The Experts below are selected from a list of 165 Experts worldwide ranked by ideXlab platform
J Kopecky - One of the best experts on this subject based on the ideXlab platform.
-
test of gamma ray strength functions in Nuclear reaction Model calculations
Physical Review C, 1990Co-Authors: J KopeckyAbstract:The impact of Models for {ital E}1 and {ital M}1 gamma-ray strength functions on the results of Nuclear Model calculations of total average radiation widths, radiative capture cross sections, and gamma-ray spectra has been studied. We considered strength functions that reproduce photoabsorption and/or average resonance data but significantly differ from each other at low gamma-ray energies. As the calculated quantities critically depend on the strength functions in this energy region, Model calculations can be used to test the low-energy behavior of strength functions. By analyzing the {sup 197}Au, {sup 143}Nd, {sup 105}Pd, and {sup 93}Nd neutron capture reactions we found strong evidence for a Model of the {ital E}1 strength function, which is characterized by the following properties: (i) an energy dependent spreading width of the underlying Lorentzian for the photoabsorption cross section and (ii) a nonzero, temperature dependent, limit as the transition energy tends to zero. This Model is founded in theoretical work by Zaretskij, Sirotkin, and Kadmenskij and represents a partial breakdown of Brink's hypothesis.
M. Al-abyad - One of the best experts on this subject based on the ideXlab platform.
-
Experimental study and Nuclear Model calculations of 3He-induced Nuclear reactions on zinc
European Physical Journal A, 2017Co-Authors: M. Al-abyad, Gehan Y. Mohamed, F. Ditrói, S. Takács, F. TárkányiAbstract:Excitation functions of 3He -induced Nuclear reactions on natural zinc were measured using the standard stacked-foil technique and high-resolution gamma-ray spectrometry. From their threshold energies up to 27MeV, the cross-sections for natZn (3He,xn) 69Ge, natZn(3He,xnp) 66,67,68Ga, and natZn(3He,x)62,65Zn reactions were measured. The Nuclear Model codes TALYS-1.6, EMPIRE-3.2 and ALICE-IPPE were used to describe the formation of these products. The present data were compared with the theoretical results and with the available experimental data. Integral yields for some important radioisotopes were determined.
-
Cross-section measurements and Nuclear Model calculation for proton induced Nuclear reaction on zirconium
2012Co-Authors: M. Al-abyad, F. Ditrói, S. Takács, F. Tárkányi, A. S Abdel-hamid, U. Seddik, I.i. BashterAbstract:Proton induced Nuclear reactions were measured with stacked-foil technique on natural zirconium targets up to 16.7 MeV. Excitation functions were measured for the production of Nb and Y. Cumulative cross-section, thick target yields and activation functions were deduced and compared with the available experimental data, as well as with the Nuclear Models codes; ALICE-IPPE, EMPIRE and TALYS. The integral yields for thick targets were deduced from the measured excitation function of the produced radionuclides. & 2011 Elsevier Ltd. All rights reserved.
