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Sample records for 243am 209bi natw

  1. Preparation of tracer 239Np from 243Am

    The aim of this work is the preparation of tracer 239Np from 243Am by extraction chromatography as a separation method that can be used as a tracer to determine the radiochemical yield of 237Np in the analysis of environmental samples. (authors)

  2. Radiationless transition probabilities in muonic 209Bi

    The probability for non-radiative (n.r.) excitations in muonic 209Bi was determined from a (μ-, γγ)-measurement by comparing the intensities of muonic X-ray transitions in single and coincidence spectra. The values of Pn.r.(3p→1s)=(17.9±2.0)% and Pn.r.(3d→1s)=(3.0±2.2)% were measured for the first time. The strength of the n.r. decay of the 2p-level was found to be (4.2±2.2)%. The n.r. transition probabilities of two subcomplexes of the (2p→1s)-transition leading to different mean excitation energies are (3.2±1.8)% and (5.0±2.0)%, respectively. (orig.)

  3. Fission dynamics study in 243Am and 254Fm

    Banerjee, K.; Ghosh, T. K.; Roy, P.; Bhattacharya, S.; Chaudhuri, A.; Bhattacharya, C.; Pandey, R.; Kundu, S.; Mukherjee, G.; Rana, T. K.; Meena, J. K.; Mohanto, G.; Dubey, R.; Saneesh, N.; Sugathan, P.; Guin, R.; Das, S.; Bhattacharya, P.

    2016-06-01

    Fission fragment mass distributions in the reactions 11B + 232Th and 11B + 243Am were measured in an energy range around the barrier. No sudden change in the width of the mass distribution as a function of center-of-mass energy was observed at near-barrier energies, indicating no quasifission transition in the near-barrier energies. Interestingly, the previous measurements of fission fragment angular anisotropies for the same systems showed significant departure from the statistical saddle-point model predictions at near-barrier energies, indicating the presence of nonequilibrium fission processes.

  4. Multinucleon photonuclear reactions on {sup 209}Bi: Experiment and evaluation

    Belyshev, S.S.; Kurilik, A.S. [Lomonosov Moscow State University, Department of Physics, Moscow (Russian Federation); Filipescu, D.M.; Tesileanu, O. [Extreme Light Infrastructure - Nuclear Physics/Horia Hulubei National Institute for R and D in Physics and Nuclear Engineering, Bucharest-Magurele (Romania); Gheoghe, I. [Extreme Light Infrastructure - Nuclear Physics/Horia Hulubei National Institute for R and D in Physics and Nuclear Engineering, Bucharest-Magurele (Romania); University of Bucharest, Faculty of Physics, Bucharest-Magurele (Romania); Ishkhanov, B.S. [Lomonosov Moscow State University, Department of Physics, Moscow (Russian Federation); Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow (Russian Federation); Khankin, V.V.; Kuznetsov, A.A.; Orlin, V.N.; Peskov, N.N.; Stopani, K.A.; Varlamov, V.V. [Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow (Russian Federation)

    2015-06-15

    Photon activation technique using bremsstrahlug with end-point energy 55.6 MeV is used to induce photonuclear reactions in a {sup 209}Bi target. Absolute yields and integrated cross sections of multiparticle reactions (γ, 2n-6n), (γ, 4n1p), and (γ, 5n1p) are obtained. The results are compared to predictions of statistical models using systematical and microscopic description of photoabsorption and to the result of evaluation of the partial photoneutron reaction cross sections. Based on a comparison with existing experimental photoneutron cross sections and model calculations, we make a conclusion that neutron multiplicity assignment in available photoneutron cross sections on {sup 209}Bi can be corrected and evaluated cross sections of (γ, 1n) and (γ, 2n) are obtained that are in an agreement with the obtained experimental results. (orig.)

  5. Preparation and high intensity heavy ion irradiation tests of intermetallic 243Am/Pd targets

    Previously reported preparation method for Pd-based intermetallic targets (Usoltsev, et al., 2012) [1] has been successfully applied for producing two stationary 243Am/Pd targets. Both targets have been irradiated at the U-400 cyclotron at Flerov Laboratory of Nuclear Reactions Dubna (Russian Federation) using high intensity beams (up to 0.83 μApart) of 48Ca18+. Alpha-particle spectroscopy and light microscopy allowed for a comprehensive characterization of the intermetallic targets before and after irradiation. A natNd/Pd intermetallic target and a solely electroplated 243Am/Ti target were similarly investigated for comparison

