scholarly journals From nuclear astrophysics to fundamental nuclear physics: challenging experimental approaches at n_TOF (CERN)

2021 ◽  
Vol 252 ◽  
pp. 05002
Author(s):  
Agatino Musumarra
Keyword(s):  
Nuclear Physics ◽  
Scattering Length ◽  
Nuclear Astrophysics ◽  
Neutron Cross Section ◽  
Neutron Spallation Source ◽  
Spallation Source ◽  
Body Kinematic ◽  
Experimental Approaches ◽  
Leading Neutron ◽  
Three Body

The n_TOF installation at CERN is one of the leading neutron facilities worldwide undergoing a major update of the neutron spallation source. The update will provide improved n-TOF resolution in the experimental areas and the possibility to perform neutron cross section measurements at very high neutron flux (NEAR-Station). The renewed capabilities of the facility must be supported by smart and non-conventional experimental approaches. In this framework two examples will be reported. The first one concerns the measurement of a key reaction channel involved in Primordial Nucleosynthesis: the 7Be(n, α), by using a radioactive 7Be target. The second one provides a state-of-the-art scenario for the n-n scattering length measurement. This will be performed by neutron-deuteron (n-d) breakup three-body reaction. In this case, the envisaged experimental setup will provide a complete three-body kinematic reconstruction. By these important physics cases we are crossing the technological frontiers for charged particle and neutron detection.

scholarly journals Nuclear Physics Research at ELI-NP

2018 ◽  
Vol 178 ◽  
pp. 01002
Author(s):  
N.V. Zamfir
Keyword(s):  
Laser Beam ◽  
Nuclear Physics ◽  
Gamma Ray ◽  
Nuclear Astrophysics ◽  
Resonance Fluorescence ◽  
Particle Beams ◽  
Experimental Approaches ◽  
Under Construction ◽  
New Research ◽  
Intense Radiation

The new research facility Extreme Light Infrastructure – Nuclear Physics (ELI-NP) is under construction in Romania, on the Magurele Physics campus. Valued more than 300 Meuros the center will be operational in 2019. The research center will use a high brilliance Gamma Beam and a High-power Laser beam, with unprecedented characteristics worldwide, to investigate the interaction of very intense radiation with matter with specific focus on nuclear phenomena and their applications. The energetic particle beams and radiation produced by the 2x10 PW laser beam interacting with matter will be studied. The precisely tunable energy and excellent bandwidth of the gamma-ray beam will allow for new experimental approaches regarding nuclear astrophysics, nuclear resonance fluorescence, and applications. The experimental equipment is presented, together with the main directions of the research envisioned with special emphasizes on nuclear physics studies.

scholarly journals Design of the third-generation neutron spallation target for the CERN’s n_TOF facility

2020 ◽  
Vol 22 (2-3) ◽  
pp. 221-231
Author(s):  
Raffaele Esposito ◽  
Marco Calviani
Keyword(s):  
Particle Physics ◽  
Cooling Water ◽  
Nuclear Astrophysics ◽  
Lead Target ◽  
Third Generation ◽  
Spallation Target ◽  
Neutron Spallation Source ◽  
European Laboratory ◽  
Neutron Time ◽  
Spallation Source

The neutron Time-Of-Flight (n_TOF) facility at the European Laboratory for Particle Physics (CERN) is a pulsed white-spectrum neutron spallation source producing neutrons for two experimental areas: EAR1, located 185 m downstream of the spallation target, and EAR2, located 20 m above the target. The facility is based on a lead target impacted by a high-intensity 20 GeV/c proton beam. It is designed to study neutron-nucleus interactions for neutron kinetic energies from a few meV to several GeV, with applications in nuclear astrophysics, nuclear technology, and medical research. The facility is undergoing a major upgrade in 2019–2020, which will include the installation of the new third-generation target. The second-generation target consists in a water-cooled lead cylinder, while the new target will be cooled by nitrogen to avoid erosion-corrosion phenomena and contamination of the cooling water with radioactive lead spallation products. The new design will be optimized also for the vertical flight path. The operation of the new spallation target will start in 2021. This paper presents an overview on the evolution of the design and on the related R&D activities (including beam irradiation tests) carried out to ensure the best performance for both experimental areas and avoid the contamination issues of the previous targets.

