Performance of a grating monochromator at BL27SU beamline of SPring-8 in the higher energy region

Tamenori, Y.; Ohashi, Haruhiko; Ishiguro, Eiji; Ishikawa, Tetsuya

doi:10.1063/1.1423782

Cited by 59 publications

(24 citation statements)

References 13 publications

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“…The radiation source is a figure-8 undulator, whose emitted radiation is linearly polarized either in the horizontal plane of the storage ring (first order) or in the vertical plane perpendicular to it (0.5th order) [12]. The Hettrick-type monochromator of this beamline can provide soft x rays in the range 150 eV to 2.5 keV, with very narrow photon bandwidth at a resolution up to 14 000 [13,14]. The electron spectroscopy apparatus consists of a hemispherical electron analyzer (Gammadata-Scienta SES-2002), a gas cell, and a differentially pumped chamber [15].…”

Section: Methodsmentioning

confidence: 99%

Interplay of different partial waves on vibrationally resolved photoionization of the OKshell of the CO molecule

et al. 2004

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The asymmetry parameter ␤ for the O K shell photoemission of the CO molecule has been measured for different vibrational states of the residual ion. The corresponding calculations performed by us in the relaxed core Hartree-Fock approximation are in qualitative agreement with the experiment. From the analysis of theoretical data, we made the conclusion that the variation of ␤ with the vibrational quantum number is connected with different dependences of the dipole matrix elements in the s, d, and f channels on the internuclear distance R in the * shape resonance.

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Section: Methodsmentioning

confidence: 99%

Interplay of different partial waves on vibrationally resolved photoionization of the OKshell of the CO molecule

et al. 2004

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“…The present experiment has been carried out on the c branch of the high-resolution photochemistry beamline 27SU [20][21][22] at SPring-8, the 8 GeV synchrotron radiation facility in Japan. The radiation source is a figure-8 undulator [23].…”

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confidence: 99%

Photoelectron recapture as a tool for the spectroscopy of ionic Rydberg states

et al. 2004

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We use recapture of near-threshold photoelectrons by postcollision interaction with Auger electrons as an effective method for population of the high-Rydberg states of subvalence ionized Ne ions. The subsequent intermultiplet Auger transitions are detected by high-resolution electron spectrometry. The series of transitions 2p 4 ͑ 1 D͒np 2 D , 2 F → 2p 4 3 P up to n = 20 are observed and identified with the help of multiconfiguration Dirac-Fock ab initio calculations.Spectroscopic data on atomic ions are required for modeling of stellar atmospheres as well as for laboratory plasmas with their relevance for fusion reactors. Experimentally, the spectroscopic study of ions, in particular their electron spectroscopy, is a challenging task. In spite of big progress in this field (see, for example, a review by West [1]) there is still a need for the development of improved methods of spectroscopic investigation of atomic ions. The present methods currently existing for ion spectroscopy are always experimentally very challenging. In the past decade particular interest was attracted by a special class of autoionizing states of atomic ions, the so-called inner-valence excitations [2]. Consider, for example, a Ne + ion with a vacancy in the 2s subshell. A relaxation of this ion via "normal" Auger decay is energetically not allowed. However, if in the process of 2s ionization another electron is excited to a 3p or higher Rydberg orbital, such "two-hole one-particle" states may decay via the "participator" Auger transition [2,3]. Especially interesting are the transitions in which the two-hole configuration is not changed but only the core multiplets are different in the initial and final states. For example, in Ne + , due to a significant singlet-triplet splitting, the 2s2p 5 ͑ 1 P͒3p states lie above the 2s2p 5 3 P level of Ne 2+ and can decay to it. Such transitions, called valence multiplet changing or intermultiplet Auger transitions, are predominant in the low kineticenergy part of the spectrum and determine the large width of the inner-valence-excited ionic states [4][5][6][7][8][9].Spectroscopic information about these two-hole oneparticle states so far was mainly obtained by studies of the satellite structure in the subvalence shell photoionization [10]. The state of the art of such ionization + excitation experiments has recently been demonstrated by Bolognesi et al. [11]. They applied the technique of high-resolution threshold photoelectron spectroscopy to study the Ne + 2p 4 nᐉ satellite states and observed several Rydberg series, up to n =26 in some series. The energy positions and the quantum defects ␦ were determined. Although threshold photoelectron spectroscopy is indeed powerful, its application is limited to states which are coupled to the direct photoionization channel.In principle, singly charged inner-valence-excited configurations can also be reached by resonant Auger decay of a neutral core-excited state, such as the 1s −1 3p photoexcited state in Ne. As an advantage, states can be populated by resonan...

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“…Small-angle scattering measurements were performed at beamline 11A of the Photon Factory, KEK, and beamline 27SU of SPring8, Japan, using a set of gratings and curved mirrors (Ohashi et al, 2001;Tamenori et al, 2002, Kitajima, 2015. Measurements were made with a CCD detector provided by Hamamatsu Photonics Co. Ltd. A back-illuminated cooled CCD coupled with tapered fiber optics, with a P43 phosphor plate for use in the tender X-ray region, was adopted.…”

Section: Resultsmentioning

confidence: 99%

Realization of two-dimensional anomalous small-angle scattering of Al alloys at the K absorption edge of Al

et al. 2016

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Two‐dimensional anomalous small‐angle X‐ray scattering (ASAXS) measurements at the K absorption edge of Al have been successfully performed. Contrast change below the absorption edge was detected with the use of a CCD detector. The change of ASAXS intensities near the edge for alumina nanopowder and that for Guinier–Preston zones in an Al–Zn alloy were explained by the anomalous dispersion of Al. The present results showed that two‐dimensional SAXS measurements with a dynamic range extended to show Porod's law have been achieved for photon energies of about 1.5 keV with the use of a CCD detector optically coupled with a P43 phosphor plate.

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Performance of a grating monochromator at BL27SU beamline of SPring-8 in the higher energy region

Cited by 59 publications

References 13 publications

Interplay of different partial waves on vibrationally resolved photoionization of the OKshell of the CO molecule

Interplay of different partial waves on vibrationally resolved photoionization of the OKshell of the CO molecule

Photoelectron recapture as a tool for the spectroscopy of ionic Rydberg states

Realization of two-dimensional anomalous small-angle scattering of Al alloys at the K absorption edge of Al

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