Spectroscopic Measurement of L X-Rays Emitted by ²⁴¹Am Source by TES Microcalorimeter

Abstract

Nondestructive plutonium monitoring during reprocessing of spent nuclear fuel and in mixed-oxide-fuel fabrication facilities is expected to require spectroscopic measurements of L X-rays ranging from 10 to 20 keV. To this end, L X-ray emission intensities of transuranium elements will be important parameters in estimating the plutonium isotopic composition from L X-ray spectra. However, owing to fine structure within the L X-ray spectra, significant discrepancies exist among theoretical values, reference and experimental data concerning these emission intensities. To obtain better spectroscopic measurements, we used a TES microcalorimeter to get the energy spectrum of L X-rays emitted by ²³⁷Np resulting from α-decay of a ²⁴¹Am source. Values for the L X-ray emission intensities were estimated by analyzing the spectral data and compared with previous data. We advocate for improvements in evaluation of emission intensities given the enhanced precision afforded by TES microcalorimetry.