Search results for "Neutrons"
showing 10 items of 152 documents
Experimental neutron capture data of 58Ni from the CERN n_TOF facility
2014
The $^{58}$Ni $(n,\gamma)$ cross section has been measured at the neutron time of flight facility n_TOF at CERN, in the energy range from 27 meV up to 400 keV. In total, 51 resonances have been analyzed up to 122 keV. Maxwellian averaged cross sections (MACS) have been calculated for stellar temperatures of kT$=$5-100 keV with uncertainties of less than 6%, showing fair agreement with recent experimental and evaluated data up to kT = 50 keV. The MACS extracted in the present work at 30 keV is 34.2$\pm$0.6$_\mathrm{stat}\pm$1.8$_\mathrm{sys}$ mb, in agreement with latest results and evaluations, but 12% lower relative to the recent KADoNIS compilation of astrophysical cross sections. When in…
Analysis of the Photoneutron Field Near the THz Dump of the CLEAR Accelerator at CERN With SEU Measurements and Simulations
2022
We study the radiation environment near the terahertz (THz) dump of the CERN Linear Electron Accelerator for Research (CLEAR) electron accelerator at CERN, using FLUktuierende KAskade in German (FLUKA) simulations and single-event upset (SEU) measurements taken with 32-Mbit Integrated Silicon Solution Inc. (ISSI) static random access memories (SRAMs). The main focus is on the characterization of the neutron field to evaluate its suitability for radiation tests of electronics in comparison with other irradiation facilities. Neutrons at CLEAR are produced via photonuclear reactions, mostly initiated by photons from the electromagnetic cascades that occur when the beam is absorbed by the dump …
0.1-10 MeV Neutron Soft Error Rate in Accelerator and Atmospheric Environments
2021
Neutrons with energies between 0.1-10 MeV can significantly impact the Soft Error Rate (SER) in SRAMs manufactured in scaled technologies, with respect to high-energy neutrons. Their contribution is evaluated in accelerator, ground level and avionic (12 km of altitude) environments. Experimental cross sections were measured with monoenergetic neutrons from 144 keV to 17 MeV, and results benchmarked with Monte Carlo simulations. It was found that even 144 keV neutrons can induce upsets due to elastic scattering. Moreover, neutrons in the 0.1-10 MeV energy range can induce more than 60% of the overall upset rate in accelerator applications, while their contribution can exceed 18% in avionics.…
Proton Direct Ionization Upsets at Tens of MeV
2023
Experimental monoenergetic proton single-event upset (SEU) cross sections of a 65-nm low core-voltage static random access memory (SRAM) were found to be exceptionally high not only at low energies ($ 3 MeV and extending up to tens of MeV. The SEU cross Section from 20-MeV protons exceeds the 200-MeV proton SEU cross Section by almost a factor of 3. Similarly, monoenergetic neutron cross sections at 14 MeV are about a factor of 3 lower than the 20-MeV proton cross section. Because of Monte Carlo (MC) simulations, it was determined that this strong enhancement is due to the proton direct ionization process as opposed to the elastic and inelastic scattering processes that dominate the SEU res…
The Nuclear astrophysics program at n_TOF (CERN)
2017
An important experimental program on Nuclear Astrophysics is being carried out at the n_TOF since several years, in order to address the still open issues in stellar and primordial nucleosynthesis. Several neutron capture reactions relevant to s-process nucleosynthesis have been measured so far, some of which on important branching point radioisotopes. Furthermore, the construction of a second experimental area has recently opened the way to challenging measurements of (n, charged particle) reactions on isotopes of short half-life. The Nuclear Astrophysics program of the n_TOF Collaboration is here described, with emphasis on recent results relevant for stellar nucleosynthesis, stellar neut…
Improvement of ESR dosimetry for thermal neutron beams through the addition of gadolinium.
2007
In this paper, the addition of gadolinium is proposed as a useful tool to enhance the electron spin resonance (ESR) sensitivity of organic compounds to thermal neutrons. The target of this work is the detection, through the ESR technique, of the thermal neutron fluence in a mixed field of photons and neutrons. Gadolinium was chosen because it has a very high capture cross section to thermal neutrons; its nuclear reaction with thermal neutrons induces complex inner shell transitions that generate, besides other particles, Auger electrons, which in turn release their energy in the neighborhood (only several nanometers) of the place of reaction. Gadolinium was added to two organic molecules: a…
Measurement of the 241Am neutron capture cross section at the n-TOF facility at CERN
2016
New neutron cross section measurements of minor actinides have been performed recently in order to reduce the uncertainties in the evaluated data, which is important for the design of advanced nuclear reactors and, in particular, for determining their performance in the transmutation of nuclear waste. We have measured the 241 Am(n,γ) cross section at the n TOF facility between 0.2 eV and 10 keV with a BaF2 Total Absorption Calorimeter, and the analysis of the measurement has been recently concluded. Our results are in reasonable agreement below 20 eV with the ones published by C. Lampoudis et al. in 2013, who reported a 22% larger capture cross section up to 110 eV compared to experimental …
The Pion Single-Event Effect Resonance and its Impact in an Accelerator Environment
2020
International audience; The pion resonance in the nuclear reaction cross section is seen to have a direct impact on the single-event effect (SEE) cross section of modern electronic devices. This was experimentally observed for single-event upsets and single-event latchup. Rectangular parallelepiped (RPP) models built to fit proton data confirm the existence of the pion SEE cross-section resonance. The impact on current radiation hardness assurance (RHA) soft error rate (SER) predictions is, however, minimal for the accelerator environment since this is dominated by high neutron fluxes. The resonance is not seen to have a major impact on the high-energy hadron equivalence approximation estab…
Nuclear data activities at the n_TOF facility at CERN
2016
International audience; Nuclear data in general, and neutron-induced reaction cross sections in particular, are important for a wide variety of research fields. They play a key role in the safety and criticality assessment of nuclear technology, not only for existing power reactors but also for radiation dosimetry, medical applications, the transmutation of nuclear waste, accelerator-driven systems, fuel cycle investigations and future reactor systems as in Generation IV. Applications of nuclear data are also related to research fields as the study of nuclear level densities and stellar nucleosynthesis. Simulations and calculations of nuclear technology applications largely rely on evaluate…
The 33S(n,α)30Si cross section measurement at n TOF-EAR2 (CERN): From 0.01 eV to the resonance region
2017
The 33S(n,α)30Si cross section measurement, using 10B(n,α) as reference, at the n TOF Experimental Area 2 (EAR2) facility at CERN is presented. Data from 0.01 eV to 100 keV are provided and, for the first time, the cross section is measured in the range from 0.01 eV to 10 keV. These data may be used for a future evaluation of the cross section because present evaluations exhibit large discrepancies. The 33S(n,α)30Si reaction is of interest in medical physics because of its possible use as a cooperative target to boron in Neutron Capture Therapy (NCT).