Isomeric Cross-section Ratios Research Articles

Activation cross-sections for the 185Re(n, 2n) reaction and the isomeric cross-section ratio of 184m,gRe in the neutron energy range of 13\u201315 MeV

.Cross-sections and their isomeric ratios ( sigma_{mathrm{m}}/sigma_{mathrm{g}}) for the 185Re(n, 2n)184mRe and 185Re(n, 2n)184gRe reactions in the 13–15 MeV range were measured. The neutron activation technique was applied using the K-400 neutron generator at the Chinese Academy of Engineering Physics (CAEP). Natural Re samples and Nb monitor foils were activated jointly to determine the reaction cross-section and the incident neutron flux. The 3H(d, n)4He reaction was used to generate the neutron beam. The pure cross-section of the ground state was derived from the absolute cross-section of the metastable state using residual nuclear decay analysis. Numerical calculations using the nuclear-model-based computer code TALYS-1.8 with six level density models were used to obtain 185Re(n, 2n)184m, gRe reaction excitation functions and their isomeric cross-section ratios. Finally, experimentally determined cross-sections were compared with corresponding literature data.

Measurement of cross sections and isomeric cross-section ratios for the(n,2n)reactions onHg196,198at energies between 13 and 15 MeV

Measurement of cross sections and isomeric cross-section ratios for the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mo>(</mml:mo><mml:mrow><mml:mi>n</mml:mi><mml:mo>,</mml:mo><mml:mn>2</mml:mn><mml:mi>n</mml:mi></mml:mrow><mml:mo>)</mml:mo></mml:mrow></mml:math>reactions on<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Hg</mml:mi><mml:mprescripts /><mml:none /><mml:mrow><mml:mn>196</mml:mn><mml:mo>,</mml:mo><mml:mn>198</mml:mn></mml:mrow></mml:mmultiscripts></mml:math>at energies between 13 and 15 MeV

Isomer ratios and cross sections for the isomeric pair 122mSb and 122gSb in the 123Sb(n,2n) reaction

Cross-sections and their isomeric ratios σm/σg in the energy range of 13–15 MeV for isomeric pair 122mSb and 122gSb produced by the 123Sb(n,2n) reaction have been measured by activation and off-line γ-ray spectrometric technique using the K-400 Neutron Generator at the Chinese Academy of Engineering Physics (CAEP). Specifically, the versatile stacked foil irradiation technique and a high resolution HPGe detector were employed. The 3H(d,n)4He reaction was used to produce the neutron beam. Partial cross sections σm and σg were derived from the absolute cross section of the metastable state and residual nuclear decay analysis. The 123Sb(n,2 n)122m,gSb reaction excitation functions and their isomeric cross section ratios were numerically calculated with TALYS-1.8 code with different level density options. Results are discussed and compared with corresponding literature data.

Measurement of cross sections and isomeric cross-section ratios for the (n,2n) reactions on 85,87Rb in energies between 13 and 15 MeV

Abstract The (n,2n) cross sections and their isomeric cross-section ratios (σm/σg) in the neutron energy range 13–15 MeV have been measured for 85,87Rb by an activation and off-line γ-ray spectrometric technique using the Pd-300 Neutron Generator at the Chinese Academy of Engineering Physics (CAEP). The natural Rb samples and Nb monitor foils were activated together to determine the reaction cross section and the incident neutron flux. The neutrons were produced via the 3H(d,n)4He reaction. The pure cross section of the ground-state was derived from the absolute cross section of the metastable state and the residual nuclear decay analysis. The 85Rb(n,2n)84m,gRb and 87Rb(n,2n)86m,gRb reaction excitation functions and their isomeric cross-section ratios were also calculated theoretically using the TALYS-1.8 code with different level density options. Results are discussed and compared with the corresponding literature data.

Activation cross section and isomeric cross section ratio for the 76Ge(n,2n)75m,gGe process

.We measured neutron-induced reaction cross sections for the 76Ge(n,2n)75m,gGe reactions and their isomeric cross section ratios sigma_{m}/sigma_{g} at three neutron energies between 13 and 15MeV by an activation and off-line gamma-ray spectrometric technique using the K-400 Neutron Generator at the Chinese Academy of Engineering Physics (CAEP). Ge samples and Nb monitor foils were activated together to determine the reaction cross section and the incident neutron flux. The monoenergetic neutron beams were formed via the 3H(d,n)4He reaction. The pure cross section of the ground state was derived from the absolute cross section of the metastable state and the residual nuclear decay analysis. The cross sections were also calculated using the nuclear model code TALYS-1.8 with different level density options at neutron energies varying from the reaction threshold to 20MeV. Results are discussed and compared with the corresponding literature data.

