scholarly journals Nuclear astrophysics studies at NIPNE

2020 ◽  
Vol 227 ◽  
pp. 01016
Author(s):  
Livius Trache
Keyword(s):  
Nuclear Astrophysics ◽  
List Type ◽  
Salt Mine ◽  
Nuclear Engineering ◽  
Radioactive Beams ◽  
Indirect Measurements ◽  
Low Background ◽  
Direct Measurements ◽  
Gamma Coincidence ◽  
Low Energies

I will present results of doing nuclear astrophysics research at the National Institute for Physics and Nuclear Engineering, Bucharest-Magurele in the last 2-3 years. Own Nuclear Astrophysics Group (NAG) is focused on the basic types of experiments: -Direct measurements at low and very low energies with ion or alpha beams from the local 3 MV tandetron accelerator. We concentrate on activation measurements. The use of the ultra-low background laboratory in a salt mine at Slanic-Prahova, about 120 km away and of a beta-gamma coincidence unit at home is providing competitive sensitivity. -Indirect measurements done with beams at international facilities with radioactive beams: TAMU and RIBF RIKEN. With help from colleagues, I will mention some theory advances, too.

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.

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 The Study of the 6Li(p,γ)7Be Reaction at LUNA

2020 ◽  
Vol 1668 (1) ◽  
pp. 012034
Author(s):  
D. Piatti
Keyword(s):  
Cross Section ◽  
Main Sequence ◽  
Theoretical Calculations ◽  
Nuclear Astrophysics ◽  
Recent Measurement ◽  
Main Sequence Stars ◽  
Primordial Nucleosynthesis ◽  
Direct Measurements ◽  
S Factor ◽  
Low Energies

Abstract The 6Li(p,γ)7Be reaction is mainly involved in two astrophysical scenarios: the primordial nucleosynthesis and 6Li consumption in pre-main and main sequence stars. A recent measurement of 6Li(p,γ)7Be reaction S-factor reported a resonance-like structure at Ecm = 195 keV, which has not been confirmed neither by other direct measurements nor by theoretical calculations. A new experiment was performed at the Laboratory for Underground Nuclear Astrophysics (LUNA). The extremely low background environment allowed to measure the 6Li(p,γ)7Be cross section down to low energies with unprecedented sensitivity leading to clarify the existence of the claimed resonance. Details on the experimental setup and the preliminary results of the ongoing analysis are reported in this work.

Direct and Indirect Vibro-Acoustic Measurements for Road Noise NVH Predictions

2005 ◽  
Author(s):  
Alessandro Zanarini ◽  
Filip De Coninck ◽  
Krzysztof Mendrok ◽  
Paul Sas
Keyword(s):  
Complex Structure ◽  
Indirect Measurement ◽  
Acoustic Measurements ◽  
Road Noise ◽  
Indirect Measurements ◽  
Direct Measurements ◽  
Path Direction ◽  
Vehicle Technologies ◽  
Structure Measurement ◽  
Reverse Path

This paper describes vibro-acoustic direct and indirect measurements for road noise NVH predictions from a complete car. Attention is devoted to the dynamic response of the structure and interior pressure field toward tire patch displacement inputs. The direct measurements exploited the Team Corporation CUBE™ high frequency 6 degree-of-freedom (DOF) shaker recently installed at the KULeuven Vehicle Technologies Laboratory; the input was provided directly at the tire contact patch, while the responses were measured as accelerations and pressures on the structure. In the indirect measurements a low-mid frequency volume velocity source (LMFVVS) was used to acoustically excite the structure in the reverse path direction from the inside of the interior car cavity, while accelerations on the car and forces/torques where acquired by a 6-DOF dynamometer at the tire patch. From both types of excitations Frequency Response Functions (FRF) were calculated in the frequency range [0–500 Hz]. The non-linearity of the full car system was investigated with different direct and indirect measurement tests, in order to assess the feasibility of the reciprocity principle in such a complex structure. Measurement set-ups, results and comparisons are described and discussed in detail.

scholarly journals The therapeutic effect of a person staying in a salt mine due to the low background level of atomic radiation

2020 ◽  
Vol 17 (5) ◽  
pp. 279-283
Author(s):  
Gayaz H. Harisov ◽  
Aleksander G. Zavorotny
Keyword(s):  
Experimental Study ◽  
Therapeutic Effect ◽  
Salt Spray ◽  
Background Level ◽  
Salt Mine ◽  
Low Background ◽  
Salt Mines ◽  
Low Levels

The therapeutic effect of people staying in salt mines is currently explained by the fact that people inhale salt spray particulates. Based on an experimental study, the article proves that this therapeutic effect is the result of super-low levels of atomic radiation in the space of salt mines.

scholarly journals Underground Nuclear Astrophysics in China

2015 ◽  
Vol 11 (A29A) ◽  
pp. 333-336
Author(s):  
Liu WeiPing ◽  
Keyword(s):  
Stellar Evolution ◽  
Nuclear Reactions ◽  
Nuclear Astrophysics ◽  
High Current ◽  
Low Background ◽  
Set Up ◽  
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 will be set up. We plan to study directly a number of nuclear reactions important to hydrostatic stellar evolution at their relevant stellar energies, such as 25Mg(p,γ)26Al, 19F(p,α)16O, 13C(α,n)16O and 12C(α,γ)16O.

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.

Chemische Reaktionskinematik

1968 ◽  
Vol 23 (12) ◽  
pp. 2084-2090 ◽  
Author(s):  
A. Ding ◽  
A. Henglein ◽  
D. Hyatt ◽  
K. Lacmann
Keyword(s):  
Cross Sections ◽  
Degrees Of Freedom ◽  
Forward Scattering ◽  
Small Shift ◽  
High Energies ◽  
Direct Measurements ◽  
Wide Range ◽  
Ion Energies ◽  
Low Energies ◽  
Velocity Spectra

The velocity spectra and cross sections of reactions of the type X*+D2 → XD++D (X+=Ar+, N2+, CO+) have been found to be independent of the temperature of the target gas ( — 190° to 20°C). The additional forward scattering (as compared to spectator stripping) of the product ion at high energies cannot be explained by the thermal motion of the D2 molecules. A recoil stripping mechanism is proposed. At low energies, an intermediate XD2* is postulated that lives shorter than half a period of rotation and is forward scattered but quickly equilibrates the excess energy among the vibrational degrees of freedom. The reactions of Ar+ and N2+ with CD4 can well be understood by the stripping model over a wide range of energy. At low energies, no preferential forward scattering of the product ion is found as in the corresponding reactions with D2. The strongly unsymmetric broadening of the product ion band together with a small shift to lower velocities indicate a strong interaction of the incident ion with the CD3 group at low energies. The formation of an intermediate complex XCD4+ which isotropically decays is expected at energies of a few tenth of one eV. Direct measurements at such low primary ion energies have not yet been possible.

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