-
Cross Section Measurements of Proton Induced Reactions on 55Mn and Comparison of Experimental Results with Di erent Nuclear Model Calculations
Journal of the Korean Physical Society, 2011Co-Authors: B. Scholten, M. Al-abyad, S.m. Qaim, I. Spahn, S. Spellerberg, H. H. Coenen, M. N. H. ComsanAbstract:Excitation functions of the reactions Mn-55(p,n)Fe-55, Mn-55(p,x)Mn-54 and Mn-55(p,x)Cr-51 were measured from their respective thresholds up to 18 MeV in the first case and up to 45 MeV in the latter two cases, using the conventional stacked-foil technique. The radioactivity of Fe-55 was determined via high resolution X-ray spectrometry; both non-destructively and after radiochemical separation, and of the other radionuclides via high resolution gamma-ray spectrometry. Nuclear Model calculations were performed using the codes ALICE-IPPE, EMPIRE and TALYS. In some cases good agreement was found between the experimental and theoretical data while in others considerable deviations were observed. From the experimental data the integral yields of the three investigated radionuclides were calculated
-
Cross-section measurements and Nuclear Model calculation for proton induced Nuclear reaction on zirconium
Applied Radiation and Isotopes, 2011Co-Authors: M. Al-abyad, F. Ditrói, S. Takács, F. Tárkányi, A. S Abdel-hamid, U. Seddik, I.i. BashterAbstract:Abstract Proton induced Nuclear reactions were measured with stacked-foil technique on natural zirconium targets up to 16.7 MeV. Excitation functions were measured for the production of 90,92m,95m,95g,96 Nb and 88 Y. Cumulative cross-section, thick target yields and activation functions were deduced and compared with the available experimental data, as well as with the Nuclear Models codes; ALICE-IPPE, EMPIRE and TALYS. The integral yields for thick targets were deduced from the measured excitation function of the produced radionuclides.
-
Experimental studies and Nuclear Model calculations on proton induced reactions on manganese up to 45 MeV with reference to production of 55Fe, 54Mn and 51Cr
Applied Radiation and Isotopes, 2010Co-Authors: M. Al-abyad, I. Spahn, S.m. QaimAbstract:Abstract Excitation functions of the reactions 55 Mn(p,n) 55 Fe, 55 Mn(p,x) 54 Mn and 55 Mn(p,x) 51 Cr were measured from their respective thresholds up to 18 MeV in the first case and up to 45 MeV in the latter two cases, using the conventional stacked-foil technique. The radioactivity of 55 Fe was determined via high resolution X-ray spectrometry and of other radionuclides via high resolution γ-ray spectrometry. Nuclear Model calculations were performed using the codes ALICE-IPPE, EMPIRE and TALYS. In some cases, good agreement was found between the experimental and theoretical data while in others considerable deviations were observed. From the experimental data the expected integral yields of the three investigated radionuclides were calculated.
Syed M. Qaim - One of the best experts on this subject based on the ideXlab platform.
-
Nuclear Model analysis of excitation functions of α-particle induced reactions on In and Cd up to 60 MeV with relevance to the production of high specific activity 117mSn
Applied Radiation and Isotopes, 2017Co-Authors: M. N. Aslam, K. Zubia, Syed M. QaimAbstract:Abstract Excitation functions were calculated for the α-particle induced reactions 115In(α,x)117mSn, 114Cd(α,n)117mSn, 116Cd(α,3n)117mSn and natCd(α,x)117mSn to analyse the production of the medically important 117mSn (T½ = 13.6 d). For calculations three Nuclear Model codes (i.e. TALYS, EMPIRE and ALICE-IPPE) were used and the results were compared with the available experimental data. For the most important reaction, 116Cd(α,3n)117mSn, evaluated data are presented. The yield and radionuclidic purity of 117mSn from each reaction are discussed.
-
Nuclear Model analysis of excitation functions of proton, deuteron and α-particle induced reactions on nickel isotopes for production of the medically interesting copper-61.
Applied Radiation and Isotopes, 2014Co-Authors: M. N. Aslam, Syed M. QaimAbstract:Abstract Excitation functions of the 61Ni(p,n)61Cu, 62Ni(p,2n)61Cu, 60Ni(d,n)61Cu and 58Ni(α,p)61Cu reactions were analyzed with respect to the production of 61Cu (T½=3.33 h), a promising radionuclide for PET imaging. The Nuclear Model codes EMPIRE and TALYS reproduced the experimental data of all reactions well, except those for the (d,n) process. The fitted excitation functions were employed to calculate the integral yield of 61Cu in all reactions. The amounts of the possible impurities 62Cu and 60Cu were assessed. A validation of the evaluated (p,xn) data was attempted.