Measurement of excitation functions and analysis of isomeric population in some reactions induced by proton on natural indium at low energy

The excitation functions for reaction residues populated via In115(p,p)115mIn, In115(p,pn)114mIn, In115(p,p2n)113mIn, In113(p,p)113mIn, In115(p,nα)111mCd, In115(p,3n)113Sn and In113(p,n)113Sn channels were measured over the proton energy range of 8–22 MeV using stacked foil activation technique. Theoretical analysis of the data were performed within the framework of two statistical model codes EMPIRE-3.2 and TALYS-1.8. Isomeric cross section ratio for isomeric pairs Inm,g115, Inm,g114, Inm,g113, S113nm,g and Cdm,g111 were determined for the first time. The dependence of isomeric cross section ratio on various factors are analysed.

Activation cross sections for the 110Pd(n,2n) reaction and the isomeric cross-sections ratio of 109m,gPd in the neutron energy range of 13–15 MeV

The 110Pd(n,2n)109m,gPd reaction cross-sections and the isomeric cross section ratios (σm/σg) in the neutron energy range of 13-15 MeV have been measured by an activation and off-line g-ray spectrometric technique using the 300Pd Neutron Generator at the Chinese Academy of Engineering Physics (CAEP). The natural Pd samples and Nb monitor foils were activated together to determine the reaction cross section and the incident neutron flux. The neutron beams were generated via the 3H(d,n)4He reaction. The pure cross section of the ground-state was derived from the absolute cross section of the metastable state and the residual nuclear decay analysis. The 110Pd(n,2n)109m,gPd reaction excitation functions and their isomeric cross section ratios were also calculated theoretically using the computer code TALYS-1.8 with different level density options. Results are discussed and compared with the corresponding literature data.

Activation cross section and isomeric cross-section ratio for the 151Eu(n,2n)150m,gEu process

The cross sections of 151Eu(n,2n)150m,gEu reactions and their isomeric cross section ratios σm/σt have been measured experimentally. Cross sections are measured, relative to a reference 93Nb(n,2n)92mNb reaction cross section, by means of the activation technique at three neutron energies 13.5, 14.1, and 14.8 MeV. Monoenergetic neutron beams were formed via the 3H(d,n)4He reaction and both Eu2O3 samples and Nb monitor foils were activated together to determine the reaction cross section and the incident neutron flux. The activities induced in the reaction products were measured using high−resolution gamma ray spectroscopy. Cross sections were also evaluated theoretically using the numerical nuclear model code, TALYS-1.8 with different level density options at neutron energies varying from the reaction threshold to 20 MeV. Results are discussed and compared with the corresponding literature.

Activation cross section and isomeric cross section ratios for the ( n,2n ) reaction on Eu153

The $^{153}\mathrm{Eu}(n,2n)^{152}\mathrm{Eu}^{\mathrm{m}1,\mathrm{m}2,g}$ cross section was measured by means of the activation technique at three neutron energies in the range 13--15 MeV. The quasimonoenergetic neutron beam was formed via the $^{3}\mathrm{H}(d,n)^{4}\mathrm{He}$ reaction, in the Pd-300 Neutron Generator at the Chinese Academy of Engineering Physics (CAEP). The activities induced in the reaction products were measured using high-resolution \ensuremath{\gamma}-ray spectroscopy. The cross section of the population of the second high-spin (${8}^{\ensuremath{-}}$) isomeric state was measured along with the reaction cross section populating both the ground (${3}^{\ensuremath{-}}$) and the first isomeric state (${0}^{\ensuremath{-}}$). Cross sections were also evaluated theoretically using the numerical code TALYS-1.8, with different level density options at neutron energies varying from the reaction threshold to 20 MeV. Results are discussed and compared with the corresponding literature.

Activation Cross Section and Isomeric Cross-Section Ratio for the (n,2n) Reaction on 113,115In

Cross sections of the 113In(n,2n)112m,gIn and 115In(n,2n)114m,gIn reactions and their isomeric cross-section ratios σm/σg have been measured by means of the activation technique at three neutron energies in the range 13 to 15 MeV. Indium samples and niobium monitor foils were activated together to determine the reaction cross section and the incident neutron flux. The monoenergetic neutron beam was produced via the 3H(d,n)4He reaction at the Pd-300 Neutron Generator of the Chinese Academy of Engineering Physics. The activities induced in the reaction products were measured using high-resolution gamma-ray spectroscopy. The pure cross section of the ground state was derived from the absolute cross section of the metastable state and the residual nuclear decay analysis. Cross sections were also evaluated theoretically using the numerical nuclear model code TALYS-1.8 with different level density options at neutron energies varying from the reaction threshold to 20 MeV. Results are discussed and compared with the corresponding literature.