  6. Evaluation and calculation of photonuclear reaction data for 209Bi below 30 MeV

    Based on available experimental data of neutron and photonuclear reaction, both neutron optical potential parameter and giant resonance parameters of gamma for 209Bi were obtained. The photonuclear reaction data for 209Bi were calculated, compared with experimental data and recommended below 30 MeV

  7. Measurements of neutron cross section of the {sup 243}Am(n,{gamma}){sup 244}Am reaction

    Hatsukawa, Yuichi; Shinohara, Nobuo; Hata, Kentaro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    The effective thermal neutron cross section of {sup 243}Am(n,{gamma}){sup 244}Am reaction was measured by the activation method. Highly-purified {sup 243}Am target was irradiated in an aluminum capsule by using a research reactor JRR-3M. The tentative effective thermal neutron cross sections are 3.92 b, and 84.44 b for the production of {sup 244g}Am and {sup 244m}Am, respectively. (author)

  8. Pion-Induced Fission of 209Bi and 119Sn:. Measurements, Calculations, Analyses and Comparison

    Rana, Mukhtar Ahmed; Sher, Gul; Manzoor, Shahid; Shehzad, M. I.

    Cross-sections for the π--induced fission of 209Bi and 119Sn have been measured using the most sensitive CR-39 solid-state nuclear track detector. In experiments, target-detector stacks were exposed to negative pions of energy 500, 672, 1068, and 1665 MeV at the Brookhaven National Laboratory, USA. An important aspect of the present paper is the comparison of pion-induced fission fragment spectra of above mentioned nuclei with the spontaneous fission fragment spectra of 252Cf. This comparison is made in terms of fission fragment track lengths in the CR-39 detectors. Measurement results are compared with calculations of Monte Carlo and statistical weight functions methods using the computer code CEM95. Agreement between measurements and calculations is fairly good for 209Bi target nuclei whereas it is indigent for the case of 119Sn. The possibilities of the trustworthy calculations, using the computer code CEM95, comparable with measurements of pion-induced fission in intermediate and heavy nuclei are explored by employing various systematics available in the code. Energy dependence of pion-induced fission in 119Sn and 209Bi is analyzed employing a newly defined parameter geometric-size-normalized fission cross-section (χfg). It is found that the collective nuclear excitations, which may lead to fission, become more probable for both 209Bi and 119Sn nuclei with increasing energy of negative pions from 500 to 1665 MeV.

  9. Measurement and analysis of the $^{243}$Am neutron capture cross section at the n_TOF facility at CERN

    Mendoza, E; Guerrero, C; Berthoumieux, E; Abbondanno, U; Aerts, G; Alvarez-Velarde, F; Andriamonje, S; Andrzejewski, J; Assimakopoulos, P; Audouin, L; Badurek, G; Balibrea, J; Baumann, P; Becvar, F; Belloni, F; Calvino, F; Calviani, M; Capote, R; Carrapico, C; Carrillo de Albornoz, A; Cennini, P; Chepel, V; Chiaveri, E; Colonna, N; Cortes, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillmann, I; Dolfini, R; Domingo-Pardo, C; Dridi, W; Duran, I; Eleftheriadis, C; Ferrant†, L; Ferrari, A; Ferreira-Marques, R; Fitzpatrick, L; Frais-Koelbl, H; Fujii, K; Furman, W; Goncalves, I; Gonz alez-Romero, E; Goverdovski, A; Gramegna, F; Griesmayer, E; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martinez, A; Igashira, M; Isaev, S; Jericha, E; Kappeler, F; Kadi, Y; Karadimos, D; Karamanis, D; Ketlerov, V; Kerveno, M; Koehler, P; Konovalov, V; Kossionides, E; Krticka, M; Lampoudis, C; Leeb, H; Lindote, A; Lopes, I; Lossito, R; Lozano, M; Lukic, S; Marganiec, J; Marques, L; Marrone, S; Martınez, T; Massimi, C; Mastinu, P; Mengoni, A; Milazzo, P M; Moreau, C; Mosconi, M; Neves, F; Oberhummer, H; O’Brien, S; Oshima, M; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Paradela, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Pigni, M T; Plag, R; Plompen, A; Plukis, A; Poch, A; Praena, J; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, C; Rudolf, G; Rullhusen, P; Salgado, J; Santos, C; Sarchiapone, L; Savvidis, I; Stephan, C; Tagliente, G; Tain, J L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarin, D; Vicente, M C; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wendler, H; Wiescher, M; Wisshak, K

