Hi.
I am a master student in Turkey and my thesis is related to the
(e,2e) technique in obtaining information on both structure and
collision dynamics and the electron impact spectroscopy: from atom to
solids.

The possibility of investigating the electronic structure of solids
is largely based at present upon measurements of excitation energies
and transition probabilities. In spite of the large number of
spectroscopies currently used to characterize the electronic
structure of surfaces, none of them is capable of measuring momentum
distributions. Although it is very sensitive to fine details of the
wavefunction, the electron momentum density is not as widely
investigated as the other observables because ionization experiments
are needed to measure it, with completely determined kinematics.
Coincidence experiments of this kind, in particular (e,2e) and
coincidence Compton scattering experiments are the only available
spectroscopies capable of providing both binding energies and
momentum densities of the single particle states of the quantum
system under study.

The (e,2e) spectroscopy and the coincidence Compton scattering have
already shown their capability to investigate bulk properties of
solids. In particular, (e,2e) has already produced a fairly large
body of resuls on thin film momentum distributions. As far as
coincidence Compton experiments are concerned, it must be noted that
because of the smallnes of the cross section they are becoming
feasible and available for massive investigations only with the
advent of third-generation synchrotron sources. Their energy
resolution, however, is still not as goos as in the (e,2e)
experiments.

Best regards

Omer Sise
Department of Physics
Afyon Kocatepe University