arXiv subjects

A. V. Ignatyuk

Publications and source records attributed to A. V. Ignatyuk.

34 records · Page 2Linked to original sources

arXiv2014

Activation cross-sections of deuteron induced nuclear reactions on neodymium up to 50 MeV

In the frame of a systematic study of activation cross sections of deuteron induced nuclear reactions on rare earths, the reactions on neodymium for production of therapeutic radionuclides were measured for the first time. The excitation functions of the natNd(d,x) 151,150,149,148m,148g,146,144,143Pm, 149,147,139mNd, 142Pr and 139gCe nuclear reactions were assessed by using the stacked foil activation technique and high resolution $γ@-spectrometry. The experimental excitation functions were compared to the theoretical predictions calculated with the modified model codes ALICE-IPPE-D and EMPIRE-II-D and with the data in the TENDL-2012 library based on latest version of the TALYS code. The application of the data in the field of medical isotope production and nuclear reaction theory is discussed.

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arXiv2014

Activation cross-sections of long lived products of deuteron induced nuclear reactions on dysprosium up to 50 MeV

Activation cross-sections for production of 162m,161,155Ho,165,159,157,155Dy and 161,160,156,155Tb radionuclides in deuteron induced nuclear reactions on elemental dysprosium were measured up to 50 MeV for practical application and the test of the predictive power of nuclear reaction model codes. A stacked-foil irradiation technique and off-line gamma-ray spectrometry were used to determine the activities. No earlier cross-section data were found in the literature. The experimental data are compared with the predictions of the ALICE-D, EMPIRE-D and TALYS codes. Integral production yields were calculated from the fitted experimental data.

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arXiv2013

Activation cross-sections of deuteron induced reactions on natGd up to 50 MeV

Activation cross-sections are presented for the first time for natGd(d,xn)161,160,156(m+), 154,154m1,154m2,153,152(m+),151(m+)Tb, natGd(d,x)159,153,151Gd and natGd(d,x)156Eu reactions from their respective thresholds up to 50 MeV. The cross-sections were measured by the stacked-foil irradiation technique and by using high resolution gamma-ray spectrometry. The measured values were compared with the results of theoretical models calculated by the computer codes ALICE-D, EMPIRE-D and TALYS (data from TENDL library). Integral yields of the reaction products were deduced from the excitation functions.

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arXiv2013

Activation cross-sections of longer-lived products of proton induced nuclear reactions on dysprosium up to 36 MeV

Activation cross-sections of longer-lived products of proton induced nuclear reactions on dysprosium were measured up to 36 MeV by using stacked foil irradiation technique and gamma-spectrometry. We report for the first time experimental cross-sections for the formation of the radionuclides 162mHo, 161Ho, 159Ho, 159Dy, 157Dy, 155Dy, 161Tb, 160Tb, 156Tb and 155Tb. The experimental data were compared with the results of cross-section calculations of the ALICE and EMPIRE nuclear model codes and of the TALYS nuclear reaction model code as listed in the on-line libraries TENDL 2011 and TENDL 2012.

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arXiv2013

Excitation Function of the nat-Ta(p,x)178m2-Hf Reaction

178m2-Hf is an extremely interesting isomeric state due to its potential energy capacity level. One possible way to obtain it is by irradiation of a nat-Ta sample with a high-current proton accelerator. Up to now, there was no information in the international experimental nuclear data base (EXFOR) for this reaction. Irradiations of nat-Ta samples performed for other purposes provide an opportunity to address this question. This paper presents the 172m2-Hf independent production cross-sections determined by gamma-ray spectrometry. The nat-Ta(p,x)172m2-Hf excitation function is studied in the 20-3500 MeV energy range. Comparisons with results by several nuclear models (ISABEL, Bertini, INCL4.5+ABLA07, PHITS, CASCADE07, and CEM03.02) used as event-generators in modern transport codes are also reported. However, since such models are generally not able to separately predict ground and isomeric states of reaction products, only 178-Hf independent and cumulative cross-section data are compared.

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arXiv2013

Cross-section measurement of some deuteron induced reactions on $^{160}$Gd for possible production of the therapeutic radionuclide $^{161}$Tb

The radionuclide 161Tb (T1/2=6.89 d) is potentially important for internal radiotherapy. It is generally produced through the 160Gd(n,γ)161Gd - 161Tb route at research reactors. In this work the possibility of its production at a cyclotron was investigated. Determination of the excitation function of the 160Gd(d,x)161Tb production route and that of the disturbing 160Gd(d,2n)160Tb side reaction was done over the deuteron energy range up to 50 MeV using the stacked-foil technique and high-resolution gamma-ray spectrometry. A comparison of this production route with the established (n,γ) reaction at a nuclear reactor is made.

