scholarly journals Underground Measurement of 6Li(p,γ)7Be and 6Li(p,3He)4He Performed at LUNA

2020 ◽  
Vol 1643 (1) ◽  
pp. 012046
Author(s):  
T Chillery
Keyword(s):  
Composition Studies ◽  
Nuclear Astrophysics ◽  
Big Bang ◽  
Abundance Ratio ◽  
Low Energy ◽  
Big Bang Nucleosynthesis ◽  
Target Composition ◽  
S Factor ◽  
Background Measurement ◽  
Proton Induced Reactions

Abstract Proton-induced reactions on 6Li play an important role in nuclear astrophysics studies in relation to primordial lithium abundances. Whilst big bang nucleosynthesis theory excludes the existence of primordial 6Li, the 6Li/7Li abundance ratio observed in pre-main sequence stars is ≃ 0.5. The 6Li(p,3He)4He and 6Li(p,γ)7Be reactions are the main processes that contribute to 6Li destruction in stars. Both reactions were recently studied at LUNA via proton bombardment of 6Li-enriched targets, with complementary target composition studies performed at HZDR. Improvements on the precision of the low-energy S-factor values are expected from this study. Notably, the low-background measurement at LUNA will assist the search for a recently claimed 6Li(p,γ)7Be low energy resonance at E r ≃ 195 keV. I present the LUNA experimental setup and preliminary results of the ongoing analysis.

scholarly journals Proton-Induced Reactions of Astrophysical Interest

2018 ◽  
Vol 184 ◽  
pp. 02001
Author(s):  
Thomas Chillery
Keyword(s):  
Cross Sections ◽  
Main Sequence ◽  
Nuclear Astrophysics ◽  
Big Bang ◽  
High Accuracy ◽  
Low Energy ◽  
Current Status ◽  
Main Sequence Stars ◽  
Big Bang Nucleosynthesis ◽  
Proton Induced Reactions

A discrepancy exists between the 6Li abundances predicted from big bang nucleosynthesis models and those measured in pre-main sequence stars. To further constrain the predicted abundances of 6Li in these stars, high accuracy measurements are required of reactions destroying 6Li. Namely 6Li(p,γ)7Be and 6Li(p,α) 3He. These have recently been studied at the Laboratory for Underground Nuclear Astrophysics (LUNA) to measure their low energy cross sections. I present both the campaign’s experimental setup and current status of the data analysis.

scholarly journals THE 2H(α, γ)6LI REACTION AT LUNA AND BIG BANG NUCLEOSYNTHETIS

2013 ◽  
Vol 53 (A) ◽  
pp. 534-537 ◽  
Author(s):  
Carlo Gustavino
Keyword(s):  
Cross Section ◽  
Preliminary Data ◽  
Big Bang ◽  
Low Energy ◽  
Big Bang Nucleosynthesis ◽  
Lithium Abundance ◽  
Halo Stars ◽  
First Time ◽  
Standard Production ◽  
Production Channel

The <sup>2</sup>H(α, γ)<sup>6</sup>Li reaction is the leading process for the production of <sup>6</sup>Li in standard Big Bang Nucleosynthesis. Recent observations of lithium abundance in metal-poor halo stars suggest that there might be a 6Li plateau, similar to the well-known Spite plateau of <sup>7</sup>Li. This calls for a re-investigation of the standard production channel for <sup>6</sup>Li. As the <sup>2</sup>H(α, γ)<sup>6</sup>Li cross section drops steeply at low energy, it has never before been studied directly at Big Bang energies. For the first time the reaction has been studied directly at Big Bang energies at the LUNA accelerator. The preliminary data and their implications for Big Bang nucleosynthesis and the purported <sup>6</sup>Li problem will be shown.

scholarly journals 3He(α,γ)7Be and 3H(α,γ)7Li reaction rates and implication for Big Bang nucleosynthesis in the potential model

2019 ◽  
Vol 49 ◽  
pp. 1960014 ◽  
Author(s):  
S. A. Turakulov ◽  
E. M. Tursunov
Keyword(s):  
Potential Model ◽  
Reaction Rates ◽  
Big Bang ◽  
Abundance Ratio ◽  
Recent Measurement ◽  
Big Bang Nucleosynthesis ◽  
Body Potential ◽  
Text Element ◽  
Good Agreement

