Energy Dependence of Tungsten-Dominated SEL Cross Sections

SEL Hardness Assurance in a Mixed Radiation Field

“…In [9] however, the warning is given that for components with a strong SEL cross section energy dependence, most test facilities will underestimate the failure rate for the natural atmospheric environment. This was also shown to be the expected scenario through calculations for the high-energy accelerator environment [3], [10] in which the particle energy spectra can be of a very hard (i.e. energetic) character.…”

“…8, corresponding to a volume of ∼0.5 µm 3 per cell. This value was in fact predicted in [10] through a fit of the Monte Carlo SEL model to the experimental data in the 100-230 MeV range. The impact of the energy dependency derived from the high-Z elements on the mixed-field cross sections (initially introduced in [12]) will be quantified in the following subsection.…”

“…Their respective characteristics are shown in Table II together with the naming convention used in the present paper, selected in order to be consistent with that used in [3], [10]. In order to characterize their SEL response, the memories were powered and their current consumption was monitored with a frequency of 1 Hz through a LabVIEW interface.…”

“…For SRAMs C and D, the calculation approach is different owing to their relatively low cross section, which meant it was not possible to obtain a statistically meaningful number of counts (> 50) for energies below 150 MeV. For this reason, we use the output of the Monte Carlo based semi-empirical SEL model introduced in [10] and that will be briefly covered in subsection IV-B to estimate the cross section in the 30-100 MeV range. As was performed for SRAMs A and F, we initially assume that the SEL cross section saturates at the maximum energy tested for at PSI (i.e.…”

“…In the present study, measurements performed in the VESU-VIO beam at ISIS [11] and the CERN High-energy Accelerator Mixed field facility (CHARM) are used in combination with the model we introduced in [10] and applied in [3] in order to quantify the risk of underestimating the natural atmospheric and high-energy accelerator failure rates derived from monoenergetic proton tests, thus providing safety margins to be applied to the experimental results. In addition, ground-level and avionics failure rates from neutron spallation test results are typically derived by scaling the experimental rate with the respective fluxes above 10 MeV [4].…”