Isomeric cross section ratios for the reactions 86(87)Sr(α,n(2n))89mgZr

Calculations of the excitation functions of high-spin and low-spin isomeric states in one and the same nucleus as well as the respective isomeric cross section ratios (ICSR) are carried out for the reactions 86(87)Sr(α,n(2n))89mgZr. The reliability of advanced data-containing codes EMPIRE and TALYS are analyzed. The results of the measurements of isomeric cross section ratios themselves and comparison of these results with the ones calculated by the discussed codes are proved to be a promising test of the codes and their capability to reproduce angular momentum dynamics of the discussed and related reactions.

Measurement of the cross-sections of the 106m,gAg, 105gAg, and 104m,gAg from the natAg(n, x) reactions induced by neutrons with the energies of 14–37 MeV

The natAg(n, xn)106m,g,104m,g,105gAg reaction cross-sections within the neutron energies of 14–37 MeV were determined by using an activation and off-line γ-ray spectrometric technique. The quasi-mono energetic neutron beams were produced from the 9Be(p, xn)9B reaction by using the proton beams of 25, 35, and 45 MeV at the Korean Institute of Radiological and Medical Sciences, Korea. Monte Carlo simulation code MCNPX was used to simulate the neutron energy spectra, whereas the theoretical cross-sections were calculated using the TALYS 1.8 code. The experimental and theoretical reaction cross-sections show similar trends from lower to higher neutron energy. The isomeric cross-section ratios of 104m,gAg and 106m,gAg for the natAg(n, xn) reactions were also obtained from the experimental values of present work and compared with the literature data.

Activation cross section and isomeric cross-section ratio for the (n,2n) reaction on 132,134Ba

Abstract Cross sections of the 132Ba(n,2n)131m,gBa and 134Ba(n,2n)133m,gBa reactions and their isomeric cross section ratios σm/σg have been measured by means of the activation technique at three neutron energies in the range 13−15 MeV. BaCO3 samples and Nb monitor foils were activated together to determine the reaction cross section and the incident neutron flux. The quasimonoenergetic neutrons beam were produced via the 3H(d,n)4He reaction at the Pd-300 Neutron Generator of the Chinese Academy of Engineering Physics (CAEP). The activities induced in the reaction products were measured using high−resolution γ ray spectroscopy. The pure cross section of the ground-state was derived from the absolute cross section of the metastable state and the residual nuclear decay analysis. Cross sections were also evaluated theoretically using the numerical nuclear model code, TALYS-1.8 with different level density options at neutron energies varying from the reaction threshold to 20 MeV. Results are discussed and compared with the corresponding literature.

Activation cross section and isomeric cross-section ratio for the 151Eu(n,α)148m,gPm process from threshold up to 20 MeV

The cross sections of 151Eu(n,α)148m,gPm reactions and their isomeric cross section ratio σm/σt have been measured at three neutron energies 13.5, 14.1, and 14.8 MeV by means of the activation technique, relative to the 27Al(n,α)24Na reaction reference cross section. The pure cross section of the ground-state was then derived from the absolute cross section of the metastable state and residual nuclear decay analysis. The cross sections were also estimated using the nuclear model code, TALYS-1.8 with different level density options at neutron energies varying from the reaction threshold to 20 MeV. Results are discussed and compared with the corresponding literature.

The excitation functions of 187Re(n,2n) 186m,gRe reactions

A new value for the emission probability of 137.144 keV γ-rays from 186gRe decay is recommended to be (9.47±0.03)/%. Using this value the measured cross sections for 187Re(n,2n)186mRe and 187Re(n,2n)186gRe reactions around 14 MeV are analyzed, and the cross section for 187Re(n,2n)186m+gRe reaction at 14.8 MeV is (2213±116) mb. The UNF code was adopted to calculate the cross sections for the 187Re(n,2n)186m+gRe reaction below 20 MeV, fitting to the value (2213±116) mb at 14.8 MeV using a set of optimum neutron optical potential parameters which were obtained based on the relevant experimental data of rhenium. The isomeric cross section ratio for the 187Re(n,2n)186m,gRe reaction was analyzed using the V-H method based on nuclear statistical theory. Combining these calculated results, the excitation functions for the 187Re(n,2n)186mRe and 187Re(n,2n)186gRe reactions were obtained. The obtained results are in good agreement with the available experimental data.

Izomerni vidnoshennya pereriziv v yadrakh 93,95Tc ta 95Nb

Izomerni vidnoshennya pereriziv v yadrakh 93,95Tc ta 95Nb

Interpretation and prediction of fast particle irradiation impact by data-containing codes.

The problem of interpretation, estimation and prediction of impacts of nature or artificial irradiation on various materials by modern nuclear reaction codes is discussed. Advanced data-containing codes EMPIRE and TALYS are considered. The yields of radioactive isotopes in high-energy p+(183)W collision are calculated to illustrate the potentialities of the codes for the declared purposes. The reliability of codes of such a type is treated. Measurements of isomeric cross-section ratios and comparison of these experimental results with the calculated ones are proposed as a promising test of the reliability.