The reaction rates of the direct astrophysical capture processes [Formula: see text] and [Formula: see text], as well as the abundance of the [Formula: see text] element are estimated in the framework of a two-body potential model. The estimated [Formula: see text] abundance ratio of [Formula: see text] is in a very good agreement with the recent measurement [Formula: see text] of the LUNA collaboration.

scholarly journals Low-energy photodisintegration of the deuteron and Big-Bang nucleosynthesis

2003 ◽  
Vol 574 (1-2) ◽  
pp. 8-13 ◽  
Author(s):  
W Tornow ◽  
N.G Czakon ◽  
C.R Howell ◽  
A Hutcheson ◽  
J.H Kelley ◽  
...  
Keyword(s):  
Big Bang ◽  
Low Energy ◽  
Big Bang Nucleosynthesis

scholarly journals α+d→Li6+γ astrophysical S factor and its implications for Big Bang nucleosynthesis

2017 ◽  
Vol 96 (4) ◽  
Author(s):  
A. Grassi ◽  
G. Mangano ◽  
L. E. Marcucci ◽  
O. Pisanti
Keyword(s):  
Big Bang ◽  
Big Bang Nucleosynthesis ◽  
S Factor

EFFECTIVE FIELD THEORY IN NUCLEAR ASTROPHYSICS

2004 ◽  
Vol 19 (13n16) ◽  
pp. 1215-1222
Author(s):  
JIUNN-WEI CHEN
Keyword(s):  
Field Theory ◽  
Inelastic Scattering ◽  
High Precision ◽  
Effective Field Theory ◽  
Solar Neutrino ◽  
Nuclear Astrophysics ◽  
Big Bang ◽  
Effective Field ◽  
Big Bang Nucleosynthesis ◽  
Neutrino Detection

In this talk I review some general ideas of effective field theory and give examples of high precision calculations which have astrophysical applications. The examples are np→dγ for big-bang nucleosynthesis and νd inelastic scattering relevant for the solar neutrino detection processes employed by the Sudbury Neutrino Observatory.

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 7Be(n,p) cross section measurement for the Cosmological Lithium Problem at the n_TOF facility at CERN

2018 ◽  
Vol 184 ◽  
pp. 02004
Author(s):  
Damone Lucia Anna ◽  
N. Colonna ◽  
M. Barbagallo ◽  
M. Mastromarco ◽  
J. Andrzejewski ◽  
...  
Keyword(s):  
Cross Section ◽  
Nuclear Astrophysics ◽  
Big Bang ◽  
Big Bang Nucleosynthesis ◽  
Experimental Procedure ◽  
Cross Section Measurement ◽  
Halo Stars ◽  
Section Measurement ◽  
Primordial Abundance ◽  
The One

One of the most puzzling problems in Nuclear Astrophysics is the "Cosmological Lithium Problem", i.e the discrepancy between the primordial abundance of 7Li observed in metal poor halo stars [1], and the one predicted by Big Bang Nucleosynthesis (BBN). One of the reactions that could have an impact on the problem is 7Be(n,p)7Li. Despite of the importance of this reaction in BBN, the cross-section has never been directly measured at the energies of interest for BBN. Taking advantage of the innovative features of the second experimental area at the n_TOF facility at CERN, an accurate measurement of 7Be(n,p) cross section has been recently performed at n_TOF, with a pure 7Be target produced by implantation of a 7Be beam at ISOLDE. The experimental procedure, the setup used in the measurement and the results obtained so far will be here presented.

scholarly journals 4He abundances: Optical versus radio recombination line measurements

2009 ◽  
Vol 5 (S268) ◽  
pp. 101-106 ◽  
Author(s):  
Dana S. Balser ◽  
Robert T. Rood ◽  
T. M. Bania
Keyword(s):  
Big Bang ◽  
Abundance Ratio ◽  
Small Sample ◽  
Galactic Evolution ◽  
Recombination Line ◽  
Big Bang Nucleosynthesis ◽  
Radio Recombination Line ◽  
Ratio Data ◽  
The Galaxy ◽  
Green Bank Telescope

AbstractAccurate measurements of the 4He/H abundance ratio are important in constraining Big Bang nucleosynthesis, models of stellar and Galactic evolution, and H ii region physics. We discuss observations of radio recombination lines using the Green Bank Telescope toward a small sample of H ii regions and planetary nebulae. We report 4He/H abundance ratio differences as high as 15–20% between optical and ratio data that are difficult to reconcile. Using the H ii regions S206 and M17 we determine 4He production in the Galaxy to be dY/dZ = 1.71 ± 0.86.

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