RESONANCE AND THRESHOLD EFFECTS IN POLARIZED X-RAY-EMISSION FROM ATOMS AND MOLECULES

[摘要] Strongly anisotropic and polarized K-V (valence to K-vacancy) X-ray emission has been observed from gas-phase molecules following excitation of a K-shell electron to valence-like subthreshold resonances using a narrow bandwidth, linearly polarized X-ray beam. Distinctively different polarizations and angular distributions are observed for emission involving molecular orbitals of different symmetries. A classical model of the X-ray absorption/emission process accurately describes the observed radiation pattems. Relatively weak polarizations and anisotropies are observed following excitation of atomic subthreshold resonances, due to averaging over unresolved final states. However, resonance and threshold studies of atomic X-ray spectra illustrate the inelastic resonance scattering process and the onset of characteristic fluorescence.

[发布日期] 1994-04-01

[效力级别]  Proceedings Paper