scholarly journals Reaction rate of p14N →15Oγ capture to all bound states in potential cluster model

2020 ◽  
Vol 29 (01) ◽  
pp. 1930007 ◽  
Author(s):  
Sergey Dubovichenko ◽  
Nataliya Burkova ◽  
Albert Dzhazairov-Kakhramanov ◽  
Bekmurza Beysenov
Keyword(s):  
Excited States ◽  
Ground State ◽  
Cluster Model ◽  
Bound States ◽  
Reaction Rate ◽  
Reaction Rates ◽  
Potential Cluster Model ◽  
Excitation Energies ◽  
Proton Capture ◽  
Calculation Results

Review of calculation results for astrophysical [Formula: see text]-factor of the [Formula: see text]N[Formula: see text]O capture reaction in the [Formula: see text]N channel of [Formula: see text]O was presented. It was carried out in the frame of the modified potential cluster model (MPCM) taking into account resonances in the [Formula: see text]O spectrum up to 3.2[Formula: see text]MeV at energy of incident protons varying of 30[Formula: see text]keV to 5[Formula: see text]MeV. It is possible to describe experimental data for the astrophysical [Formula: see text]-factors of the radiative proton capture on [Formula: see text]N to five excited states of [Formula: see text]O at excitation energies of 5.18[Formula: see text]MeV to 6.86[Formula: see text]MeV, only under assumption, that all five resonances are [Formula: see text] scattering waves. Quality new physical interpretation of the capture mechanism is discussed in this channel to the ground state of [Formula: see text]O. We assumed that the ground state of [Formula: see text]O is determined by the [Formula: see text]N[Formula: see text] channel with excited [Formula: see text]N[Formula: see text] cluster, which immediately allowed us to correctly describe order of values of the experimental [Formula: see text]-factor for capture to this state. Taking into account these results, the total [Formula: see text]-factor of the proton capture on [Formula: see text]N and the reaction rates to the ground and five excited states of [Formula: see text]O were determined at temperatures of 0.01[Formula: see text][Formula: see text] to 10[Formula: see text][Formula: see text]. The parametrization of the total reaction rate with a simple form is performed, which allows as to obtain [Formula: see text] equal to 0.06 with 5% errors of the calculated rate.

Reaction rate of n12C radiative capture at temperature from 0.01 to 10 T9

2021 ◽  
pp. 142-148
Author(s):  
S.B. Dubovichenko ◽  
◽  
N.A. Burkova ◽  
R.R. Shamitova ◽  
◽  
...  
Keyword(s):  
Cross Sections ◽  
Cluster Model ◽  
Bound States ◽  
Reaction Rate ◽  
Applied Research ◽  
Radiative Capture ◽  
Potential Cluster Model ◽  
Total Cross Sections ◽  
Forbidden States ◽  
Wide Resonance

Within the framework of a modified potential cluster model with forbidden states, radiation n12C capture at energies from 10-5 keV to 5 MeV is considered, taking into account a wide resonance at Ex = 8.2 MeV. It is shown that on the basis of potentials that are consistent with the energies of the bound states, it is possible to correctly transfer the available experimental data. Based on the obtained total cross sections, the n12C capture reaction rate was calculated. The results for reaction rate are approximated by simple expressions, which simplifies their use in applied research.

scholarly journals Astrophysical S-factor of the radiative proton capture on 14C at low energies

2014 ◽  
Vol 29 (24) ◽  
pp. 1450125 ◽  
Author(s):  
Sergey Dubovichenko ◽  
Nasurlla Burtebaev ◽  
Albert Dzhazairov-Kakhramanov ◽  
Dilshod Alimov
Keyword(s):  
Ground State ◽  
Cluster Model ◽  
Phase Shift Analysis ◽  
Potential Cluster Model ◽  
Proton Capture ◽  
Position Location ◽  
Capture Reaction ◽  
Shift Analysis ◽  
S Factor ◽  
Low Energies

The phase shift analysis for position location of the [Formula: see text] resonance at 1.5 MeV was carried out on the basis of the known experimental measurements of the excitation functions of the p14 C elastic scattering at four angles from 90° to 165° and more than 100 energy values in the range from 600–800 keV to 2200–2400 keV. Also, the possibility to describe the available experimental data on the astrophysical S-factor for the proton capture reaction on 14 C to the ground state (GS) of 15 N at astrophysical energies was considered in the frame of modified potential cluster model (MPCM).

