Radiation Internal and External to the Ge Atom
C.J. Sparks, T. Gog, G.E. Ice (ORNL), R.A. Eisenhower (U. of Illinois)
NSLS Beamline X14A
Radiation Internal and External to the Ge Atom
C.J. Sparks, T. Gog, G.E. Ice (ORNL), R.A. Eisenhower (U. of Illinois)
NSLS Beamline X14A
A low-energy satellite to K
fluorescence has long been observed,
which has been shown to result from the emission of \bf two electrons and
one photon.1 This radiative Auger effect challenges our understanding of
x-ray excitation and decay processes. Despite the identification of the
radiative Auger effect for almost 30 years, no previous measurements have
been made of the energy dependent behavior of the radiative Auger effect.
All previous experiments were performed with incident
photon and electron energies far above an absorption edge.1
Our experiment compares the inelastic scattering from a Ge sample excited
by synchrotron radiation tuned to the Ge K
energy (9876 eV) to
the inelastic scattering from the same Ge sample excited by synchrotron
radiation tuned near and above the K edge (11103 eV). Above threshold, the
atom interacts with both the primary radiation field (11103 eV) and the self
emitted Ge K
fluorescence (9876 eV). As shown in Fig. 1,
there is a marked energy shift between the inelastic spectra excited above
and below threshold in the vicinity of the radiative Auger satellite. The
measurements with the sample excited by 9876 eV x-rays contain a resonant
Raman scattering peak in the vicinity of the radiative Auger satellite
energy. This asymmetric peak results from a resonant excitation of the K
hole and subsequent filling of the hole by an L electron.2 Hence the
resonant Raman line is designated the Ge K-L resonant Raman peak. The
measurements at and above threshold include both resonant Raman scattering
and the radiative Auger satellite. As illustrated in Fig. 1, there is
80 eV difference in energy at the leading edges marked by arrows.
[1] T. Aberg, J. Utriainen, Phys. Rev. Lett. \bf 22, 1346 (1969);
O. Keski-Rahkonen, J. Utriainen, J. Phy. \bf B7, 55 (1974)
[2] C.J. Sparks, Phys. Rev. Lett. \bf 33, 262 (1974)
Abstract Number: GOX14A1443E
Figure 1:
Inelastic resonant scattering from a Ge crystal excited with x-rays of energies which differ from the Ge K edge of 11103 eV by the energies shown. The incident energy for the resonant Raman curve labeled -1227 eV is Ge K at 11103 eV - 1227 eV = 9876 eV which is the Ge K
energy.