    2014-01-01

    Background:The design of new nuclear reactors and transmutation devices requires to reduce the present neutron cross section uncertainties of minor actinides. Purpose: Reduce the $^{243}$Am(n,$\\gamma$) cross section uncertainty. Method: The $^{243}$Am(n,$\\gamma$) cross section has been measured at the n_TOF facility at CERN with a BaF$_{2}$ Total Absorption Calorimeter, in the energy range between 0.7 eV and 2.5 keV. Results: The $^{243}$Am(n,$\\gamma$) cross section has been successfully measured in the mentioned energy range. The resolved resonance region has been extended from 250 eV up to 400 eV. In the unresolved resonance region our results are compatible with one of the two incompatible capture data sets available below 2.5 keV. The data available in EXFOR and in the literature has been used to perform a simple analysis above 2.5 keV. Conclusions: The results of this measurement contribute to reduce the $^{243}$Am(n,$\\gamma$) cross section uncertainty and suggest that this cross section is underestimate...

  10. High-energy neutron transport file for the 209Bi isotope

    The simulation of the nuclear processes, occurring in media irradiated with high-energy particles, promote the elaboration of high-energy transport files. These files being used in versatile computer codes, such as MCNP, allow to simulate with high accuracy particle transport. High-energy transport files are very important for the investigation of accelerator-driven systems. The detailed description of the methods and codes used for the elaboration of the file for 209Bi is presented in this paper. (orig.)

  11. Re-evaluation of neutron nuclear data for 242mAm, 243Am, 99Tc and140Ce

    The evaluated nuclear data given in JENDL-3.2 were compared with other evaluated data sets and available experimental data, for important minor actinides of 242mAm and 243Am, and fission product nuclides of 99Tc and 140Ce. Since problems were found as a result of the comparison, the data of JENDL-3.2 were improved for these nuclides. It was found that the evaluated data of Maslov et al. were superior to the others. They were adopted for 242mAm and 243Am after further improvements. For 99Tc and 140Ce, resonance parameters and optical model parameters were improved. The cross sections of these two nuclides in the smooth part were re-calculated. The present results were given in the neutron energy range from 10-5 eV to 20 MeV in the ENDF-6 format, and adopted to JENDL-3.3. (author)

  12. Competence of alpha spectrometry analysis algorithms used to resolve the 241Am and 243Am alpha peak overlap

    Five alpha spectrometry analysis algorithms were evaluated for their ability to resolve the 241Am and 243Am peak overlap present under typical low-level counting conditions. The major factors affecting the performance of the algorithms were identified using design-of-experiment combined with statistical analysis of the results. The study showed that the accuracy of the 241Am/243Am ratios calculated by the algorithms depends greatly on the degree of peak deformation and tailing. Despite the improved data quality obtained using an algorithm that may include peak addition and tail estimation, the accurate determination of 241Am by alpha spectrometry relies primarily on reduction of peak overlap rather than on algorithm selection

  13. The influence of impurities for cross section measurement of {sup 241,243}Am(n,f) reactions

    Kai, Tetsuya; Kobayashi, Katsuhei; Yamamoto, Shuji; Fujita, Yoshiaki; Kimura, Itsuro; Miyoshi, Mitsuharu; Yamamoto, Hideki [Kyoto Univ. (Japan); Shinohara, Nobuo

    1997-03-01

    The influence of the impurities on the fission cross section measurements for {sup 241}Am and {sup 243}Am has been investigated with the practical results. Following cases have been considered as the influence of impurities; (a) experiments with the {sup 241}Am sample that contains impurities originally, and (b) experiments with the {sup 243}Am sample that contains impurities produced by {alpha}, {beta} decays after the chemical purification. The present study has demonstrated the usefulness of pure samples by the comparison of the experiments using the sample on the market with those using the pure sample processed by the authors. Particularly on the case (b), the correction of the impurity through the periodical measurements was experimentally performed (about 18% around 0.3 eV in 4 weeks after the chemical purification). (author)

  14. Lightest Isotope of Bh Produced via the 209Bi(52Cr,n)260Bh Reaction

    The lightest isotope of Bh was produced in the new 209Bi(52Cr,n)260Bh reaction at the Lawrence Berkeley National Laboratory's 88-Inch Cyclotron. Positive identification was made by observation of eight correlated alpha particle decay chains in the focal plane detector of the Berkeley Gas-Filled Separator. 260Bh decays with a 35-9+19 ms half-life by alpha particle emission mainly by a group at 10.16 MeV. The measured cross section of 59-20+29 pb is compared to model predictions. The influence of the N=152 and Z=108 shells on alpha decay properties is discussed