scholarly journals Kinetic Study of the Reaction of Rh(a4F9/2) with N2O, O2 and NO

1998 ◽  
Vol 17 (4) ◽  
pp. 219-237 ◽  
Author(s):  
Mark L. Campbell
Keyword(s):  
Gas Phase ◽  
Excited States ◽  
Ground State ◽  
Rate Constants ◽  
Room Temperature ◽  
Reaction Rate ◽  
Removal Rate ◽  
Reaction Rates ◽  
Bimolecular Reaction ◽  
Temperature Rate

The gas phase reactivity of Rh(a4F9/2) with N2O, O2 and NO is reported. Removal rate constants for the excited states of rhodium below 13,000cm-1 are also reported. The reaction rate of Rh(a4F9/2) with N2O is relatively temperature insensitive. The rate constants for the bimolecular reaction are described in Arrhenius form by (1.3±0.3)×10−12exp⁡(−1.3±0.8KJ/mol/RT)cm3s−1 The reaction rates of the a4F9/2 state with O2 and NO are pressure dependent. For O2, the limiting low-pressure thirdorder, K0, and limiting high-pressure second-order, K∞, room temperature rate constants in argon buffer are (6.6±0.6)×10−30cm6s−1 and (2.1±0.2)×10−11cm3s−1, respectively. For NO, K2 and K∞ are (1.3±0.2×10−30cm6s−1) and (2.1±0.4)×10−11cm3s−1, respectively. The removal rates of the excited states are faster than the ground state by a factor of 2 or more.

Radiative proton capture to the ground state and first three excited states of 12C

1977 ◽  
Vol 285 (2) ◽  
pp. 189-197 ◽  
Author(s):  
K.A. Snover ◽  
P. Paul ◽  
H.M. Kuan
Keyword(s):  
Excited States ◽  
Ground State ◽  
Proton Capture

The ground state and low-lying excited states of CCCN radical and its ions: a CASSCF/CASPT2 study

2016 ◽  
Vol 94 (9) ◽  
pp. 803-807
Author(s):  
Angyang Yu
Keyword(s):  
Excited States ◽  
Ground State ◽  
Linear Structure ◽  
Electronic Configuration ◽  
Geometric Optimization ◽  
Oscillator Strengths ◽  
Basis Set ◽  
Excitation Energies ◽  
Complete Active Space ◽  
Vertical Excitation

The ground state and low-lying excited states of the CCCN radical and its ions have been investigated systematically using the complete active space self-consistent field (CASSCF) and multi-configuration second-order perturbation theory (CASPT2) methods in conjunction with the ANO-RCC-TZP basis set. The calculated results show that the state 12Σ+ has the lowest CASPT2 energy among the electronic states. By means of the geometric optimization of this radical, it could be found that the molecule exhibits linear structure, with the bond lengths R1 = 1.214 Å, R2 = 1.363 Å, R3 = 1.162 Å, which are very close to the experimental values. The calculated vertical excitation energies and the corresponding oscillator strengths show that there are three relatively strong peaks at energies 0.63, 4.04, and 5.49 eV, which correspond to the transitions 12Σ+ → 12Π, 12Σ+ → 22Π, and 12Σ+ → 22Σ+, respectively. Additionally, the electronic configuration and the harmonic vibration frequencies of each state are also investigated.

MR-CISD and MR-AQCC Calculation of Excited States of Malonaldehyde: Geometry Optimizations Using Analytical Energy Gradient Methods and a Systematic Investigation of Reference Configuration Sets

2003 ◽  
Vol 68 (3) ◽  
pp. 447-462 ◽  
Author(s):  
Silmar A. do Monte ◽  
Michal Dallos ◽  
Thomas Müller ◽  
Hans Lischka
Keyword(s):  
Excited States ◽  
Ground State ◽  
Transition Energy ◽  
Gradient Methods ◽  
Systematic Investigation ◽  
Oscillator Strengths ◽  
Excitation Energies ◽  
Band Maximum ◽  
Vertical Excitation ◽  
Energy Gradient

Extended MR-CISD and MR-AQCC calculations have been performed on the ground state and the first two excited states of malonaldehyde. Full geometry optimizations have been carried for Cs and C2v structures both at MR-CISD and MR-AQCC levels. Vertical and minimum-to-minimum excitation energies and oscillator strengths have been computed. Systematic studies have been undertaken concerning several types of reference spaces. Agreement with the experimental 0-0 transition energy to the S1 state (expt. 3.50 eV, calc. 3.56 eV) and for the vertical excitation to S2 (expt. band maximum 4.71 eV, best estimate 4.86 eV) is very good. In agreement with the CASSCF/CASPT2 results by Sobolewski and Domcke (J. Phys. Chem. A 1999, 103, 4494), we find that the hydrogen bond in malonaldehyde is weakened by excitation to the S1 state. The barrier for proton transfer in the S1 state is increased in comparison with the ground state.

