INVESTIGADORES
SANCHEZ Hector Jorge
congresos y reuniones científicas
Título:
Energy Dispersive X-Ray Diffraction with Polycapillary Optics in a Three-Dimensional Confocal Setup
Autor/es:
R.D. PÉREZ; H. J. SÁNCHEZ; C..A. SOSA; MARÍA LUISA CARVALHO; C. A. PÉREZ
Lugar:
Coimbra
Reunión:
Conferencia; EXRS 2010; 2010
Resumen:
The confocal setup consists of x-ray lenses
in the excitation as well as in the detection channel. In this configuration, a
micro volume defined by the overlap of the foci of both x-ray lenses is
analyzed. Scanning this micro volume through the sample, 1-3 dimensional
studies can be performed. For depth profiling studies, only the scan of the
confocal volume in the normal direction to the sample is required. An elemental
analysis is obtained by the detection of the x-ray fluorescence produced in the
confocal volume [1]. In addition, Energy Dispersive X-Ray Diffraction analysis (EDXRD)
in the confocal volume can be performed using a continuous polychromatic source
and an appropriated fixed geometry based on a low divergence optic [2].
To implement the confocal setup, we used two
monolithic semi-polycapillaries in the excitation and detection channel. The
polycapillaries were made by means of drawing of multibundles of borosilicate
glass capillaries in a heating furnace. Our last prototypes produced an average
spot size of 70µm and an average transmission efficiency of 30%, which gives an
average gain of 450. The experiment was carried out at the D09B beamline of the
Brazilian Synchrotron Light Laboratory (Laboratório Nacional de Luz Síncrotron,
LNLS) using white beam. A silicon drift X-ray detector of 150 eV resolution at
5.9 keV was used for detection of scattered photons. A detailed
characterization of our confocal setup is described in this work. Structural
micro-EDXRD analyses of several stratified samples are shown.
References
[1] Vekemans, B., et. al. J. Anal. At.
Spectrom.,19, 1302 (2004).
[2] Bjeoumikhov, A., et. al. Appl. Phys.
Lett., 86, 144102 (2005).