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arXiv2013

Activation cross-sections of longer lived radioisotopes of deuteron induced nuclear reactions on terbium up to 50 MeV

Experimental cross-sections are presented for the first time for the 159Tb(d,xn)155,157,159Dy, 155,156,160Tb and 153Gd nuclear reactions up to 50 MeV. The experimental data are compared with theoretical predictions of the ALICE, EMPIRE and TALYS nuclear reaction codes. Integral thick-target yields are also derived for the reaction products that have practical applications.

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arXiv2013

Activation cross-sections of longer lived products of deuteron induced nuclear reactions on ytterbium up to 40 MeV

In the frame of a systematic study of the activation cross-sections of the deuteron induced nuclear reactions, excitation functions of the natYb(d,xn)177,173,172mg,171mg,170,169Lu, natYb(d,x)175,169Yb and natYb(d,x)173,172,168,167,165Tm reactions are studied up to 40 MeV, a few of them for the first time. Cross-sections were measured with the activation method using a stacked foil irradiation technique and high resolution gamma-ray spectrometry. The experimental data are analyzed and compared to the results of the theoretical model codes ALICE-IPPE, EMPIRE-II and TALYS. From the measured cross-section data integral production yields were calculated. Applications of the new cross-sections are discussed.

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arXiv2013

Investigation of activation cross-section data of proton induced nuclear reactions on rhenium

In the frame of systematic investigations of activation cross-section data for different applications the excitation functions of natRe(p,x)185Os, 183mOs, 183gOs, 182Os, 181mOs, 186gRe, 184mRe, 184gRe, 183Re, 182mRe, 182gRe and 181gRe reactions were measured up to 70 MeV. The data for the natRe(p,x)183mOs, 183gOs, 182Os, 181gOs,186gRe, 184mRe,182mRe, 182gRe, 181Re reactions are reported for the first time. Activation method, stacked foil irradiation technique and gamma-spectroscopy for activity detection were used. The experimental data were compared with predictions of three theoretical codes. From the measured cross-section thick target integral yields were also calculated and presented.

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arXiv2013

Investigation of production routes for the 161Ho Auger-electron emitting radiolanthanide, a candidate for therapy

The radiolanthanide 161Ho (2.48 h) is a promising Auger-electron emitter for internal radiotherapy that can be produced with particle accelerators. The excitation functions of the natDy(p,xn)161Ho and natDy(d,x)161Ho reactions were measured up to 40 and 50 MeV respectively by using the stacked foil activation method and gamma-ray spectrometry. The experimental data were compared with results of the TALYS code available in the TENDL 2011 library [1]. The main parameters of different production routes are discussed.

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arXiv2013

Investigation of activation cross-sections of proton induced nuclear reactions on natTl up to 42 MeV: review, new data and evaluation

Cross-sections of proton induced nuclear reactions on natural thallium have been studied for investigation of the production of the medical important 201Tl diagnostic radioisotope. The excitation functions of 204mPb, 203Pb, 202mPb, 201Pb, 200Pb, 199Pb, 202Tl (direct, cumulative), 201Tl (direct, cumulative), 200Tl(direct), and 203Hg were measured up to 42 MeV proton energy by stacked foil technique and activation method. The experimental data were compared with the critically analyzed experimental data in the literature, with the IAEA recommended data and with the results of model calculations by using the ALICE-IPPE, EMPIRE-II and TALYS codes.

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arXiv2013

Activation cross-sections of deuteron induced nuclear reactions on rhenium up to 40 MeV

As a part of a thorough work of excitation functions of deuteron induced reactions, experimental cross-sections of ^{185,183m,183g,182}Os and ^{188,186,184m,184g,183}Re activation products on natRe were measured up to 40 MeV for the first time with the activation method using a stacked foil irradiation technique and high resolution γ-spectrometry. Comparison with the former results of other laboratories and with the predictions of the ALICE-IPPE and EMPIRE-3 model codes, modified for improved calculations for deuteron reactions, and with data in the TENDL-2011 library are also presented. Thick target yields were given deduced from our experimental cross-sections and compared with the few literature values. For practical applications (thin layer activation) also activity versus depth distributions were calculated for selected isotopes.

