| 1. |
- Domingo-Pardo, C., et al.
(author)
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Compton imaging for enhanced sensitivity (n,gamma) cross section TOF experiments : Status and prospects
- 2023
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In: 15TH INTERNATIONAL CONFERENCE ON NUCLEAR DATA FOR SCIENCE AND TECHNOLOGY, ND2022. - : EDP Sciences.
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Conference paper (peer-reviewed)abstract
- Radiative neutron-capture cross sections are of pivotal importance in many fields such as nucle-osynthesis studies or innovative reactor technologies. A large number of isotopes have been measured with high accuracy, but there are still a large number of relevant isotopes whose cross sections could not be experimentally determined yet, at least with sufficient accuracy and completeness, owing to limitations in detection techniques, sample production methods or in the facilities themselves. In the context of the HYMNS (High-sensitivitY Measurements of key stellar Nucleo-Synthesis reactions) project over the last six years we have developed a novel detection technique aimed at background suppression in radiative neutron-capture time-of-flight measurements. This new technique utilizes a complex detection set-up based on position-sensitive radiation-detectors deployed in a Compton-camera array configuration. The latter enables to implement gamma-ray imaging techniques, which help to disentangle true capture events arising from the sample under study and contaminant background events from the surroundings. A summary on the main developments is given in this contribution together with an update on recent experiments at CERN n_TOF and an outlook on future steps.
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| 2. |
- Dupont, E., et al.
(author)
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Overview of the dissemination of n_TOF experimental data and resonance parameters
- 2023
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In: 15TH INTERNATIONAL CONFERENCE ON NUCLEAR DATA FOR SCIENCE AND TECHNOLOGY, ND2022. - : EDP Sciences.
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Conference paper (peer-reviewed)abstract
- The n_TOF neutron time-of-flight facility at CERN is used for nuclear data measurements. The n_TOF Collaboration works closely with the Nuclear Reaction Data Centres (NRDC) network to disseminate the experimental data through the international EXFOR library. In addition, the Collaboration helps integrate the results in the evaluated library projects. The present contribution describes the dissemination status of n_TOF results, their impact on evaluated libraries and ongoing efforts to provide n_TOF resonance parameters in ENDF-6 format for further use by evaluation projects.
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| 3. |
- Mastromarco, M., et al.
(author)
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Measurement of the Gd-160(n, gamma) cross section at n_TOF and its medical implications
- 2023
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In: 15TH INTERNATIONAL CONFERENCE ON NUCLEAR DATA FOR SCIENCE AND TECHNOLOGY, ND2022. - : EDP Sciences.
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Conference paper (peer-reviewed)abstract
- Neutron-capture reactions on gadolinium isotopes play an important role in several fields of physics, in particular in nuclear Astrophysics for the understanding of the nucleosynthesis of heavy elements (beyond iron) in stars via the s- and r-processes [1] and in nuclear technology. Another important application of gadolinium is linked to the production of terbium, that offers a set of clinically interesting isotopes for theranostics, characterized by complementary physical decay characteristics. In particular, the low -energy beta(-) emitter terbium-161 is very similar to lutetium-177 in terms of half-life (6.89 d), beta(-) - energy and chemical properties. Being a significant emitter of conversion/Auger electrons, greater therapeutic effect can therefore be expected in comparison to Lu-177 [2, 3]. For this reason, in the last decade, the study of the neutron capture reaction Gd-160(n,,gamma)(161) Gd and the subsequent beta(-) - decay in terbium-161 is getting particular attention. As the nuclear data on the Gd-160 neutron capture reaction are quite scarce and inconsistent, a new measurement of the capture cross section of Gd-160 at the CERN neutron Time -Of-Flight facilty was performed in order to provide high resolution, high -accuracy data on this important reaction, in the energy range from thermal to hundreds of keV. In this contribution, the preliminary results of the n_TOF measurement are presented.
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| 4. |
- Lerendegui-Marco, J., et al.
(author)
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New perspectives for neutron capture measurements in the upgraded CERN-n_TOF Facility
- 2023
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In: 15th International Conference on Nuclear Data for Science and Technology, ND2022. - : EDP Sciences.
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Conference paper (peer-reviewed)abstract
- The n_TOF facility has just undergone in 2021 a major upgrade with the installation of its third generation spallation target that has been designed to optimize the performance of the two n_TOF time-of-flight lines. This contribution describes the key features and limitations for capture measurements in the two beam lines prior to the target upgrade and presents first results of (n,gamma) measurements carried out as part of the commissioning of the upgraded facility. In particular, the energy resolution, a key factor for both increasing the signal-to background ratio and obtaining accurate resonance parameters, has been clearly improved for the 20 m long vertical beam-line with the new target design while keeping the remarkably high resolution of the long beamline n_TOF-EAR1. The improvements in the n_TOF neutron beam-lines need to be accompanied by improvements in the instrumentation. A review is given on recent detector R&D projects aimed at tackling the existing challenges and further improving the capabilities of this facility.
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| 5. |
- Mucciola, R., et al.
(author)
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Neutron capture and total cross-section measurements on Mo-94'95'96 at n_TOF and GELINA
- 2023
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In: 15th International Conference on Nuclear Data for Science and Technology, ND2022. - : EDP Sciences.
