Fluorescent Nuclear Track Detector (FNTD) technology was tested as an imaging and spectroscopic tool for radionuclide analysis. This investigation intended to distinguish between characteristic α-particles of 239Pu (5.2 MeV), 234U (4.8 MeV) and 238U (4.2 MeV). FNTDs are Al2O3:C,Mg single crystals with color centers that undergo radiochromic transformation. FNTD readout is non-destructive and is performed with laser scanning confocal fluorescent microscopy. Ionization events register in the detector as bright fluorescent features on a weak fluorescent background. Images were acquired at several incrementing depths in the detector to produce 3D data sets. Spectroscopic information was obtained by measuring α-particle range in the detector after 3D image reconstruction. The resolution of this technique is fundamentally limited by particle range straggling (about 3.8 % (k=1) at these α-particle energies). The spectroscopic line-width as full width at half maximum (FWHM) was determined to be 0.4 MeV enabling discrimination between the isotopes of interest.
Citation: Radiation Measurements
Pub Type: Journals
fluorescence, laser scanning confocal microscopy, imaging, hot particles, alpha particles, spectroscopy, aluminum oxide