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arXiv2011

Verification of high-energy transport codes on the basis of activation data

Nuclide production cross sections measured at ITEP for the targets of nat-Cr, 56-Fe, nat-Ni, 93-Nb, 181-Ta, nat-W, nat-Pb, 209-Bi irradiated by protons with energies from 40 to 2600 MeV were used to estimate the predictive accuracy of several popular high-energy transport codes. A general agreement of the ITEP data with the data obtained by other groups, including the numerous GSI data measured by the inverse kinematics method was found. Simulations of the measured data were performed with the MCNPX (Bertini and ISABEL options), CEM03.02, INCL4.2+ABLA, INCL4.5+ABLA07, PHITS, and CASCADE.07 codes. Deviation factors between the calculated and experimental cross sections have been estimated for each target and for the whole energy range covered by our measurements. Two-dimensional diagrams of deviation factor values were produced for estimating the predictive power of every code for intermediate, not measured masses of nuclei-targets and bombarding energies of protons. Further improvements of all tested here codes are recommended. In addition, new measurements at ITEP of nuclide yields from a 208-Pb target irradiated by 500 MeV protons are presented. A good agreement between these new data and the GSI measurements obtained by the inverse kinematics method was found

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arXiv2008

Cross-sections for nuclide production in 56Fe target irradiated by 300, 500,750, 1000, 1500, and 2600 MeV protons compared with data on hydrogen target irradiation by 300, 500, 750, 1000, and 1500 MeV/nucleon 56Fe ions

Cross-sections for radioactive nuclide production in 56Fe(p,x) reactions at 300, 500, 750, 1000, 1500, and 2600 MeV were measured using the ITEP U-10 proton accelerator. In total, 221 independent and cumulative yields of products of half-lives from 6.6 min to 312 days have been obtained via the direct-spectrometry method. The measured data have been compared with the experimental data obtained elsewhere by the direct and inverse kinematics methods and with calculations by 15 codes, namely: MCNPX (INCL, CEM2k, BERTINI, ISABEL), LAHET (BERTINI, ISABEL), CEM03 (.01, .G1, .S1), LAQGSM03 (.01, .G1, >.S1), CASCADE-2004, LAHETO, and BRIEFF. Most of our data are in a good agreement with the inverse kinematics results and disprove the results of some earlier activation measurements that were quite different from the inverse kinematics measurements. The most significant calculation-to-experiment differences are observed in the yields of the A<30 light nuclei, indicating that further improvements in nuclear reaction models are needed, and pointing out as well to a necessity of more complete measurements of such reactions.

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arXiv2007

Residual nuclide formation in 206,207,208,nat-Pb and 209-Bi induced by 0.04-2.6 GeV Protons as well as in 56-Fe induced by 0.3-2.6 GeV Protons

5972 independent and cumulative yields of radioactive residuals nuclei have been measured in 55 thin 206,207,208,nat-Pb and 209-Bi targets irradiated by 0.04, 0.07, 0.10, 0.15, 0.25, 0.6, 0.8, 1.2, 1.4, 1.6, and 2.6 GeV protons. Besides, 219 yields have been measured in 0.3, 0.5, 0.75, 1.0, 1.5, and 2.6 GeV proton-irradiated 56-Fe target. The protons were extracted from the ITEP U-10 synchrotron. The measured data are compared with experimental results obtained elsewhere and with theoretical calculations by LAHET, MCNPX, CEM03, LAQGSM03, CASCADE, CASCADO, and LAHETO codes. The predictive power was found to be different for each of the codes tested, but was satisfactory on the whole in the case of spallation products. At the same time, none of the codes can de-scribe well the product yields throughout the whole product mass range, and all codes must be further improved.

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arXiv2003

Complex nuclear-structure phenomena revealed from the nuclide production in fragmentation reactions

Complex structural effects in the nuclide production from the projectile fragmentation of 1 A GeV 238U nuclei in a titanium target are reported. The structure seems to be insensitive to the excitation energy induced in the reaction. This is in contrast to the prominent structural features found in nuclear fission and in transfer reactions, which gradually disappear with increasing excitation energy. Using the statistical model of nuclear reactions, relations to structural effects in nuclear binding and in the nuclear level density are demonstrated.

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