scholarly journals Underground Nuclear Astrophysics: pushing direct measurements toward the Gamow window

2020 ◽  
Vol 227 ◽  
pp. 01015
Author(s):  
Paolo Prati
Keyword(s):  
Nuclear Reactions ◽  
Nuclear Astrophysics ◽  
Cosmic Ray ◽  
Reaction Rates ◽  
Carbon Ions ◽  
Ongoing Research ◽  
Ion Accelerator ◽  
Direct Measurements ◽  
Low Energies ◽  
Deep Underground

The aim of experimental nuclear astrophysics is to provide information on the nuclear processes involved in astrophysical scenarios at the relevant energy range. However, the measurement of the cross section of nuclear reactions at low energies present formidable difficulties due to the very low reaction rates often overwhelmed by the background. Several approaches have been proposed and exploited to overcome such severe obstacles: in such frame, the idea to install a low energy - high intensity ion accelerator deep underground, to gain high luminosity while reducing the cosmic ray background, brought more than 25 years ago, to the pilot LUNA experiment. LUNA stands for Laboratory for Underground Nuclear Astrophysics: in the cave under the Gran Sasso mountain (in Italy) first a 50 kV and then a 400 kV single-ended accelerator for protons and alphas were deployed and produced plenty of data mainly on reactions of the H-burning phase in stars. Recently, similar facilities have been installed and/or proposed in other underground laboratories in US and China. LUNA as well is going to make a big step forward, with a new machine in the MV range which will be able to provide intense beams of protons, alphas and carbon ions. The rationale of underground nuclear astrophysics will be presented together with the last updates on the ongoing research programs.

scholarly journals Nuclear Astrophysics Deep Underground

2018 ◽  
Vol 46 ◽  
pp. 1860003 ◽  
Author(s):  
Rosanna Depalo
Keyword(s):  
Cross Sections ◽  
Nuclear Reactions ◽  
Nuclear Astrophysics ◽  
Cosmic Ray ◽  
Big Bang ◽  
Big Bang Nucleosynthesis ◽  
Present Contribution ◽  
Hydrogen Burning ◽  
The Earth ◽  
Deep Underground

Cross sections of nuclear reactions relevant for astrophysics are crucial ingredients to understand the energy generation inside stars and the synthesis of the elements. At astrophysical energies, nuclear cross sections are often too small to be measured in laboratories on the Earth surface, where the signal would be overwhelmed by the cosmic-ray induced background. LUNA is a unique Nuclear Astrophysics experiment located at Gran Sasso National Laboratories. The extremely low background achieved at LUNA allows to measure nuclear cross sections directly at the energies of astrophysical interest. Over the years, many crucial reactions involved in stellar hydrogen burning as well as Big Bang nucleosynthesis have been measured at LUNA. The present contribution provides an overview on underground Nuclear Astrophysics as well as the latest results and future perspectives of the LUNA experiment.

scholarly journals Global predictions for astrophysics applications

2020 ◽  
Vol 13 ◽  
pp. 18
Author(s):  
P. Demetriou
Keyword(s):  
Nuclear Reaction ◽  
Cross Sections ◽  
Nuclear Reactions ◽  
Nuclear Astrophysics ◽  
Reaction Network ◽  
Reaction Rates ◽  
Reaction Cross ◽  
Hartree Fock ◽  
Microscopic Models ◽  
The Stability

Nuclear reaction rates play a crucial role in nuclear astrophysics. In the last decades there has been an enormous effort to measure reaction cross sections and extensive experimental databases have been compiled as a result. In spite of these efforts, most nuclear reaction network calculations still have to rely on theoretical predic- tions of experimentally unknown rates. In particular, in astrophysics applications such as the s-, r- and p-process nucleosynthesis involving a large number of nuclei and nuclear reactions (thousands). Moreover, most of the ingredients of the cal- culations of reaction rates have to be extrapolated to energy and/or mass regions that cannot be explored experimentally. For this reason it is important to develop global microscopic or semi-microscopic models of nuclear properties that give an accurate description of existing data and are reliable for predictions far away from the stability line. The need for more microscopic input parameters has led to new devel- opments within the Hartree-Fock-Bogoliubov method, some of which are presented in this paper.

Underground nuclear astrophysics experiment JUNA in China

2019 ◽  
Vol 15 (S350) ◽  
pp. 313-320
Author(s):  
LIU WeiPing ◽  
LI ZhiHong ◽  
HE JiangJun ◽  
TANG XiaoDong ◽  
LIAN Gang ◽  
...  
Keyword(s):  
Stellar Evolution ◽  
Nuclear Reactions ◽  
Nuclear Astrophysics ◽  
High Current ◽  
Low Background ◽  
Direct Measurements ◽  
Ecr Source

AbstractUnderground Nuclear Astrophysics in China (JUNA) will take the advantage of the ultra-low background in Jinping underground lab. High current accelerator with an ECR source and detectors were commissioned. JUNA plans to study directly a number of nuclear reactions important to hydrostatic stellar evolution at their relevant stellar energies. At the first period, JUNA aims at the direct measurements of 25Mg(p,γ)26 Al, 19F(p,α) 16 O, 13C(α, n) 16O and 12C(α,γ) 16O near the Gamow window. The current progress of JUNA will be given.

