scholarly journals Cross Section Measurements in the 54Cr(p, ?)55Mn Reaction

1979 ◽  
Vol 32 (4) ◽  
pp. 335 ◽  
Author(s):  
R. J. Wilkinson ◽  
A S. R. Kennett ◽  
A Z. E. Switkowski ◽  
D. G. SargoodA and F. M. MannC
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Reaction Cross Section ◽  
Proton Energy ◽  
Gamma Ray ◽  
Reaction Cross ◽  
Model Calculations ◽  
Global Parameter ◽  
Dramatic Effect ◽  
Bombarding Energy

Cross sections for production of individual y rays in the 54Cr(p, y)55Mn reaction have been measured over the proton energy range 1�0-3�8 MeV. Gamma-ray yields are observed to fall by factors of between 5 and 10 at the crossing of the neutron threshold for a proton bombarding energy of 2�2 MeV. Statistical model calculations with global parameter sets successfully account for the dramatic effect of neutron competition on the (p, y) cross section, and at the same time correctly predict the 54Cr(p,n)54Mn reaction cross section.

Systematic study of the (n,2n) reaction cross section for 121Sb and 123Sb isotopes

2022 ◽  
Author(s):  
RATANKUMAR SINGH ◽  
N.L. Singh ◽  
Rakesh Chauhan ◽  
Mayur Mehta ◽  
Saraswatula suryanarayan ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Systematic Study ◽  
Reaction Cross Section ◽  
Level Density ◽  
Reaction Cross ◽  
Measured Cross Section ◽  
Model Calculations ◽  
The Cross ◽  
Equilibrium Emission

Abstract The cross sections of the 121Sb(n,2n) 120Sbm and 123Sb(n,2n) 122Sb reactions were measured at 12.50, 15.79 and 18.87 MeV neutron energies relative to the standard 27Al(n,α) 24Na monitor reaction using neutron activation and offline γ-ray spectrometry technique. Irradiations of the samples were performed at the BARC-TIFR Pelletron Linac Facility, Mumbai, India. The quasi-monoenergetic neutron was generated via the 7Li(p,n) reaction. Statistical model calculations were performed by nuclear reaction codes TALYS (ver. 1.9) and EMPIRE (ver. 3.2.2) using various input parameters and nuclear level density models. The cross sections of the ground and the isomeric state as well as the isomeric cross section ratio were studied theoretically from reaction threshold to 26 MeV energies. The effect of pre-equilibrium emission is also discussed in detail using different theoretical models. The present measured cross section were discussed and compared with reported experimental data and evaluation data of the JEFF-3.3, ENDF/B-VIII.0, JENDL/AD-2017 and TENDL-2019 libraries. A detailed analysis of the uncertainties in the measured cross section data was performed using the covariance analysis method. Furthermore, a systematic study of the (n,2n) reaction cross section for 121Sb and 123Sb isotopes were also performed within 14-15 MeV neutron energies using various systematic formulae. This work helps to overcome discrepancies in Sb data and illustrate a better understanding of pre-equilibrium emission in (n,2n) reaction channel.

scholarly journals Activation cross section of the (n,2n) reaction on Hf isotopes

2019 ◽  
Vol 23 ◽  
pp. 47
Author(s):  
A. Kalamara ◽  
M. Serris ◽  
A. Spiliotis ◽  
D. Sigalos ◽  
N. Patronis ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Reaction Cross Section ◽  
Beam Energy ◽  
Reaction Cross ◽  
Activation Technique ◽  
Incident Neutron ◽  
Activation Cross Section ◽  
Reference Reaction

Cross sections of the 174Hf(n,2n)173Hf and 176Hf(n,2n)175Hf reactions have been experimentally determined relative to the 27Al(n,α)24Na reference reaction at incident neutron energies of 15.3 and 17.1 MeV by means of the activation technique. The irradiations were carried out at the 5 MV tandem T11/25 Accelerator Laboratory of NCSR "Demokritos" with monoenergetic neutron beams provided via the 3H(d,n)4He reaction, using a new Ti-tritiated target of 373 GBq activity. In the determination of the 176Hf(n,2n)175Hf reaction cross section the contamination of the 174Hf(n,γ)175Hf and 177Hf(n,3n)175Hf reactions has been taken into account. Moreover, the neutron beam energy has been studied by means of Monte Carlo simulation codes and the neutron flux has been determined via the 27Al(n,α)24Na reference reaction.