-
Experimental studies and Nuclear Model calculations on (p, xn) and (p, pxn) reactions on 85Rb from their thresholds up to 100 MeV
Radiochimica Acta, 2004Co-Authors: S. Kastleiner, Yu.n. Shubin, Francois M. Nortier, T.n. Van Der Walt, Syed M. QaimAbstract:Summary. Excitation functions were measured by the stack-ed-foil technique for the reactions 85 Rb( p, pxn ) 84m , g , 83 , 82m , 81 Rbfrom their thresholds up to 100 MeV. Nuclear Model cal-culations were performed using the code ALICE-IPPE bothon ( p,xn ) reactions reported earlier and ( p, pxn ) reactionsdescribed here. The experimental excitation curves and theresults of Nuclear Model calculations were found to be quali-tatively in agreement. With the exception of the ( p,n ) reactionabove 40MeV, the theory appears to reproduce all the experi-mental data within deviations of about 50%. The cross sectionratios for the isomeric pairs 85m,g Sr and 84m,g Rb are discussedqualitatively in terms of the spins of the states involved andthe increasing projectile energy. 1. Introduction A knowledge of excitation functions of charged particle in-duced reactions is of considerable significance for definingoptimum conditions for production of some medically im-portant radionuclides at accelerators as well as for testingNuclear Models. Of particular interest is the intermediate en-ergy range of 30 to 100 MeV where, for many target nuclei,the experimental data base is still rather weak.The excitation functions of proton induced reactions on
S.m. Qaim - One of the best experts on this subject based on the ideXlab platform.
-
Nuclear Model analysis of excitation functions of proton induced reactions on 86Sr, 88Sr and natZr: Evaluation of production routes of 86Y
Applied Radiation and Isotopes, 2015Co-Authors: H. Zaneb, Mazhar Hussain, N. Amjed, S.m. QaimAbstract:Abstract The proton induced Nuclear reactions on 86Sr, 88Sr and natZr were investigated for the production of 86Y. The literature data were compared with the results of Nuclear Model calculations using the codes ALICE-IPPE, TALYS 1.6 and EMPIRE 3.2. The thick target yields of 86Y were calculated from the recommended excitation functions. Analysis of radioyttrium impurities was also performed. A comparison of the various production routes showed that for medical applications of 86Y, the reaction 86Sr(p,n)86Y is the method of choice, which gives efficient yield with minimum impurities.
-
Cross Section Measurements of Proton Induced Reactions on 55Mn and Comparison of Experimental Results with Di erent Nuclear Model Calculations
Journal of the Korean Physical Society, 2011Co-Authors: B. Scholten, M. Al-abyad, S.m. Qaim, I. Spahn, S. Spellerberg, H. H. Coenen, M. N. H. ComsanAbstract:Excitation functions of the reactions Mn-55(p,n)Fe-55, Mn-55(p,x)Mn-54 and Mn-55(p,x)Cr-51 were measured from their respective thresholds up to 18 MeV in the first case and up to 45 MeV in the latter two cases, using the conventional stacked-foil technique. The radioactivity of Fe-55 was determined via high resolution X-ray spectrometry; both non-destructively and after radiochemical separation, and of the other radionuclides via high resolution gamma-ray spectrometry. Nuclear Model calculations were performed using the codes ALICE-IPPE, EMPIRE and TALYS. In some cases good agreement was found between the experimental and theoretical data while in others considerable deviations were observed. From the experimental data the integral yields of the three investigated radionuclides were calculated
-
Experimental studies and Nuclear Model calculations on proton induced reactions on manganese up to 45 MeV with reference to production of 55Fe, 54Mn and 51Cr
Applied Radiation and Isotopes, 2010Co-Authors: M. Al-abyad, I. Spahn, S.m. QaimAbstract:Abstract Excitation functions of the reactions 55 Mn(p,n) 55 Fe, 55 Mn(p,x) 54 Mn and 55 Mn(p,x) 51 Cr were measured from their respective thresholds up to 18 MeV in the first case and up to 45 MeV in the latter two cases, using the conventional stacked-foil technique. The radioactivity of 55 Fe was determined via high resolution X-ray spectrometry and of other radionuclides via high resolution γ-ray spectrometry. Nuclear Model calculations were performed using the codes ALICE-IPPE, EMPIRE and TALYS. In some cases, good agreement was found between the experimental and theoretical data while in others considerable deviations were observed. From the experimental data the expected integral yields of the three investigated radionuclides were calculated.
