidence: 99%

Near-K-edge single, double, and triple photoionization ofC+ions

et al. 2018

Self Cite

View full text Add to dashboard Cite

Single, double, and triple ionization of the C + ion by a single photon have been investigated in the energy range 286 to 326 eV around the K-shell single-ionization threshold at an unprecedented level of detail. At energy resolutions as low as 12 meV, corresponding to a resolving power of 24 000, natural linewidths of the most prominent resonances could be determined. From the measurement of absolute cross sections, oscillator strengths, Einstein coefficients, multi-electron Auger decay rates and other transition parameters of the main K-shell excitation and decay processes are derived. The cross sections are compared to results of previous theoretical calculations. Mixed levels of agreement are found despite the relatively simple atomic structure of the C + ion with only 5 electrons. This paper is a follow-up of a previous Letter [Müller et al., Phys. Rev. Lett. 114, 013002 (2015)].

show abstract

Section: Discussionmentioning

confidence: 99%

Near-K-edge single, double, and triple photoionization ofC+ions

et al. 2018

Self Cite

View full text Add to dashboard Cite

show abstract

“…It appears that autoionization accompanied by double shake-up has to be taken into account for reproducing the major part of the experimental findings. Similar four-electron Auger processes have been discussed recently also for photoionization [23,24] and photorecombination [29] of positively charged atomic ions. K-shell photodetachment of negative ions continues to be a challenge for state-of-theart atomic theory.…”

mentioning

confidence: 87%

“…We found that the Auger processes under consideration are strongly influenced by shake-up transitions. Direct multiple Auger processes [23] resulting from higher-order many-electron interactions [24] must be expected to be much weaker than the shake-up of valence electrons. Here we neglect this non-sequential multiple autoionization and only include shake-up processes in our calculations.…”

mentioning

confidence: 99%

Prominent role of multielectron processes inK-shell double and triple photodetachment of oxygen anions

et al. 2016

Self Cite

View full text Add to dashboard Cite

The photon-ion merged-beams technique was used at a synchrotron light source for measuring absolute cross sections of double and triple photodetachment of O − ions. The experimental photon energy range of 524-543 eV comprised the threshold for K-shell ionization. Using resolving powers of up to 13000, the position, strength and width of the below-threshold 1s 2s 2 2p 6 2 S resonance as well as the positions of the 1s 2s 2 2p 5 3 P and 1s 2s 2 2p 5 1 P thresholds for K-shell ionization were determined with high-precision. In addition, systematically enlarged multi-configuration Dirac-Fock calculations have been performed for the resonant detachment cross sections. Results from these abinitio computations agree very well with the measurements for the widths and branching fractions for double and triple detachment, if double shake-up (and -down) of the valence electrons and the rearrangement of the electron density is taken into account. For the absolute cross sections, however, a previously found discrepancy between measurements and theory is confirmed. Negative atomic ions play an important role in lowtemperature plasmas such as the upper atmosphere or the interstellar medium [1] and also in technical applications. For example, in the context of antihydrogen production, it has been proposed to use an ensemble of laser-cooled anions as a coolant for antiprotons [2]. Negative ions are fundamentally different from neutral atoms or positive ions since the extra electron in a negative ion is not only bound by the long-range Coulomb interaction with the atomic nucleus but, more importantly, also by a short-range attractive force due to the polarization of the atomic core. The accurate theoretical description of these ions still challenges the state-of-the-art quantum computations although the numbers of their bound states are generally finite. The low-excitation levels of negative ions are readily accessible by laser spectroscopy (see, e.g., [3][4][5][6]). Therefore, this technique has been a prime source of experimental information about the mutual interactions among the valence electrons.A sensitive tool for studying the interactions between the valence and the core electrons is inner-shell ionization of negative ions [7,8]. Here, we apply the photon-ion merged-beams technique (see [9] for a recent overview) to determine the absolute cross sections for double and triple ionization (detachment) of oxygen anions in the photon energy range 524-543 eV. In this energy range, a K-shell vacancy may be produced either by direct ionization of an initial 1s electron or via the formation of a resonance state by exciting one 1s electron to a higher shell such as 2p. In either case, the K-vacancy decays subsequently by a cascade of radiative and nonradiative processes leading to a distribution of final charge states with O + and O 2+ as the most prominent charged reaction products. To test and better understand the theoretical prediction of such cascades, we performed extremely comprehensive quantum calculations for the formation...