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Conference paper (peer-reviewed)abstract
- Capture and total cross section measurements for 94'95'96 MO have been performed at the neutron time -of-flight facilities, n_TOF at CERN and GELINA at JRC-Geel. The measurements were performed using isotopically enriched samples with an enrichment above 95% for each of the (94'95'96)M0 isotopes. The capture measurements were performed at n_TOF using C6D6 detectors and a new sTED detector. The transmission measurements were performed at a 10 m station of GELINA using a Li-6 glass neutron detector. Preliminary results of these measurements are presented.
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| 6. |
- Alcayne, V., et al.
(author)
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A segmented total energy detector (sTED) for (n, gamma) cross section measurements at n_TOF EAR2
- 2023
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In: 15TH INTERNATIONAL CONFERENCE ON NUCLEAR DATA FOR SCIENCE AND TECHNOLOGY, ND2022. - : EDP Sciences.
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Conference paper (peer-reviewed)abstract
- The neutron time-of-flight facility n_TOF is characterised by its high instantaneous neutron intensity, high resolution and broad neutron energy spectra, specially conceived for neutron-induced reaction cross section measurements. Two Time-Of-Flight (TOR) experimental areas are available at the facility: experimental area 1 (EAR1), located at the end of the 185 m horizontal flight path from the spallation target, and experimental area 2 (EAR2), placed at 20 m from the target in the vertical direction. The neutron fluence in EAR2 is similar to 300 times more intense than in EARL in the relevant time-of-flight window. EAR2 was designed to carry out challenging cross-section measurements with low mass samples (approximately 1 mg), reactions with small cross-sections or/and highly radioactive samples. The high instantaneous fluence of EAR2 results in high counting rates that challenge the existing capture systems. Therefore, the sTED detector has been designed to mitigate these effects. In 2021, a dedicated campaign was done validating the performance of the detector up to at least 300 keV neutron energy. After this campaign, the detector has been used to perform various capture cross section measurements at n_TOF EAR2.
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| 7. |
- Garcia-Infantes, F., et al.
(author)
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First high resolution measurement of neutron capture resonances in Yb-176 at the n_TOF CERN facility.
- 2023
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In: 15TH INTERNATIONAL CONFERENCE ON NUCLEAR DATA FOR SCIENCE AND TECHNOLOGY, ND2022. - : EDP Sciences.
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Conference paper (peer-reviewed)abstract
- Several international agencies recommend the study of new routes and new facilities for producing radioisotopes with application to nuclear medicine. Lu-177 is a versatile radioisotope used for therapy and diagnosis (theranostics) of cancer with good success in neuroendocrine tumours that is being studied to be applied to a wider range of tumours. Lu-177 is produced in few nuclear reactors mainly by the neutron capture on Lu-176. However, it could be produced at high -intensity accelerator-based neutron facilities. The energy of the neutrons in accelerator-based neutron facilities is higher than in thermal reactors. Thus, experimental data on the Yb-176(n,(sic)) cross-section in the eV and keV region are mandatory to calculate accurately the production of Yb-177, which beta decays to 177Lu. At present, there are not experimental data available from thermal to 3 keV of the Yb-176(n,(sic)) cross-section. In addition, there is no data in the resolved resonance region (RRR). This contribution shows the first results of the Yb-176 capture measurement performed at the n_TOF facility at CERN.
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| 8. |
- Pavon-Rodriguez, J. A., et al.
(author)
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Characterisation of the n_TOF 20 m beam line at CERN with the new spallation target
- 2023
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In: 15TH INTERNATIONAL CONFERENCE ON NUCLEAR DATA FOR SCIENCE AND TECHNOLOGY, ND2022. - : EDP Sciences.
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Conference paper (peer-reviewed)abstract
- The n_TOF facility hosts CERN's pulsed neutron source, comprising two beam lines of different flight paths and one activation station. It is based on a proton beam delivered by the PS accelerator impinging on a lead spallation target. During Long Shutdown 2 (LS2) at CERN (2019-2021), a major upgrade of the spallation target was carried out in order to optimize the performances of the neutron beam. Therefore, the characteristics of n_TOF two experimental areas were investigated in detail. In this work, the focus is on the second experimental area (EAR2), located 20 m above the spallation target. Preliminary results of the neutron energy distribution and beam line energy resolution are presented, compared to previous experimental campaigns and Monte Carlo simulations with the FLUKA code. Moreover, preliminary results of the spatial beam profile measurements are shown.
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| 9. |
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| 10. |
- Stamati, M. E., et al.
(author)
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The n_TOF NEAR Station Commissioning and first physics case
- 2023
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In: 15TH INTERNATIONAL CONFERENCE ON NUCLEAR DATA FOR SCIENCE AND TECHNOLOGY, ND2022. - : EDP Sciences.
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Conference paper (peer-reviewed)abstract
- The NEAR Station is a new experimental area developed at the n_TOF Facility at CERN. The activation station of NEAR underwent a characterization of the beam following the installation of the new n_TOF Spallation Target. The commissioning of the neutron beam comprises a set of simulations made with the FLUKA code and experimental verification. The experimental determination of the neutron spectrum was made using activation techniques with three separate set-ups. Two set-ups were based on the Multi-foil Activation technique (MAM-1 and MAM-2), and the third set-up relied on the process of neutron moderation and activation of a single material (ANTILoPE). The three set-ups are presented. Also the present plans and future perspectives of the activation station of NEAR are discussed.
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