The transition between the Main Sequence and the Red Giant Branch in low mass stars is powered by the onset of CNO burning, whose bottleneck is 14N(p, $\gamma)^{15}$O. The LUNA collaboration has ...recently improved the low energy measurements of the cross section of this key reaction. We analyse the impact of the revised reaction rate on the estimate of the Globular Cluster ages, as derived from the turnoff luminosity. We found that the age of the oldest Globular Clusters should be increased by about 0.7-1 Gyr with respect to the current estimates.
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FMFMET, NUK, UL, UM, UPUK
We present the state-of-art activity of n_TOF Collaboration Working Group dedicated to study how to solve the puzzle about the existence of the so called new particle X17, spotted for the first time ...few years ago by a team at ATOMKI in Hungary and since then never confirmed by other independent experimental collaborations but also never refuted. An “ad hoc” detection set-up is under realization for this goal, in order to reach an angular resolution of the two emerging trajectories from the X17 decay and an energy resolution for the invariant mass reconstruction enough to cast light in a definitive way about this puzzle. To design the present detection setup we work in close contact with the Pisa Nuclear Theory team, that has deeply studied the implication of X17 existence and extracted by the ATOMKI results its eventual nature, kinematics and general properties.
Preliminary results of a new boron coated neutron detector Gervino, G.; Balma, M.; Devona, D. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2013, Volume:
718
Journal Article
Peer reviewed
The proliferation of neutron detection applications based upon 3He counter has triggered a critical shortage of 3He gas. Nowadays there is an increasing demand for alternative neutron detectors that ...can cover large solid angles, have low sensitivity to gamma background and low cost. We present a low cost neutron detector based upon 3cm diameter, 150cm long cylindrical metal tube coated on the inside with a thin layer of 10B-enriched boron carbide (10B4C) fulfilled by 1atm nitrogen.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
24.
High efficiency large volume multiparametric neutron detector Lavagno, A.; Gervino, G.; Marino, C.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2010, Volume:
617, Issue:
1
Journal Article
Peer reviewed
Monitoring neutron emission with efficient detectors is the most straightforward way to study physics problems such as fission of heavy nuclei, where neutrons are preferentially emitted because of ...the Coulomb barrier, and the (
α
,
n
) reactions. A large volume (more than 5
l) neutron detector has been realized by organic liquid scintillator: the detector shows a very good performance for high efficiency measurements at low and very low neutron rate in the
0.03
–
10
MeV
energy range.
γ
–
n
discrimination has been jointly performed by standard pulse shape discrimination and the digital charge comparison method, the results obtained by the two techniques are presented and discussed. A very good
γ
–
n
discrimination down to 100
kee with good efficiency has been achieved.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The $\Sigma$ beam asymmetry in $\eta^{\prime}$ photoproduction off the proton was measured at the GrAAL polarized photon beam with incoming photon energies of 1.461 and 1.480 GeV. For both energies ...the asymmetry as a function of the meson emission angle shows a clear structure, more pronounced at the lowest one, with a change of sign around 90$^o$. The results are compared to the existing theories that fail to account for the data.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
We study a nonlinear nuclear equation of state in the framework of a relativistic mean field theory. We investigate the possible thermodynamic instability in a warm and dense asymmetric nuclear ...medium where a phase transition from nucleonic matter to resonance dominated Δ matter can take place. Such a phase transition is characterized by both mechanical instability (fluctuations on the baryon density) and by chemical-diffusive instability (fluctuations on the isospin concentration) in asymmetric nuclear matter. Similarly to the liquid-gas phase transition, the nucleonic and the Δ-matter phase have a different isospin density in the mixed phase. In the liquid-gas phase transition, the process of producing a larger neutron excess in the gas phase is referred to as isospin fractionation. A similar effects can occur in the nucleon-Δ matter phase transition due essentially to a negative Δ-particles excess in asymmetric nuclear matter. In this context, we investigate also the effects of power law effects, due to the possible presence of nonextensive statistical mechanics effects.
Improvements in real time 222Rn monitoring at Stromboli volcano Lavagno, A.; Laiolo, M.; Gervino, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2013, Volume:
718
Journal Article
Peer reviewed
Monitoring gas emissions from soil allow to get information on volcanic activity, hidden faults and hydrothermal dynamics. Radon activities at Stromboli were collected by means of multi-parametric ...real-time stations, that measure radon as well as environmental parameters. The last improvements on the detection system are presented and discussed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
We investigate the bulk properties of protoneutron stars in the framework of a relativistic mean field theory based on nonextensive statistical mechanics, originally proposed by C. Tsallis and ...characterized by power-law quantum distributions. We study the relevance of nonextensive statistical effects on the β-stable equation of state at fixed entropy per baryon, for nucleonic and hyperonic matter. We concentrate our analysis in the maximum heating and entropy per baryon s = 2 stage and T ≈ 40 ÷ 80 MeV. This is the phase, at high temperature and high baryon density, in which the presence of nonextensive effects may alter more sensibly the thermodynamical and mechanical properties of the protoneutron star. We show that nonextensive power-law effects could play a crucial role in the structure and in the evolution of the protoneutron stars also for small deviations from the standard Boltzmann-Gibbs statistics.
RETRACTED: Neutron detection by large NaI crystal Lavagno, A.; Gervino, G.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2016, Volume:
824
Journal Article
Peer reviewed
This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal).
This article has been retracted at the ...request of the Editor.
The article includes many textual similarities with a work that had already appeared in Nuclear Instruments and Methods in Physics Research A, Volume 697, January 2013, p. 59-63 (10.1016/j.nima.2012.09.010), as well as the Master thesis Neutron detection with high-energy photons using NaI portal monitor, Aalto University, 2012 (https://aaltodoc.aalto.fi/bitstream/handle/123456789/5206/master_holm_philip_2012.pdf?isAllowed=y&sequence=1).
One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents an abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
.
The experimental study of nuclear reactions of astrophysical interest is greatly facilitated by a low-background, high-luminosity setup. The Laboratory for Underground Nuclear Astrophysics (LUNA) ...400kV accelerator offers ultra-low cosmic-ray induced background due to its location deep underground in the Gran Sasso National Laboratory (INFN-LNGS), Italy, and high intensity, 250-500μA, proton and
α
ion beams. In order to fully exploit these features, a high-purity, recirculating gas target system for isotopically enriched gases is coupled to a high-efficiency, six-fold optically segmented bismuth germanate (BGO)
γ
-ray detector. The beam intensity is measured with a beam calorimeter with constant temperature gradient. Pressure and temperature measurements have been carried out at several positions along the beam path, and the resultant gas density profile has been determined. Calibrated
γ
-intensity standards and the well-known
E
p
=
278
keV
14
N(p,
γ
)
15
O resonance were used to determine the
γ
-ray detection efficiency and to validate the simulation of the target and detector setup. As an example, the recently measured resonance at
E
p
=
189
.
5
keV in the
22
Ne(p,
γ
)
23
Na reaction has been investigated with high statistics, and the
γ
-decay branching ratios of the resonance have been determined.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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