-
Radiochemical determination of Nuclear data for theory and applications
Journal of Radioanalytical and Nuclear Chemistry, 2010Co-Authors: S.m. QaimAbstract:A vast knowledge of Nuclear data is available and is grouped under three headings, namely, Nuclear structure, Nuclear decay and Nuclear reaction data. Still newer aspects are under continuous investigation. Data measurements are done using a large number of techniques, including the radiochemical method, which has been extensively worked out at Jülich. This method entails preparation of high-quality sample for irradiation, isolation of the desired radioactive product from the strong matrix activity, and preparation of thin source suitable for accurate measurement of the radioactivity. It is especially useful for fundamental studies on light complex particle emission reactions and formation of low-lying isomeric states, both of which are rather difficult to describe by Nuclear Model calculations. The neutron induced reaction cross section data are of practical application in fusion reactor technology, particularly for calculations on tritium breeding, gas production in structural materials and activation of reactor components. The charged particle induced reaction cross section data, on the other hand, are of significance in medicine, especially for developing new production routes of novel positron emitters and therapeutic radionuclides at a cyclotron. Both neutron and charged particle data also find application in radiation therapy. A brief overview of advances made in all those areas is given, with major emphasis on Nuclear reaction cross section data.
M.b. Chadwick - One of the best experts on this subject based on the ideXlab platform.
-
Improvements to the Nuclear Model code GNASH for cross section calculations at higher energies
1994Co-Authors: P.g. Young, M.b. ChadwickAbstract:The Nuclear Model code GNASH, which in the past has been used predominantly for incident particle energies below 20 MeV, has been modified extensively for calculations at higher energies. The Model extensions and improvements are described in this paper, and their significance is illustrated by comparing calculations with experimental data for incident energies up to 160 MeV.
-
Use of the Nuclear Model code GNASH to calculate cross section data at energies up to 100 MeV
1992Co-Authors: P.g. Young, M.b. Chadwick, M. BosoianAbstract:The Nuclear theory code GNASH has been used to calculate Nuclear data for incident neutrons, protons, and deuterons at energies up to 100 MeV. Several Nuclear Models and theories are important in the 10--100 MeV energy range, including Hauser-Feshbach statistical theory, spherical and deformed optical Model, preequilibrium theory, Nuclear level densities, fission theory, and direct reaction theory. In this paper we summarize general features of the Models in GNASH and describe the methodology utilized to determine relevant Model parameters. We illustrate the significance of several of the Models and include comparisons with experimental data for certain target materials that are important in applications.
-
Comprehensive Nuclear Model calculations: Introduction to the theory and use of the GNASH code
1992Co-Authors: P.g. Young, E.d Arthur, M.b. ChadwickAbstract:A user's manual describing the theory and operation of the GNASH Nuclear reaction computer code is presented. This work is based on a series of lectures describing the statistical Hauser-Feshbach plus preequilibrium version of the code with full angular momentum conservation. This version is expected to be most applicable for incident particle energies between 1 key and 50 MeV. General features of the code, the Nuclear Models that are utilized, input parameters needed to perform calculations, and the output quantities from typical problems are described in detail. The computational structure of the code and the subroutines and functions that are called are summarized as well. Two detailed examples are considered: 14-MeV neutrons incident on {sup 93}Nb and 12-MeV neutrons incident on {sup 238}U. The former example illustrates a typical calculation aimed at determining neutron, proton, and alpha emission spectra from 14-MeV reactions, and the latter example demonstrates use of the fission Model in GNASH.
