Maxwellian-averaged cross-sections (MACS) are needed as an input for the models of stellar s- and r-processes nucleosynthesis. MACS can be obtained from activation measurements, irradiating a sample with the neutron field generated by the 7Li(p,n)7Be reaction at 1912 keV proton energy. At this energy, the neutron energy spectrum is close...
-
February 1, 2023 (v1)PublicationUploaded on: February 22, 2023
-
December 1, 2016 (v1)Publication
We present some open questions in nucleosynthesis focused on the measurement of relevant neutron capture cross-sections and on new experimental methods. We review the recent 63Ni(n,γ) experiment carried out at the n_TOF facility at CERN and its astrophysical implications as well as future experiments and opportunities at n_TOF. We argue some...
Uploaded on: December 4, 2022 -
April 20, 2020 (v1)Publication
Neutron-induced reactions are studied at the neutron time-of-flight facility n-TOF at CERN. The facility uses 6∼ns wide pulses of 20 GeV/c protons impinging on a lead spallation target. The large neutron energy range and the high instantaneous neutron flux combined with high resolution are among the key characteristics of the facility. After a...
Uploaded on: December 4, 2022 -
December 1, 2016 (v1)Publication
Above 1 MeV of incident neutron energy the fission fragment angular distribution (FFAD) has generally a strong anisotropic behavior due to the combination of the incident orbital momentum and the intrinsic spin of the fissioning nucleus. This effect has to be taken into account for the efficiency estimation of devices used for fission cross...
Uploaded on: March 1, 2023 -
December 1, 2016 (v1)Publication
The neutron capture cross section of 58Ni was measured at the neutron time of flight facility n_TOF at CERN, from 27 meV to 400 keV neutron energy. Special care has been taken to identify all the possible sources of background, with the so-called neutron background obtained for the first time using high-precision GEANT4 simulations. The energy...
Uploaded on: March 27, 2023 -
November 30, 2016 (v1)Publication
The radiative capture cross section of 238U is very important for the developing of new reactor technologies and the safety of existing ones. Here the preliminary results of the 238U(n,γ) cross section measurement performed at n_TOF with C6D6 scintillation detectors are presented, paying particular attention to data reduction and background subtraction
Uploaded on: March 1, 2023 -
November 30, 2016 (v1)Publication
We have measured the radiative neutron-capture cross section and the total neutron-induced cross section of one of the most important isotopes for the s process, the 25Mg. The measurements have been carried out at the neutron time-of-flight facilities n_TOF at CERN (Switzerland) and GELINA installed at the EC-JRC-IRMM (Belgium). The cross...
Uploaded on: December 4, 2022 -
November 30, 2016 (v1)Publication
The n_TOF facility operates at CERN with the aim of addressing the request of high accuracy nuclear data for advanced nuclear energy systems as well as for nuclear astrophysics. Thanks to the features of the neutron beam, important results have been obtained on neutron induced fission and capture cross sections of U, Pu and minor actinides....
Uploaded on: December 4, 2022 -
September 7, 2020 (v1)Publication
In the first ten years of operation, the neutron time-of-flight facility n_TOF at CERN has produced a large body of new and accurate data on neutron capture and fission cross sections, relevant to Nuclear Astrophysics and advanced nuclear technologies. In the next phase, with the construction of a second experimental area with a shorted flight...
Uploaded on: March 27, 2023 -
December 1, 2016 (v1)Publication
The study of neutron-induced reactions is of high relevance in a wide variety of fields, ranging from stellar nucleosynthesis and fundamental nuclear physics to applications of nuclear technology. In nuclear energy, high accuracy neutron data are needed for the development of Generation IV fast reactors and accelerator driven systems, these...
Uploaded on: December 4, 2022 -
December 1, 2016 (v1)Publication
The neutron time-of-flight facility n_TOF at CERN, Switzerland, operational since 2001, delivers neutrons using the Proton Synchrotron (PS) 20 GeV/c proton beam impinging on a lead spallation target. The facility combines a very high instantaneous neutron flux, an excellent time of flight resolution due to the distance between the experimental...
Uploaded on: March 27, 2023 -
December 1, 2016 (v1)Publication
The study of the resonant structures in neutron-nucleus cross-sections, and therefore of the compound-nucleus reaction mechanism, requires spectroscopic measurements to determine with high accuracy the energy of the neutron interacting with the material under study. To this purpose, the neutron time-of-flight facility n_TOF has been operating...
Uploaded on: December 4, 2022 -
June 3, 2019 (v1)Publication
The integral measurement of the 12C(n, p)12B reaction was performed at the neutron time-offlight facility n TOF at CERN. The total number of 12B nuclei produced per neutron pulse of the n TOF beam was determined using the activation technique in combination with a time-of-flight technique. The cross section is integrated over the n TOF neutron...
Uploaded on: March 27, 2023 -
April 7, 2021 (v1)Publication
HiSPANoS (HiSPAlis Neutron Source) is the first accelerator-based neutron facility in Spain, installed at the Centro Nacional de Aceleradores (CNA), where different experiments have been performed related to nuclear astrophysics, detector characterization, electronic devices irradiation, imaging, etc. An upgrade of the neutron facility has been...
Uploaded on: December 4, 2022 -
November 9, 2017 (v1)Publication
We report a new measurement of the Li8 half-life using a plastic scintillator and an ultrafast waveform digitizing module. The result, T1/2=(838.40±0.36)ms, improves by a factor of 2.5 the most precise result obtained so far and is furthermore deduced with negligible corrections due to dead time.
Uploaded on: December 5, 2022 -
April 5, 2017 (v1)Publication
We have measured the neutron capture cross sections of the stable magnesium isotopes 24 ,25 ,26Mg in the energy range of interest to the s process using the neutron time-of-flight facility n-TOF at CERN. Capture events from a natural metal sample and from samples enriched in 25Mg and 26Mg were recorded using the total energy method based on C...
Uploaded on: March 1, 2023 -
April 5, 2017 (v1)Publication
The neutron-induced fission cross section of 236U was measured at the neutron Time-of-Flight (n-TOF) facility at CERN relative to the standard 235U(n,f) cross section for neutron energies ranging from above thermal to several MeV. The measurement, covering the full range simultaneously, was performed with a fast ionization chamber, taking...
Uploaded on: December 5, 2022 -
April 4, 2017 (v1)Publication
The integral cross section of the 12C(n,p)12B reaction has been determined for the first time in the neutron energy range from threshold to several GeV at the n-TOF facility at CERN. The measurement relies on the activation technique with the β decay of 12B measured over a period of four half-lives within the same neutron bunch in which the...
Uploaded on: March 27, 2023 -
April 5, 2017 (v1)Publication
The neutron-induced fission cross section of 245Cm was measured at n-TOF in a wide energy range and with high resolution. The energy dependence, measured in a single measurement from 30 meV to 1 MeV neutron energy, has been determined with 5% accuracy relative to the 235U(n,f) cross section. In order to reduce the uncertainty on the absolute...
Uploaded on: March 25, 2023 -
March 2, 2022 (v1)Publication
The 58 Ni( n , γ ) 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 k T = 5 – 100 keV with uncertainties of...
Uploaded on: December 5, 2022