  15. Neutron density distributions from antiprotonic 208Pb and 209Bi atoms

    Klos, B.; Trzcinska, A.; Jastrzebski, J.; Czosnyka, T.; Kisielinski, M.; Lubinski, P.; Napiorkowski, P.; Pienkowski, L.; Hartmann, F. J.; Ketzer, B.; Ring, P.; Schmidt, R.; von Egidy, T.; Smolanczuk, R.; S. Wycech

    2007-01-01

    The X-ray cascade from antiprotonic atoms was studied for 208Pb and 209Bi. Widths and shifts of the levels due to the strong interaction were determined. Using modern antiproton-nucleus optical potentials the neutron densities in the nuclear periphery were deduced. Assuming two parameter Fermi distributions (2pF) describing the proton and neutron densities the neutron rms radii were deduced for both nuclei. The difference of neutron and proton rms radii /\\r_np equal to 0.16 +-(0.02)_{stat} +-...

  16. Precision laser spectroscopy of the ground state hyperfine splitting of hydrogenlike ^209 Bi^82+

    Klaft, Ingo; Borneis, Stefan; Engel, Thomas; Fricke, Burkhard; Grieser, Ralf; HUBER, GERHARD; Kühl, Thomas; Marx, Dieter; Neumann, Reinhard; Schröder, Sönke; Seelig, Peter; Völker, Lothar

    1994-01-01

    The first direct observation of a hyperfine splitting in the optical regime is reported. The wavelength of the M1 transition between the F = 4 and F = 5 hyperfine levels of the ground state of hydrogenlike ^209 Bi^82+ was measured to be \\lamda_0 = 243.87(4) nm by detection of laser induced fluorescence at the heavy-ion storage ring ESR at GSI. In addition, the lifetime of the laser excited F = 5 sublevel was determined to be \\tau_0 = 0.351(16) ms. The method can be applied to a number of othe...

  17. Measurements of high-energy neutron-induced fission ofnatPb and 209Bi

    Couture A.

    2010-10-01

    Full Text Available The CERN Neutron Time-Of-Flight (n_TOF facility is well suited to measure low cross sections as those of neutron-induced fission in subactinides. The cross section ratios of natPb and 209Bi relative to 235U and 238U were measured using PPAC detectors and a fragment coincidence method that allows us to identify the fission events. The present experiment provides first results for neutron-induced fission up to 1 GeV. Good agreement is found with previous experimental data below 200 MeV. The comparison with proton-induced fission indicates that the limiting regime where neutron-induced and proton-induced fission reach equal cross sections is close to 1 GeV.

  18. New data from the 243Am + 48Ca reaction give cross-bombardment verification of elements 113, 115 and 117

    The reaction 243Am + 48Ca has been reinvestigated to provide new evidence for the discovery of elements 113, 115. Twenty eight new 288115 decay chains were detected in this reaction to increase from three to 31 the number of 288115 atoms observed. In addition, four new decay chains were observed for the first time and assigned to the decay of 289115. These new 289115 events have the same properties for their decay chains as those observed for 289115 populated in the alpha decay of 293117 produced in the 249Bk + 48Ca reaction to provide cross-bombardment evidence. These new high statistics data sets and the cross-bombardment agreement provide definitive evidence for the discoveries of the new elements with Z = 113, 115, 117.

  19. Analysis of 209 Bi and 238 U photofission cross section in the quasi-deuteron region of photonuclear absorption

    An analysis of the photofission reactions in the quasi-deuteron energy range of photonuclear absorption (∼ 30-140 MeV) has been performed for 209 Bi and 238 U nuclei. Experimental cross section data available in the literature have been compared with calculated values obtained from a model in which the incoming photon is assumed to be absorbed by a neutron-proton pair (Levinger's quasi-deuteron photoabsorption), followed by a mechanism of evaporation-fission competition for the excited residual nuclei. The model has been shown to reproduce the main experimental features of 209 Bi and 238 U photofission cross section, although unexplained differences still remain in the case of 238 U-fission by 30-50 MeV incident photons. (author). 49 refs, 10 figs, 2 tabs

  20. Simultaneous description of CF, ICF and TF data of 6,7Li + 209Bi reaction using new ICF mode

    The systematic behavior of the fusion suppression factors and ICF probability as a function of target mass is not well understood, despite the CF experimental data being available for a number of projectile-target systems. In our recent paper, a new method was proposed to calculate the ICF probability which is based on absorption cross sections obtained from the CDCC calculations. In continuation of this work, we have also carried out similar calculations for 6,7Li + 209Bi where the experimental data of CF and ICF is available. In the recent paper by Marta et al., the semi-classical model calculations were attempted to understand CF and ICF data for 6,7Li + 209Bi, which was not explaining the data quite well. Here, we have demonstrated the use of quantum mechanical treatment for simultaneous explanation of CF, ICF and TF over a large energy range

  1. Fission fragment angular distributions in proton-induced fission of 209 Bi(p,t) and 197 Au(p,f)

    De, S S; N H; M. L.

