Keywords:
radiation transport
inverse problem
x-ray spectrometry
detector response function
radiation detectors
non-destructive techniques
x and gamma ray dosimetry
Radiation transport modelling (using deterministic and Monte Carlo
methods) of polarised and non-polarised photons, and charged and
neutral particles Problems of multiple scattering. Coupled
transport of photons and particles. Detailed representation of the
detector influence and the pulse pile-up. Inverse problem. Applications to x- and
gamma-ray spectroscopy (EDXRS, XANES, electron microprobe, tomography), to medical physics, to environmental physics, to
industrial diagnostics, and to cultural heritage (non-destructive
techniques).
The study of multiple scattering is important in x- and gamma-ray
spectrometry. The contribute of only few scattering orders,
computed deterministically by using the transport theory, allows
the build-up of a theoretical spectrum which looks very close to
the experimental one, favouring its interpretation. The
Montecuccolino's research group has performed systematic studies of
the multiple scattering contributions to the x-ray spectrum, which
have lead to the development of a computer code to analyse
experimental spectra (the code SHAPE) which includes all the
deterministic solutions calculated with the scalar model. Recently,
the transport model has been enriched with an analytical
formulation which describes the polarisation state of the photons
at every point of the phase space during the diffusion. This
addition has permitted to study the influence of a source having an
arbitrary polarisation state, and how this state will evolve as a
consequence of the interactions undergone into the mean. Recent
results have been the excellent agreement with spectra produced by
linearly polarised sources like the synchrotron light. It has been
developed a Monte Carlo code inspired on the vector transport
model. It has been developed a 3-D version of the Monte Carlo code
which has given its first results, recently. The validity of the
transport model developed has been widely verified in the different
application frameworks of x-ray spectrometry, specially in relation
to the non destructive techniques using x-rays for the
determination of some properties of the materials and in X-ray
imaging and dosimetry.