Many-body Green functions in nuclear physics

2017 ◽  
Vol 26 (01n02) ◽  
pp. 1740025 ◽  
Author(s):  
J. Speth ◽  
N. Lyutorovich
Keyword(s):  
Nuclear Physics ◽  
Green Functions ◽  
Many Body ◽  
General Applicability ◽  
Pair Correlations ◽  
Self Consistent ◽  
The Many ◽  
The One ◽  
General Relations ◽  
Three Body

Many-body Green functions are a very efficient formulation of the many-body problem. We review the application of this method to nuclear physics problems. The formulas which can be derived are of general applicability, e.g., in self-consistent as well as in nonself-consistent calculations. With the help of the Landau renormalization, one obtains relations without any approximations. This allows to apply conservation laws which lead to important general relations. We investigate the one-body and two-body Green functions as well as the three-body Green function and discuss their connection to nuclear observables. The generalization to systems with pair correlations are also presented. Numerical examples are compared with experimental data.

Mechanical Spectroscopy Investigation of Liquid Pb-Bi Alloys

2012 ◽  
Vol 184 ◽  
pp. 434-439 ◽  
Author(s):  
Roberto Montanari ◽  
Alessandra Varone
Keyword(s):  
Distribution Functions ◽  
X Ray Diffraction ◽  
Mechanical Spectroscopy ◽  
X Ray ◽  
Neutron Spallation Source ◽  
Driven System ◽  
Spallation Source ◽  
Accelerator Driven System ◽  
The Mean ◽  
Diffraction Patterns

Liquid Pb–Bi eutectic alloy has been selected as coolant and neutron spallation source for the development of MYRRHA, an accelerator driven system. The alloy has been characterized in liquid state from melting (125 °C) to 650 °C by mechanical spectroscopy. Experiments have been carried out using hollow reeds of austenitic stainless steel filled with the Pb-Bi alloy and sealed at the extremities. From 350 °C to 520 °C modulus shows a remarkable drop accompanied by a broad internal friction maximum. In the same temperature range radial distribution functions, determined from X-ray diffraction patterns, evidenced variations of the mean distance between the 1st nearest neighbour atoms. The anelastic phenomena have been attributed to a structural re-arrangement of liquid metal. For comparison, other alloys of the Pb-Bi system with hypo-eutectic composition have been investigated.

BOSE-EINSTEIN CONDENSATION OF ATOMS WITH ATTRACTIVE INTERACTION

1999 ◽  
Vol 13 (05n06) ◽  
pp. 625-631 ◽  
Author(s):  
N. AKHMEDIEV ◽  
M. P. DAS ◽  
A. V. VAGOV
Keyword(s):  
Statistical Physics ◽  
Scattering Length ◽  
Stationary Solutions ◽  
Attractive Potential ◽  
Einstein Condensation ◽  
Pitaevskii Equation ◽  
Bose Einstein Condensation ◽  
Three Body ◽  
Negative Scattering Length ◽  
Bose Einstein

We suggest that crucial effect on Bose-Einstein condensation in systems with attractive potential is three-body interaction. We investigate stationary solutions of the Gross-Pitaevskii equation with negative scattering length and a higher-order stabilising term in presence of an external parabolic potential. Stability properties of the condensate are similar to those for thermodynamic systems in statistical physics which have first order phase transitions. We have shown that there are three possible type of stationary solutions corresponding to stable, metastable and unstable phases. Results are discussed in relation to recently observed 7 Li condensate.

scholarly journals Status and perspectives of the neutron time-of-flight facility n_TOF at CERN

2020 ◽  
Vol 239 ◽  
pp. 17001
Author(s):  
E. Chiaveri ◽  
O. Aberle ◽  
V. Alcayne ◽  
S. Amaducci ◽  
J. Andrzejewski ◽  
...  
Keyword(s):  
Time Of Flight ◽  
Nuclear Astrophysics ◽  
Neutron Cross Section ◽  
Medical Applications ◽  
Spallation Target ◽  
The Future ◽  
Wide Energy ◽  
Neutron Time ◽  
Instantaneous Neutron ◽  
Open Issues

Since the start of its operation in 2001, based on an idea of Prof. Carlo Rubbia [1], the neutron time of-flight facility of CERN, n_TOF, has become one of the most forefront neutron facilities in the world for wide-energy spectrum neutron cross section measurements. Thanks to the combination of excellent neutron energy resolution and high instantaneous neutron flux available in the two experimental areas, the second of which has been constructed in 2014, n_TOF is providing a wealth of new data on neutron-induced reactions of interest for nuclear astrophysics, advanced nuclear technologies and medical applications. The unique features of the facility will continue to be exploited in the future, to perform challenging new measurements addressing the still open issues and long-standing quests in the field of neutron physics. In this document the main characteristics of the n_TOF facility and their relevance for neutron studies in the different areas of research will be outlined, addressing the possible future contribution of n_TOF in the fields of nuclear astrophysics, nuclear technologies and medical applications. In addition, the future perspectives of the facility will be described including the upgrade of the spallation target, the setup of an imaging installation and the construction of a new irradiation area.

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