scholarly journals Angular distributions of γ rays from theLi7(p,γ) reaction at low energies

1996 ◽  
Vol 53 (3) ◽  
pp. 1273-1277 ◽  
Author(s):  
K. I. Hahn ◽  
C. R. Brune ◽  
R. W. Kavanagh
2021 ◽  
Author(s):  
Robin Smith ◽  
Moshe Gai ◽  
Sarah Stern ◽  
Deran Schweitzer ◽  
Mohammad Ahmed

Abstract Stellar Evolution theory relies on our knowledge of nuclear reactions, with the carbon/oxygen (C/O) ratio, at the end of helium burning, being the single most important input. However, the C/O ratio is still not known with sufficient accuracy, due to large uncertainties in the cross section for the fusion of helium with 12C to form 16O, denoted as the 12C(α,γ)16O reaction. We present initial results at moderately low energies using a novel method, which is significantly different from the experimental efforts of the past four decades. Precise angular distributions of the 12C(α,γ)16O reaction were obtained by measuring the inverse 16O(γ,α)12C reaction with gamma-beams and a Time Projection Chamber detector. These allowed us to measure, for the first time, the interference angle of the l = 1 and 2 partial waves contributing to this reaction (φ12), which agrees with predictions based on the unitarity of the scattering matrix.


1963 ◽  
Vol 41 (5) ◽  
pp. 724-736 ◽  
Author(s):  
G. M. Griffiths ◽  
M. Lal ◽  
C. D. Scarfe

The yield and angular distribution of the γ rays from the reaction D(p, γ) He3 have been measured with thick heavy-ice targets in the energy range from 24 kev to 48 kev. Assuming a simplified energy dependence the results have been analyzed to give cross sections for p-wave and s-wave capture. At 25 kev in the laboratory system, the cross sections are[Formula: see text]The astrophysical S-factors in the center-of-mass system below 40 kev have been found to be[Formula: see text]for E in center-of-mass kilovolts and[Formula: see text]independent of energy giving a total S-factor for low energies[Formula: see text]with E in center-of-mass kilovolts.


2019 ◽  
Vol 26 ◽  
pp. 188
Author(s):  
A. Zyriliou ◽  
A. Khaliel ◽  
T. J. Mertzimekis

Some of the mid–weight nuclei lie in the region of the isotopic chart where the astrophysical p-process has a prominent role in the nucleosynthetic scenarios. Experimentally deduced reaction cross section data can provide stringent tests for the astrophysical models, especially at low energies. In this framework, the reaction 112Cd(p,γ)113In has been studied experimentally at four proton beam energies 2.8 ≤ Ep≤ 3.4 MeV, partly inside the astrophysically interesting Gamow window. Proton beams were provided by the 5.5 MV T11 Van de Graaff Tandem Accelerator of the Institute of Nuclear Physics of the National Center for Scientific Research (NCSR) “Demokritos”. In–beam spectroscopy was carried out with an array of four HPGe detectors sitting on a rotating table. In total, eight (8) different angles were used to record gamma–ray spectra. Special focus was given on constructing the angular distribution of each gamma–ray feeding the ground state of 113In directly, so as to determine the reaction cross sections from the in–beam data, exclusively. The resulting cross sections were compared to Hauser–Feshbach calculations using the code TALYS v1.9.


2020 ◽  
Vol 129 (1B) ◽  
pp. 57-61
Author(s):  
N. Hoang Tung ◽  
T. Dieu Thuy ◽  
D. Quang Tam ◽  
T. Ngoc Quynh Tran ◽  
T. V. Nhan Hao

For the first time, a realistic microscopic calculation for low-energy neutron-nucleus elastic scattering off open-shell nuclei is carried out within the framework of particle-vibration coupling (PVC). In this study, the pairing correlations of the ground state are taken into account. The dependence of the angular distributions on the pairing gaps is discussed.


2008 ◽  
Vol 17 (01) ◽  
pp. 110-119 ◽  
Author(s):  
M. DI TORO ◽  
M. COLONNA ◽  
C. RIZZO ◽  
V. BARAN

Heavy Ion Collisions (HIC) represent a unique tool to probe the in-medium nuclear interaction in regions away from saturation. In this work we present a selection of reaction observables in dissipative collisions particularly sensitive to the isovector part of the interaction, i.e. to the symmetry term of the nuclear Equation of State (EoS). At low energies the behavior of the symmetry energy around saturation influences dissipation and fragment production mechanisms. We will first discuss the recently observed Dynamical Dipole Radiation, due to a collective neutron-proton oscillation during the charge equilibration in fusion and deep-inelastic collisions. We will review in detail all the main properties, yield, spectrum, damping and angular distributions, revealing important isospin effects. Reactions induced by unstable 132Sn beams appear to be very promising tools to test the sub-saturation Isovector EoS. Predictions are also presented for deep-inelastic and fragmentation collisions induced by neutron rich projectiles. The importance of studying violent collisions with radioactive beams at low and Fermi energies is finally stressed.


1978 ◽  
Vol 298 (2) ◽  
pp. 217-227 ◽  
Author(s):  
A. Likar ◽  
A. Lindholm ◽  
L. Nilsson ◽  
I. Bergqvist ◽  
B. Pålsson

1974 ◽  
Vol 52 (2) ◽  
pp. 131-139 ◽  
Author(s):  
R. L. Schulte ◽  
J. D. King ◽  
H. W. Taylor

A total of 22 resonances has been observed in the 44Ca(p,γ)45Sc reaction within the incident proton energy range of 600 to 930 keV. Gamma-ray singles spectra and γ-ray angular distribution data were accumulated for resonances at Ep = 856 and 906 keV. Both of these resonant states have been found to have spin 3/2. The measured angular distributions of primary γ rays from the resonant states have given spin information on the intermediate bound states of 45Sc with excitation energies above 2 MeV. A γ-ray decay scheme has been derived from the γ-ray spectra. The data indicate new levels at 2151.0, 3525.2, 3548.5, 3584.0, and 3714.3 keV.


Author(s):  
N. Keller ◽  
R.D. Miller ◽  
M. Westerlind ◽  
L.R. Andersson ◽  
S.B. Elston ◽  
...  

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