Calculation of fusion rates at extremely low energies in laser plasmas

2010 ◽  
Vol 6 (S274) ◽  
pp. 44-47 ◽  
Author(s):  
D. Mascali ◽  
N. Gambino ◽  
S. Tudisco ◽  
A. Anzalone ◽  
A. Bonanno ◽  
...  
Keyword(s):  
Nuclear Reactions ◽  
Fusion Reaction ◽  
Reaction Rates ◽  
Debye Screening ◽  
Fusion Reactions ◽  
Plasma Dynamics ◽  
Laser Plasmas ◽  
Low Energies ◽  
Screening Factor ◽  
The One

AbstractAt temperatures and densities that are typical of plasmas produced by lasers pulses interacting with solid targets, at power intensities I > 1012W/cm2, the classical Debye screening factor in nuclear reactions becomes comparable with the one of the solar core. Preliminary calculations about the total number of fusion reactions have been performed following an hydrodynamical approach for the description of the plasma dynamics. This approach is propaedeutic for future measurements of D-D fusion reaction rates.

scholarly journals NUCLEAR MEAN-FIELD DESCRIPTION OF PROTON ELASTIC SCATTERING BY 12,13 C AT LOW ENERGIES

2020 ◽  
Vol 31 (1) ◽  
Author(s):  
Huan Nhut Phan
Keyword(s):  
Elastic Scattering ◽  
Cross Sections ◽  
Nuclear Reactions ◽  
Mean Field ◽  
Nuclear Astrophysics ◽  
Nucleon Nucleon ◽  
Light Nuclei ◽  
Intermediate Energies ◽  
Proton Elastic Scattering ◽  
Low Energies

Nuclear reactions of proton by light nuclei at low energies play a key role in the study ofnucleosynthesis which is of interest in nuclear astrophysics. The most fundamental process whichis very necessary is the elastic scattering. In this work, we construct a microscopic proton-nucleuspotential in order to describe the differential cross-sections over scattering angles of the protonelastic scattering by 12C and 13C in the range of available energies 14 - 22 MeV. The microscopicoptical potential is based on the folding model using the effective nucleon-nucleon interactionCDM3Yn. The results show the promising use of the CDM3Yn interactions at low and very lowenergies, which were originally used for nuclear reactions at intermediate energies. This could bethe premise for the study of nuclear reactions using CDM3Yn interaction in astrophysics at lowenergies.

Origin and status of LUNA at Gran Sasso

2014 ◽  
Vol 29 (34) ◽  
pp. 1430038
Author(s):  
Carlo Broggini ◽  
Keyword(s):  
Nuclear Physics ◽  
Nuclear Reactions ◽  
Chemical Elements ◽  
Nuclear Astrophysics ◽  
Hydrogen Burning ◽  
Proton Proton ◽  
Oxygen Cycle ◽  
Comprehensive Picture ◽  
Deep Underground ◽  
The Universe

The ultimate goal of nuclear astrophysics, the union of nuclear physics and astronomy, is to provide a comprehensive picture of the nuclear reactions which power the stars and, in doing so, synthesize the chemical elements. Deep underground in the Gran Sasso Laboratory the key reactions of the proton–proton chain and of the carbon–nitrogen–oxygen cycle have been studied down to the energies of astrophysical interest. The main results obtained in the past 20 years are reviewed and their influence on our understanding of the properties of the neutrino, the Sun, and the Universe itself is discussed. Finally, future developments of underground nuclear astrophysics beyond the study of hydrogen burning are outlined.

scholarly journals Transfer Reactions As a Tool in Nuclear Astrophysics

2021 ◽  
Vol 8 ◽  
Author(s):  
Faïrouz Hammache ◽  
Nicolas de Séréville
Keyword(s):  
Cross Sections ◽  
Transfer Reaction ◽  
Nuclear Reactions ◽  
Experimental Studies ◽  
Nuclear Astrophysics ◽  
Spectroscopic Properties ◽  
Reaction Rates ◽  
Theoretical Concept ◽  
Reaction Method ◽  
Basic Features