Reaction cross section calculations via second beta decay using the activation method for the p-process

2019 ◽  
Vol 97 (11) ◽  
pp. 1206-1209
Author(s):  
Ezgi Tantoğlu ◽  
Nalan Özkan ◽  
R. Taygun Güray
Keyword(s):  
Beta Decay ◽  
Cross Section ◽  
Cross Sections ◽  
Half Life ◽  
Reaction Cross Section ◽  
Experimental Studies ◽  
Reaction Cross ◽  
Activation Method ◽  
Alternative Method ◽  
The Cross

There are 35 proton-rich isotopes between 74Se and 196Hg that cannot be synthesized through neutron captures and β− decays (s- and r-processes). A third process is therefore required for the production of these nuclei, the so-called p-process. The abundance and the origin of the p-nuclei are still not fully understood even though significant experimental and theoretical efforts in astrophysical modeling have been expended in the last two decades. The experimental studies with the activation method to measure cross sections of the relevant reactions have some limitations: the reaction product must be radioactive, should have an appropriate half-life, and its decay should be followed by proper γ-radiations. If the cross section cannot be calculated with the radiation followed by the first beta decay of the product, it can be measured using the second beta decay as an alternative method. In this study, the method and candidate reactions for the cross-section measurements via the second beta decay of the reaction product using the activation method are discussed.

scholarly journals Theoretical study of the isomeric cross section of the 197Au(n,2n) reaction

2019 ◽  
Vol 18 ◽  
pp. 13
Author(s):  
A. Tsinganis ◽  
M. Diakaki ◽  
M. Kokkoris ◽  
A. Lagoyannis ◽  
C. T. Papadopoulos ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Isomeric State ◽  
Level Scheme ◽  
Reaction Cross Section ◽  
Theoretical Study ◽  
Strong Dependence ◽  
Mass Region ◽  
Reaction Cross ◽  
Theoretical Results

In the present work, the 197Au(n,2n) reaction cross section is studied within the framework of the Gen- eralized Superfluid Model (GSM). The cross sections for the population of the second isomeric state (12−) of 196Au and the sum of the ground (2−) and first isomeric state (5−) population cross sections were independently studied in the 8 to 25 MeV region with the use of the STAPRE-F, EMPIRE and TALYS codes, which were also compared in their implementation of the GSM. The theoretical results are compared with previous work in the same mass region and the strong dependence on the level scheme of the nuclei involved was revealed.

scholarly journals 14.8 MeV Neutron Activation Cross Section Measurements for Ge Isotopes

2009 ◽  
Vol 1 (2) ◽  
pp. 173-181 ◽  
Author(s):  
M. M. Haque ◽  
M. T. Islam ◽  
M. A. Hafiz ◽  
R. U. Miah ◽  
M. S. Uddin
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Gamma Ray ◽  
Reaction Cross ◽  
Activation Cross Section ◽  
Section Data ◽  
Gamma Ray Spectroscopy ◽  
24Na Reaction ◽  
The Cross ◽  
Good Agreement

The cross sections of Ge isotopes were measured with the activation method at 14.8 MeV neutron energy. The quasi-monoenergetic neutron beams were produced via the 3H(d,n)4He reaction at the 150 kV J-25 neutron generator of INST, AERE. The characteristics γ-lines of the product nuclei were measured with a closed end coaxial 17.5 cm2 high purity germanium (HPGe) detector gamma ray spectroscopy. The cross sections were determined with reference to the known 27Al(n,α)24Na reaction. Cross section data are presented for 72Ge(n,p)72Ga, 74Ge(n,α)71mZn and 76Ge(n,2n)75m+gGe reactions. The cross section values obtained for the above reactions were 24.78±1.75 mb, 1.69±0.11 mb and 860±50 mb, respectively. The results obtained were compared with the values reported in literature as well as theoretical calculation performed by the statistical code SINCROS-II. The experimental data were found fairly in good agreement with the calculated and literature data.  Keywords: Activation cross section; Neutron induced reaction; Gamma-ray spectroscopy; 14.8 MeV. © 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v1i2.1532  

