Gas phase VUV single-photon photoionization spectroscopy of electrospray-produced multiply protonated cytochrome c protein (12 kDa) has been performed by means coupling a linear quadrupole ion trap with synchrotron beamline. The thresholds for the ionization 8+ and 11+ charge state precursors to radical 9+ 12+ species were measured be 12.75 ± 0.10 13.51 eV, respectively.

Photoelectron spectrometry has been used for the first time to study autoionization of photoexcited hollow lithium atoms into various continua ${\mathrm{Li}}^{+}$ ion. Absolute values partial photoionization cross sections have determined. The R-matrix approximation also calculate energies states as well all sections. Experimental and theoretical results are in very good agreement.

We present absolute L-shell photoionisation cross sections for the S+, S2+, S3+ions. The were obtained using monochromatised photon beam delivered by SOLEIL synchrotron source coupled with an ion extracted from electron cyclotron resonance (ECRIS) in merged dual-beam configuration. single, double and triple ionisation measured combined to generate total sections. For each of S3+ ions, energy regions corresponding excitation a 2p or 2s (175-230 eV) investigated. experimental results are...

Abstract We present absolute L-shell photoionisation cross sections for the S+, S2+, S3+ ions. The were obtained using monochromatised photon beam delivered by SOLEIL syn- chrotron source coupled with an ion extracted from electron cyclotron resonance (ECRIS) in merged dual-beam configuration. single, double and triple ionisation measured combined to generate total sections. For each of S2+ ions, energy regions corresponding excitation a 2p or 2s (∼ 175-230 eV) investigated. experimental...

Photoelectron data are reported for the first measurement of even-parity hollow lithium states produced by triple photoexcitation laser-excited atoms. Calculations using R-matrix approximation energy these and partial photoionization cross sections also reported. Experiment theory in excellent agreement on a relative scale.

Using synchrotron radiation, we have investigated, over an extended photon energy range, the full photoelectron spectrum following ionization in 2p subshell of Na atoms laser excited into 2${\mathit{p}}^{6}$3${\mathit{p}}^{2}$${\mathit{P}}_{3/2}$ state. We determined relative cross sections for leaving positive ions various final states, corresponding to main line and satellite lines. In particular, observed a strong enhancement intensity shakeup satellites atom. Our measurements allow...

Experiment and theory have been used to determine the final-state symmetry for $n=2$ state in photoionized helium. The angular asymmetry parameter $\ensuremath{\beta}$ has measured as a function of photon energy by means angle-resolved photoelectron spectroscopy. From these values, which are weighted average ${\ensuremath{\beta}}_{2s}$ ${\ensuremath{\beta}}_{2p}$, together with theoretical values ${\ensuremath{\beta}}_{2p}$ ${\ensuremath{\beta}}_{2s}$, ratio, $R$, partial $2p$...

Spectral probes for the ${\mathrm{CH}}^{+}, {\mathrm{OH}}^{+}$, and ${\mathrm{SiH}}^{+}$ hydride molecular ions that play key roles in astrophysics plasma processes are presented. The merged-beam technique at SOLEIL synchrotron was used to record photoionization (ion yield) spectra of their parent atomic ions, $K$-shell $L$-shell regions, respectively. Energies oscillator strengths $K\ensuremath{\alpha}$ (${\mathrm{CH}}^{+}$ ${\mathrm{OH}}^{+}$) $L\ensuremath{\alpha}$ (${\mathrm{SiH}}^{+}$)...

Photoelectron data for hollow lithium states obtained with unprecedented high spectral resolution and sensitivity are presented. A critical comparison is made the most recent theoretical results. Partial cross sections measured providing first definitive test of advanced ab initio calculations this highly excited four-body atomic system.

We present detailed experimental results for the resonance structure of atomic Ca in region 3p threshold, from 26 to 40 eV, as manifested partial cross sections 4${s}^{\mathrm{\ensuremath{-}}1}$ and 3${p}^{\mathrm{\ensuremath{-}}1}$ main photoelectron lines several their satellites, including satellite--to--main-line branching ratios. also photoionization 4${s}^{\mathrm{\ensuremath{-}}1}$, 3${p}^{\mathrm{\ensuremath{-}}1}$, 3${s}^{\mathrm{\ensuremath{-}}1}$ up 120 eV photon energy. Finally,...

Photoionization cross sections of halogen-like Kr+ and Xe+ ions have been measured in the photon energy range extending up to 15 eV above threshold. Two different devices were used, a merged-beam set-up an ion trap. Combination two techniques allows for extraction pure ground state ionization section on absolute scale. Multiconfiguration Dirac–Fock calculations reproduce magnitude direct photoionization well.

Measurements of absolute cross sections for the K-shell photoionization B-like atomic nitrogen ions were carried out utilizing ion–photon merged-beam technique at SOLEIL synchrotron radiation facility in Saint-Aubin, France. High-resolution spectroscopy with E/ΔE ≈13,500 was maximum resolution achieved. We have investigated two photon energy regions: 404–409 eV and 439–442 eV. Resonance peaks found experimental measured are compared theoretical estimates from multi-configuration Dirac–Fock,...