Nuclear reaction rates are one of the most important ingredients in describing how stars evolve. The study of the nuclear reactions involved in different astrophysical sites is thus mandatory to address most questions in nuclear astrophysics. Direct measurements of the cross-sections at stellar energies are very challenging–if at all possible. This is essentially due to the very low cross-sections of the reactions of interest (especially when it involves charged particles), and/or to the radioactive nature of many key nuclei. In order to overcome these difficulties, various indirect methods such as the transfer reaction method at energies above or near the Coulomb barrier are used to measure the spectroscopic properties of the involved compound nucleus that are needed to calculate cross-sections or reaction rates of astrophysical interest. In this review, the basic features of the transfer reaction method and the theoretical concept behind are first discussed, then the method is illustrated with recent performed experimental studies of key reactions in nuclear astrophysics.

scholarly journals Underground Nuclear Astrophysics: Present and future of the LUNA experiment

2019 ◽  
Vol 209 ◽  
pp. 01043
Author(s):  
Carlo Gustavino
Keyword(s):  
Nuclear Astrophysics ◽  
Reaction Rates ◽  
Big Bang ◽  
Scientific Program ◽  
Thermonuclear Reaction ◽  
Big Bang Nucleosynthesis ◽  
Celestial Bodies ◽  
Deep Underground ◽  
The Big Bang ◽  
Nuclear Processes

The evolution of celestial bodies is regulated by gravitation and thermonuclear reaction rates, while the Big Bang nucleosynthesis is the result of nuclear processes in a rapidly expanding Universe. The LUNA Collaboration has shown that, by exploiting the ultra low background achievable deep underground, it is possible to study the relevant nuclear processes down to the nucleosynthesis energy inside stars and during the first minutes of Universe. In this paper the main results of LUNA are overviewed, as well as the scientific program the forthcoming 3.5 MV underground accelerator.

scholarly journals THE PATH TO IMPROVED REACTION RATES FOR ASTROPHYSICS

2011 ◽  
Vol 20 (05) ◽  
pp. 1071-1169 ◽  
Author(s):  
THOMAS RAUSCHER
Keyword(s):  
Strong Interaction ◽  
Nuclear Reactions ◽  
Experimental Studies ◽  
Nuclear Astrophysics ◽  
Reaction Rates ◽  
Light Ions ◽  
Α Particles

This review focuses on nuclear reactions in astrophysics and, more specifically, on reactions with light ions (nucleons and α particles) proceeding via the strong interaction. It is intended to present the basic definitions essential for studies in nuclear astrophysics, to point out the differences between nuclear reactions taking place in stars and in a terrestrial laboratory, and to illustrate some of the challenges to be faced in theoretical and experimental studies of those reactions. The discussion revolves around the relevant quantities for astrophysics, which are the astrophysical reaction rates. The sensitivity of the reaction rates to the uncertainties in the prediction of various nuclear properties is explored and some guidelines for experimentalists are also provided.

scholarly journals The Study of Key Reactions Shaping the Post-Main Sequence Evolution of Massive Stars in Underground Facilities

2021 ◽  
Vol 7 ◽  
Author(s):  
F. Ferraro ◽  
G. F. Ciani ◽  
A. Boeltzig ◽  
F. Cavanna ◽  
S. Zavatarelli
Keyword(s):  
Cross Sections ◽  
Main Sequence ◽  
Nuclear Reactions ◽  
Nuclear Astrophysics ◽  
Sequence Evolution ◽  
Present Contribution ◽  
Hydrogen Burning ◽  
Ion Accelerator ◽  
Direct Cross ◽  
Carbon Burning

The chemical evolution of the Universe and several phases of stellar life are regulated by minute nuclear reactions. The key point for each of these reactions is the value of cross-sections at the energies at which they take place in stellar environments. Direct cross-section measurements are mainly hampered by the very low counting rate and by cosmic background; nevertheless, they have become possible by combining the best experimental techniques with the cosmic silence of an underground laboratory. In the nineties, the LUNA (Laboratory for Underground Nuclear Astrophysics) collaboration opened the era of underground nuclear astrophysics, installing first a homemade 50 kV and, later on, a second 400 kV accelerator under the Gran Sasso mountain in Italy: in 25 years of experimental activity, important reactions responsible for hydrogen burning could have been studied down to the relevant energies thanks to the high current proton and helium beams provided by the machines. The interest in the next and warmer stages of star evolution (i.e., post-main sequence and helium and carbon burning) drove a new project based on an ion accelerator in the MV range called LUNA-MV, able to deliver proton, helium, and carbon beams. The present contribution is aimed to discuss the state of the art for some selected key processes of post-main sequence stellar phases: 12C(α,γ)16O and 12C+12C are fundamental for helium and carbon burning phases, and 13C(α,n)16O and 22Ne(α,n)25Mg are relevant to the synthesis of heavy elements in AGB stars. The perspectives opened by an underground MV facility will be highlighted.

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