Choose timezone
Your profile timezone:
ISOLDE Seminar
The n_TOF project: neutron cross-sections for Astrophysics and Nuclear Technologies
by
→
Europe/Zurich
26-1-22 (CERN)
26-1-22
CERN
Description
Neutron cross-sections are of primary importance for basic and applied Nuclear Physics. In particular, they are essential in Nuclear Astrophysics for understanding the production of heavy elements in the Universe (A>60), which occurs during the various phases of stellar evolution mostly through slow and rapid neutron capture processes. While the main features of stellar nucleosynthesis are now well understood, a more refined modelling of the elemental abundances, and of the chemical evolution of the Universe, requires accurate new data on various isotopes, either rare, radioactive, or with low cross-sections, on which scarce and discrepant data exist to date.
New and accurate neutron data are also required in the field of Nuclear Technology, for improving the safety and efficiency of current nuclear reactors and, especially, for the development of advanced systems, such as sub-critical Accelerator Driven Systems and Generation IV fast reactors, that would overcome major drawbacks of present technology, in particular the inefficient use of uranium resources and the production of long-lived nuclear waste. The design and operation of these new systems require high-precision cross-section data on a long list of isotopes, mostly radioactive, in particular plutonium, minor actinides, fission fragments and structural materials.
Based on an idea of Rubbia, the spallation neutron source n_TOF was built ten years ago at CERN, to address some of the pressing needs of accurate new data on neutron cross-sections. The facility, based on the spallation of 20 GeV/c protons on a water-cooled Pb targer, is characterized by the combination of high neutron flux, excellent energy resolution, low backgrounds and very low duty cycle, resulting in the most luminous neutron source world-wide. All these features make n_TOF a unique installation, in particular for the measurement of radioactive isotopes. The excellent performance of the facility is complemented by the use of the most advanced detection and data acquisition techniques, providing the ideal environment for neutron time-of-flight experiments covering the full energy range of astrophysical and nuclear technology interest.
After a brief description of the n_TOF facility and of the experimental setups used for capture and fission measurements, a review of the results obtained in the first measurement campaign at CERN will be presented in this seminar. The features of the n_TOF facility have recently been further improved by refurbishing the spallation target, and by modifying the experimental area to allow handling of radioactive samples. Following these changes, a new, rich experimental campaign has just started. An overview of the future measurements proposed by the n_TOF Collaboration for the next few years will be presented.