Absolute cross-sections for the K-shell photoionization of Be-like (O4 +) and Li-like (O5 atomic oxygen ions were measured first time (in their respective regions) by employing ion–photon merged-beam technique at SOLEIL synchrotron-radiation facility in Saint-Aubin, France. High-resolution spectroscopy with E/ΔE ≈ 3200 (≈170 meV, full width half-maximum) was achieved photon energy from 550 to 670 eV. Rich resonance structure observed experimental spectra is analysed using R-matrix...

Absolute cross sections for the K-shell photoionization of Be-like and Li-like atomic nitrogen ions were measured by employing ion–photon merged-beam technique at SOLEIL synchrotron radiation facility in Saint-Aubin, France. High-resolution spectroscopy nominal resolutions 38, 56, 111, 133 meV full width half maximum (FWHM) 125 FWHM was achieved photon energies ranging from 410 up to 460 eV. The experimental measurements are compared with theoretical estimates multi-configuration Dirac–Fock,...

The complete electron spectra caused by photoionisation of Li and Na vapour in the 1s 2p shells respectively, have been investigated region from 5 eV above threshold up to about twice binding energy ionised electron. Even though contribution molecules pressure was only order a few per cent, molecular features are found experimental with intensities comparable atomic structures. interpretation all observed spectrum is given. In specific regions, where contributions do not disturb ones,...

Coupling an ion trap with synchrotron radiation is shown here to be a powerful approach measure photoionization cross sections on ionic species relaxed in their ground state. The efficiency curve of Xe+ ions stored Fourier transform cyclotron resonance was recorded at ELETTRA the 20-23 eV photon energy range. Absolute were derived by comparison yield measurements from ASTRID merged-beam experiment. Multiconfiguration Dirac-Fock calculations performed for interpretation these new data.

We present measurements of the absolute photoionization cross section aluminumlike ${\mathrm{Si}}^{+}$ ion over 94--137 eV photon energy range. The were performed using merged-beam setup on PLEIADES beamline at SOLEIL synchrotron radiation facility. Signals produced in ${\mathrm{Si}}^{2+}$ and ${\mathrm{Si}}^{3+}$ channels $2p$ subshell from both $1{s}^{2}2{s}^{2}2{p}^{6}3{s}^{2}3p{\phantom{\rule{0.16em}{0ex}}}^{2}{P}_{1/2,3/2}$ ground levels...

Absolute cross sections for the {\it K}-shell photoionization of boron-like (B-like) O$^{3+}$ ions were measured by employing ion-photon merged-beam technique at SOLEIL synchrotron-radiation facility in Saint-Aubin, France. High-resolution spectroscopy with E/$\Delta$E $\approx$ 5000 ($\approx$ 110 meV, FWHM) was achieved photon energy from 540 eV up to 600 eV. Several theoretical approaches, including R-Matrix, Multi-Configuration Dirac-Fock and Screening Constant Unit Nuclear Charge used...

Several extended Rydberg series have been experimentally identified in triply excited states of hollow lithium, by use electron spectrometry and synchrotron radiation at the Advanced Light Source. Energies, partial cross sections, quantum defects also calculated using $R$-matrix approximation. Our results show that two inner electrons stay a core-excited state given symmetry while behavior third is mostly governed nuclear potential screened electrons.

We have measured the absolute photoionization cross sections of ${\text{Fe}}^{2+}$ to ${\text{Fe}}^{6+}$ ions in photon energy range covering first ionization threshold up 160 eV. Particular interest is emphasized on region $3p\ensuremath{\rightarrow}3d$ excitations. The experimental data are compared results calculations we performed using a spectral opacity code, as well available $R$-matrix and one-electron calculations. It shown that often theoretical tend overestimate intensity...

This article presents N2+ fragment yields following nitrogen K-shell photo-absorption in the NH+ molecular ion measured at SOLEIL synchrotron radiation facility photon energy region 390–450 eV. The combination of high sensitivity merged-beam, multi-analysis apparatus (MAIA) with spectral resolution PLEIADES beamline helped to resolve experimentally vibrational structures highly excited [N1s−1H]*+ electronic states closed or open-shell configurations. assignment observed features was achieved...

Absolute photoionization cross sections of Ar${}^{+}$, Ar${}^{2+}$, and Ar${}^{3+}$ ions have been measured in the 250--280 eV photon energy range. These results are compared to theoretical extracted from two new calculations we performed. They reproduce well general behavior experimental spectra magnitude direct sections. However, oscillator strength resonant structure spectra, dominated by $2p\ensuremath{\rightarrow}3d$ transitions, is overestimated up 80$%$ our calculations.

We have studied photoionization in the inner valence $3s$ subshell of K and spectroscopic properties two $3{s}^{\ensuremath{-}1}\phantom{\rule{0.28em}{0ex}}(^{1}S)$ $(^{3}S)$ resulting states. Similar to Rb Cs cases, lifetime widths $(^{1}S)$ states are found be markedly different, due electron correlation effects. The main part study deals with subsequent Auger decay $3{s}^{\ensuremath{-}1}$ states, which particularity involve low energy...