Experimental study of incomplete fusion reactions in theO16+Te130system below 6 MeV/nucleon

Background: The measurement and analysis of excitation functions may be used as an important tool to understand incomplete fusion reaction dynamics.Purpose: Several studies have been carried out to study incomplete fusion reactions at low energies, but a clear picture of incomplete fusion reaction processes at energies below 6 MeV/nucleon has yet to emerge. Further, there is no theoretical model which may give a good representation of incomplete fusion processes.Method: Off-line $\ensuremath{\gamma}$-ray spectrometry has been used to measure the excitation functions in the ${}^{16}\text{O}+{}^{130}\text{Te}$ system at energies $\ensuremath{\approx}3$--6 MeV/nucleon.Results: Excitation functions for five reaction products populated via complete and/or incomplete fusion processes in the $^{16}\mathrm{O}$ + $^{130}\mathrm{Te}$ system have been measured. Measured cross-sections have been compared with the predictions of the statistical model code pace4. A significant enhancement in the measured excitation functions compared to theoretical predictions for $\ensuremath{\alpha}$-emitting channels has been observed and is attributed to incomplete fusion processes. The relative strength of incomplete fusion has been found to increase with projectile energy. In the case of the $^{133}\mathrm{Xe}$($3\ensuremath{\alpha}n$) channel, the isomeric cross-section ratios have been deduced and found to increase rapidly with beam energy, indicating the importance of imparted angular momentum. The angular momentum at different energies has also been calculated. The analysis of the data indicates that incomplete fusion is associated even for angular momentum values smaller than the critical angular momentum for complete fusion. The results have been discussed in terms of the $\ensuremath{\alpha}$-cluster structure of the projectile for various fusion reactions.Conclusions: It may be concluded that, apart from complete fusion, incomplete fusion processes are of greater importance even at energies as low as $\ensuremath{\approx}$3-6 MeV/nucleon, where fusion evaporation channels are expected to be dominant. The measured isomeric cross-section ratio for the dominant incomplete fusion channel is found to increase with energy. Analysis of the data indicates that the incomplete fusion contribution becomes significant even for values of imparted angular momentum $\ensuremath{\ell}l{\ensuremath{\ell}}_{\mathrm{critical}}$ also, contrary to SUMRULE model predictions.

Cross-sections of 45Sc(n, 2n)44m,gSc reaction from the reaction threshold to 20 MeV

Summary Cross sections of 45Sc(n, 2n)44m,g Sc reactions and their isomeric cross section ratios σ m /σ g have been measured at three neutron energies between 13.5 and 14.8 MeV using the activation technique. The pure cross section of the groundstate was then obtained by utilizing the absolute cross section of the metastable state and analysis methods of residual nuclear decay. The monoenergetic neutron beam was produced via the 3H(d, n)4He reaction. The cross sections were also estimated with the TALYS-1.2 nuclear model code using different level density options, at neutron energies varying from the reaction threshold to 20 MeV. Results are also discussed and compared with some corresponding values found in the literature.

STUDY OF ISOMERIC CROSS-SECTION RATIO AND PRE-EQUILIBRIUM FRACTION IN PROTON AND ALPHA PARTICLE INDUCED NUCLEAR REACTIONS ON 197Au

Excitation functions for the reactions 197 Au(p,n) 197g Hg and 197 Au(p,n) 197m Hg have been measured over the energy ranges from threshold up to 20 MeV using stacked foil activation technique. The isomeric cross-section ratio σm/(σm+σg) for the formation of 197g, m Hg was determined. The excitation functions and isomeric cross-section ratios were calculated for the reactions 197 Au(p,n) 197g,m Hg , 197 Au(p,2n) 196 Hg , 197 Au(p,3n) 195g,m Hg , 197 Au(p,4n) 194 Hg , 197 Au(p,5n) 193g,m Hg , 197 Au (α, n )200 Tl , 197 Au (α, 2n )199 Tl , 197 Au (α, 3n )198g,m Tl , 197 Au (α, 4n )197 Tl and 197 Au (α, 5n )196g,m Tl from reaction threshold up to 40 MeV for proton induced reactions and 80 MeV for alpha induced reactions. The results were compared with the theoretical cross-sections calculated by means of the code EMPIRE-II and with the available literature data, which makes use of the Hauser Feshbach model for the compound nuclear calculations and the exciton model for the pre-equilibrium emission part. The isomeric cross-section ratio is found to depend strongly on the relative spins of the isomeric and ground state, energy difference between the levels, presence of intermediate states and some dependence on decay modes and on the onset of pre-equilibrium emission.