show abstract

“…An overview of deep-inner-shell photoabsorption by atomic cations and anions has been provided recently by Müller (Müller 2015). Experimental data on K-shell photoionization and photoexcitation of positive ions with atomic numbers  Z 3 have been published for Li +  (Carroll & Kennedy 1977;Kiernan et al 1994;Mosnier et al 2000;Scully et al 2006), Be +  (Mehlmann & Esteva 1974), B + (Müller et al 2014), B 2+ (Müller et al 2010a), C + (Schlachter et al 2004;Müller et al 2015), C 2+ (Scully et al 2005), C 3+ (Müller et al 2009), N + (Gharaibeh et al 2011), N 2+ (Gharaibeh et al 2014) (Rudolph et al 2013;Steinbrügge et al 2015), Fe 24+ (Rudolph et al 2013), and Kr 34+ . K-shell photoionization experiments with neutral neon atoms have employed static gas targets, and a large body of papers has addressed specific features in the excitation and decay of K-shell vacancies in neon atoms.…”

Section: Introductionmentioning

confidence: 99%

Photoionization of Ne Atoms and Ne⁺ Ions Near the K Edge: PrecisionSpectroscopy and Absolute Cross-sections

Müller

Bernhardt

Borovik

et al. 2017

ApJ

114

View full text Add to dashboard Cite

Single, double, and triple photoionization of Ne + ions by single photons have been investigated at the synchrotron radiation source PETRA III in Hamburg, Germany. Absolute cross-sections were measured by employing the photon-ion merged-beams technique. Photon energies were between about 840 and 930 eV, covering the range from the lowest-energy resonances associated with the excitation of one single K-shell electron up to double excitations involving one K-and one L-shell electron, well beyond the K-shell ionization threshold. Also, photoionization of neutral Ne was investigated just below the K edge. The chosen photon energy bandwidths were between 32 and 500 meV, facilitating the determination of natural line widths. The uncertainty of the energy scale is estimated to be 0.2 eV. For comparison with existing theoretical calculations, astrophysically relevant photoabsorption cross-sections were inferred by summing the measured partial ionization channels. Discussion of the observed resonances in the different final ionization channels reveals the presence of complex Auger-decay mechanisms. The ejection of three electrons from the lowest K-shell-excited Ne + ( s s p 1 2 2 S 2 6 2 1 2 ) level, for example, requires cooperative interaction of at least four electrons.

show abstract

Observation of a Four-Electron Auger Process in Near-K-Edge Photoionization of Singly Charged Carbon Ions

Cited by 71 publications

References 27 publications

Near-K-edge single, double, and triple photoionization ofC+ions

Near-K-edge single, double, and triple photoionization ofC+ions

Prominent role of multielectron processes inK-shell double and triple photodetachment of oxygen anions

Photoionization of Ne Atoms and Ne⁺ Ions Near the K Edge: PrecisionSpectroscopy and Absolute Cross-sections

Contact Info

Product

Resources

About

Observation of a Four-Electron Auger Process in Near-K-Edge Photoionization of Singly Charged Carbon Ions

Cited by 71 publications

References 27 publications

Near-K-edge single, double, and triple photoionization ofC+ions

Near-K-edge single, double, and triple photoionization ofC+ions

Prominent role of multielectron processes inK-shell double and triple photodetachment of oxygen anions

Photoionization of Ne Atoms and Ne+ Ions Near the K Edge: PrecisionSpectroscopy and Absolute Cross-sections

Contact Info

Product

Resources

About

Photoionization of Ne Atoms and Ne⁺ Ions Near the K Edge: PrecisionSpectroscopy and Absolute Cross-sections