Determination of Uranium enrichment with FRAM - comparison of electrically cooled Germanium detector Detective200 and U-Pu detector

In the context of fissile material detection, the determination of Uranium enrichment and of the Plutonium isotopic vector is tremendously important. The negligence of such information may lead to drastic if not fatal consequences to the general public in case the material in question is used in explosive devices such as an Improvised Nuclear Devices (IND). The implemented automatic analysis routine of the electrically cooled Detective 200 detector has been investigated in earlier measurements measuring Uranium and plutonium sources of different enrichment respectively isotopic composition. The results have been partly disappointing. The object of the present work was to investigate the general ability and the quality of the spectra obtained with the Detective200 in comparison to the commonly used U-Pu detectors cooled with liquid nitrogen. To determine the uranium enrichment measurements were carried out with a source of depleted Uranium and different shielding materials. The evaluation of the spectra was performed with the isotopic analysis code FRAM. The results for the Uranium enrichment for the Detective200 system were compared to the enrichment result of the commonly used U-Pu detectors. The results of these measurements and an assessment of the ability of the FRAM software combined with the Detective200 system in determining the Uranium enrichment will be presented.