TOWARDS THE DETERMINATION OF THE π-p → f2(1270)n REACTION CROSS-SECTION

1993 ◽  
Vol 08 (25) ◽  
pp. 2343-2350 ◽  
Author(s):  
N. N. ACHASOV ◽  
G. N. SHESTAKOV
Keyword(s):  
Total Cross Section ◽  
Cross Section ◽  
Cross Sections ◽  
Reaction Cross Section ◽  
Branching Ratios ◽  
Reaction Cross ◽  
Precise Estimation ◽  
The One ◽  
Reaction Cross Sections

In this letter, the necessity of a more precise estimation of the data on the reaction π-p → f2(1270)n → π0π0n is mentioned. The total cross-section σ(π-p → f2(1270)n) obtained from the data on the reaction π-p → π0π0n is shown to be approximately three times smaller than that following from the π-p → π+π-n data and also four times smaller than the prediction of the one-pion-exchange model. It is very important to resolve this disagreement because the results on the reaction π-p → f2(1270)n → π0π0n are used directly for the normalization of other reaction cross-sections and determination of branching ratios for some resonances.

ALPHA-NUCLEUS TOTAL REACTION CROSS SECTION IN THE RIGID PROJECTILE MODEL USING MICROSCOPIC N-α AMPLITUDE

2001 ◽  
Vol 10 (01) ◽  
pp. 43-53 ◽  
Author(s):  
I. AHMAD ◽  
M. A. ABDULMOMEN ◽  
L. A. AL-KHATTABI
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Reaction Cross Section ◽  
Scattering Amplitude ◽  
Reaction Cross ◽  
Glauber Model ◽  
Total Reaction Cross Section ◽  
Total Reaction ◽  
Rigid Projectile ◽  
Optical Limit Approximation

Coulomb modified Glauber model has been applied to calculate α total reaction cross-section for 12 C , 16 O and 40 Ca nuclei in the rigid projectile model using microscopic N-α amplitude which is evaluated in terms of NN scattering amplitude parameters. Using realistic densities for target nuclei and the same input information, we find that the predictions of the rigid projectile approximation for α reaction cross sections are, in general, in better agreement with the experimental data than those of the optical limit approximation.

scholarly journals The Neutron Facility at NCSR "Demokritos"- Implementation in the Case of the 232Th(n,2n) and 241Am(n,2n) Reactions

2020 ◽  
Vol 13 ◽  
pp. 136
Author(s):  
R. Vlastou ◽  
C. T. Papadopoulos ◽  
G. Perdikakis ◽  
M. Kokkoris ◽  
S. Kossionides ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Computer Code ◽  
Reaction Cross ◽  
Cross Section Data ◽  
Model Calculations ◽  
Section Data ◽  
Neutron Facility ◽  
Mev Protons ◽  
Reaction Cross Sections

In the 5.5 MV tandem T11/25 Accelerator Laboratory of NCSR "Demokritos" monoenergetic neutron beams can be produced in the energy ranges 120-650 keV, 4-11.5 MeV and 16-20.5 MeV by using the 7Li(p,n), 2H(d,n) and 3H(d,n) reactions, respectively. The corresponding beam energies and ions delivered by the accelerator, are 1.92-2.37 MeV protons, 0.8-9.6 MeV deuterons and 0.8-3.7 MeV deuterons, for the three reactions, respectively. Experimental results for neutron energies from threshold up to 11.5 MeV and at 17.1 MeV will be given for the 232Th(n,2n)231Th reaction, while for the 241 Am(n,2n)240 Am reaction, preliminary cross section data at 10.4, 10.6 and 17.1 MeV will be discussed. In the framework of the CERN n-TOF collaboration, the cross section of these reactions have been measured relative to the 197Au(n,2n)196Au, 27Al(n,a)24Na and 93Nb(n,2n) reaction cross sections, by using the activation method. In addition to the experimental work, theoretical Statistical model calculations are being carried out using the computer code STAPRE/F. The results are compared to the experimental data.

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