### Abstract

Angular distribution of emitted photoelectrons is theoretically studied for high-energy X-rays where electric quadrupole and magnetic dipole transitions play some important roles in addition to the electric dipole transitions. We apply irreducible tensor expansion of photon field to discuss the high-energy photoelectron angular distribution instead of the usual power series expansion. The present numerical calculations show that the conventional power series expansion works so well up to quite high energy (≈10 keV) for core excitation. Photoelectron diffraction effects make the nondipole contribution sensitive to the geometrical setup of surrounding scattering atoms because of the strong focusing effect in the high-energy region. Total high-energy photoemission intensities from extended levels are well described by use of the Gelius formula because the interference terms are effectively smeared out by Debye-Waller factors.

Original language | English |
---|---|

Pages (from-to) | 14-23 |

Number of pages | 10 |

Journal | Journal of Electron Spectroscopy and Related Phenomena |

Volume | 159 |

Issue number | 1-3 |

DOIs | |

Publication status | Published - Jun 2007 |

### Fingerprint

### Keywords

- Debye-Waller factor
- Gelius formula
- High-energy XPS
- Irreducible tensor
- Nondipole excitation
- Photoelectron diffraction

### ASJC Scopus subject areas

- Physical and Theoretical Chemistry
- Spectroscopy
- Atomic and Molecular Physics, and Optics
- Surfaces and Interfaces

### Cite this

*Journal of Electron Spectroscopy and Related Phenomena*,

*159*(1-3), 14-23. https://doi.org/10.1016/j.elspec.2007.02.023

**Nondipole effects in photoemission angular distribution excited by high-energy X-rays.** / Fujikawa, Takashi; Suzuki, Rie; Arai, Hiroko; Shinotsuka, Hiroshi; Kövér, L.

Research output: Contribution to journal › Article

*Journal of Electron Spectroscopy and Related Phenomena*, vol. 159, no. 1-3, pp. 14-23. https://doi.org/10.1016/j.elspec.2007.02.023

}

TY - JOUR

T1 - Nondipole effects in photoemission angular distribution excited by high-energy X-rays

AU - Fujikawa, Takashi

AU - Suzuki, Rie

AU - Arai, Hiroko

AU - Shinotsuka, Hiroshi

AU - Kövér, L.

PY - 2007/6

Y1 - 2007/6

N2 - Angular distribution of emitted photoelectrons is theoretically studied for high-energy X-rays where electric quadrupole and magnetic dipole transitions play some important roles in addition to the electric dipole transitions. We apply irreducible tensor expansion of photon field to discuss the high-energy photoelectron angular distribution instead of the usual power series expansion. The present numerical calculations show that the conventional power series expansion works so well up to quite high energy (≈10 keV) for core excitation. Photoelectron diffraction effects make the nondipole contribution sensitive to the geometrical setup of surrounding scattering atoms because of the strong focusing effect in the high-energy region. Total high-energy photoemission intensities from extended levels are well described by use of the Gelius formula because the interference terms are effectively smeared out by Debye-Waller factors.

AB - Angular distribution of emitted photoelectrons is theoretically studied for high-energy X-rays where electric quadrupole and magnetic dipole transitions play some important roles in addition to the electric dipole transitions. We apply irreducible tensor expansion of photon field to discuss the high-energy photoelectron angular distribution instead of the usual power series expansion. The present numerical calculations show that the conventional power series expansion works so well up to quite high energy (≈10 keV) for core excitation. Photoelectron diffraction effects make the nondipole contribution sensitive to the geometrical setup of surrounding scattering atoms because of the strong focusing effect in the high-energy region. Total high-energy photoemission intensities from extended levels are well described by use of the Gelius formula because the interference terms are effectively smeared out by Debye-Waller factors.

KW - Debye-Waller factor

KW - Gelius formula

KW - High-energy XPS

KW - Irreducible tensor

KW - Nondipole excitation

KW - Photoelectron diffraction

UR - http://www.scopus.com/inward/record.url?scp=34249107347&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=34249107347&partnerID=8YFLogxK

U2 - 10.1016/j.elspec.2007.02.023

DO - 10.1016/j.elspec.2007.02.023

M3 - Article

AN - SCOPUS:34249107347

VL - 159

SP - 14

EP - 23

JO - Journal of Electron Spectroscopy and Related Phenomena

JF - Journal of Electron Spectroscopy and Related Phenomena

SN - 0368-2048

IS - 1-3

ER -