Integration Of Power Spectrum Research Articles

Characterization of fluorescent nuclear track detectors as criticality dosimeters

Fluorescent nuclear track detectors (FNTDs) are suggested for criticality dosimetry of neutrons and photons. The depth profiles of the fluorescent signal from FNTDs after exposure to high doses of broad spectrum neutron fields from four different sources are analyzed using the power spectrum integral (PSI) measured at increasing depths within the Al2O3:C,Mg crystals. The depth profiles are compared to Monte Carlo simulations of energy deposition of recoil protons as a function of depth in aluminum oxide for the same four neutron sources. An algorithm for estimating the median neutron energy and neutron dose correction factors was developed. The application of FNTDs for criticality excursion accidents is discussed.

Evaluation of aluminum oxide fluorescent and OSL detectors in proton radiotherapy beams

Fluorescent Nuclear Track Detectors (FNTD) and Optically Stimulated Luminescence Detectors (OSLD) were investigated for application in proton therapy dosimetry. FNTDs and OSLDs are made of Al2O3:C,Mg single crystals and Al2O3:C powder, respectively. The detectors were irradiated in water, behind different thicknesses of plastic slabs and behind wedge shaped plastic absorbers. FNTDs positioned behind different thicknesses of plastic slabs and in water phantom show Bragg curves with a peak to entrance ratio of eight compared to about three from ionization chamber measurements. The over-response of FNTDs is attributed to the non-linear response of the power spectrum integral (PSI) parameter as a function of proton linear energy transfer (LET). The limitations of the wedge absorber experiment due to lateral proton straggling are discussed. Experimental data and image simulations were utilized to obtain LET dependencies for the FNTD power spectrum integral and fluorescence amplitude.