Shell model description of the 0+ and 0− excited states in sd shell nuclei

2018 ◽  
Vol 96 (7) ◽  
pp. 774-778 ◽  
Author(s):  
M. Bouhelal ◽  
N. Saidane ◽  
S. Belaid ◽  
F. Haas
Keyword(s):  
Shell Model ◽  
Excited States ◽  
Ground State ◽  
Model Description ◽  
Excitation Energies ◽  
Model Calculations ◽  
The Future

The purpose of this work is to describe, in light of shell model calculations using the PSDPF interaction, the particular states with J = 0 in sd shell nuclei. These states are difficult to observe. It is well known that the ground state in even–even nuclei has Jπ = 0+ and therefore we are interested in describing their first excited [Formula: see text] states. We have also studied the first and second excited 0− states in all sd nuclei. The experimental and theoretical excitation energies of these states were confronted. This study allowed us to make predictions of the existence of [Formula: see text] and (or) [Formula: see text] states in nuclei, which do not possess these states, or to have an idea of their excitation energies for possible experiments in the future.

Levels in 45Sc from Radiative Proton Capture in 44Ca

1974 ◽  
Vol 52 (2) ◽  
pp. 131-139 ◽  
Author(s):  
R. L. Schulte ◽  
J. D. King ◽  
H. W. Taylor
Keyword(s):  
Decay Scheme ◽  
Bound States ◽  
Gamma Ray ◽  
Angular Distributions ◽  
Distribution Data ◽  
Excitation Energies ◽  
Proton Capture ◽  
Resonant States ◽  
Γ Rays ◽  
Γ Ray

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.

scholarly journals Energy spectra in $p$-shell $\Lambda$ hypernuclei and $^{19}_{\Lambda}\textrm{F}$ and spin-dependent $\Lambda N$ interactions

2019 ◽  
Vol 2019 (7) ◽  
Author(s):  
Yoshiko Kanada-En’yo ◽  
Masahiro Isaka ◽  
Toshio Motoba
Keyword(s):  
Molecular Dynamics ◽  
Excited States ◽  
Cluster Model ◽  
Energy Spectra ◽  
Excitation Energies ◽  
Spin Doublet ◽  
Doublet Splitting

Abstract Energy spectra of $0s$-orbit $\Lambda$ states in $p$-shell $\Lambda$ hypernuclei ($^{A}_\Lambda Z$) and those in $^{19}_{\Lambda}\textrm{F}$ are studied with the microscopic cluster model and antisymmetrized molecular dynamics using the $G$-matrix effective $\Lambda N$ ($\Lambda NG$) interactions. Spin-dependent terms of the ESC08a version of the $\Lambda NG$ interactions are tested and phenomenologically tuned to reproduce observed energy spectra in $p$-shell $^{A}_\Lambda Z$. Spin-dependent contributions of the $\Lambda N$ interactions to spin-doublet splitting and excitation energies are discussed. Energy spectra for unobserved excited states in $p$-shell $^{A}_\Lambda Z$ and $^{19}_{\Lambda}\textrm{F}$ are predicted with the modified $\Lambda NG$ interactions.

scholarly journals Effect of Excited States on Thermonuclear Reaction Rates

1983 ◽  
Vol 36 (4) ◽  
pp. 583 ◽  
Author(s):  
DG Sargood
Keyword(s):  
Statistical Model ◽  
Excited States ◽  
Cross Sections ◽  
Reaction Rate ◽  
Ground States ◽  
Reaction Rates ◽  
Thermonuclear Reaction ◽  
Thermal Distribution ◽  
Naturally Occurring ◽  
Thermonuclear Reaction Rate

Values of the ratio of the thermonuclear reaction rate of a reaction, with target nuclei in a thermal distribution of energy states, to the reaction rate with all target nuclei in their ground states are tabulated for neutron, proton and (X-particle induced reactions on the naturally occurring nuclei from 2�Ne to 70Zn, at temperatures of 1, 2, 3�5 and 5 x 109 K. The ratios are determined from reaction rates based on statistical model cross sections.

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