    2001-01-01

      The fission fragment angular distributions have been measured for proton-induced fission of 209Bi and 197Au nuclei using surface barrier detectors at several energies between 25 MeV and 30 MeV. The experimental anisotropies are found to be in agreement with the predictions of the Standard Saddle-Point Statistical Model (SSPSM). The fission cross sections of 209Bi 197Au nuclei were also measured and compared with the previous works.

  2. Fission fragment angular distributions in proton-induced fission of 209 Bi(p,t and 197 Au(p,f

    S. S.

    2001-12-01

    Full Text Available   The fission fragment angular distributions have been measured for proton-induced fission of 209Bi and 197Au nuclei using surface barrier detectors at several energies between 25 MeV and 30 MeV. The experimental anisotropies are found to be in agreement with the predictions of the Standard Saddle-Point Statistical Model (SSPSM. The fission cross sections of 209Bi 197Au nuclei were also measured and compared with the previous works.

  3. Life time of the HFS transition in Li-like {sup 209}Bi{sup 80+}

    Geppert, C.; Noertershaeuser, W. [Institut fuer Kernchemie, Uni Mainz (Germany); GSI, Darmstadt (Germany); Hannen, V.; Joehren, R.; Ortjohann, H.W.; Vollbrecht, J.; Weinheimer, C. [Institut fuer Kernphysik, Uni Muenster (Germany); Kuehl, T. [Institut fuer Kernchemie, Uni Mainz (Germany); GSI, Darmstadt (Germany); Helmholtz Institut Jena (Germany); S' anchez, R.; Winters, D. [GSI, Darmstadt (Germany); Stoehlker, T. [Institut fuer Kernchemie, Uni Mainz (Germany); GSI, Darmstadt (Germany); Helmholtz Institut Jena (Germany); Uni Jena (Germany)

    2014-07-01

    Measuring the hyperfine splitting of heavy, highly charged ions enables tests of QED in strong fields. HFS calculations have a relative uncertainty of more than 10{sup -3} due to the distribution of the magnetic moment (Bohr-Weisskopf-Effekt). With an appropriate comparison of H- and Li-like ions this nuclear structure contribution can be suppressed. Bismuth is a suitable element for these studies, as the HFS splitting for both configurations are in a wavelength range suitable for laser spectroscopy. For this purpose the two ion species were stored in the Experimental Storage Ring at GSI at a velocity of β = 0.71. To efficiently collect the forward emitted photons a specially developed movable detector system was used. Thereby the HFS of Li-like {sup 209}Bi{sup 80+} was successfully measured for the first time. Besides the determination of the transition energy it was possible to extract the lifetime of the transition out of the collected data. The corresponding analysis and the results are presented on this poster.

  4. Life time of the HFS transition in Li-like 209Bi80+

    Measuring the hyperfine splitting of heavy, highly charged ions enables tests of QED in strong fields. HFS calculations have a relative uncertainty of more than 10-3 due to the distribution of the magnetic moment (Bohr-Weisskopf-Effekt). With an appropriate comparison of H- and Li-like ions this nuclear structure contribution can be suppressed. Bismuth is a suitable element for these studies, as the HFS splitting for both configurations are in a wavelength range suitable for laser spectroscopy. For this purpose the two ion species were stored in the Experimental Storage Ring at GSI at a velocity of β = 0.71. To efficiently collect the forward emitted photons a specially developed movable detector system was used. Thereby the HFS of Li-like 209Bi80+ was successfully measured for the first time. Besides the determination of the transition energy it was possible to extract the lifetime of the transition out of the collected data. The corresponding analysis and the results are presented on this poster.

  5. Neutron capture cross section measurements of $^{238}$U, $^{241}$Am and $^{243}$Am at n_TOF

    Koehler, P E; Plag, R

    The increase of the world energy demand and the need of low carbon energy sources have triggered the renaissance and/or enhancement of nuclear energy in many countries. Fundamental nuclear physics can contribute in a practical way to the sustainability and safety of the nuclear energy production and the management of the nuclear waste. There exists a series of recent studies which address the most relevant isotopes, decay data, nuclear reaction channels and energy ranges which have to be investigated in more detail for improving the design of different advanced nuclear systems [1] and nuclear fuel cycles [2]. In this proposal, we aim at the measurement of the neutron capture cross sections of $^{238}$U, $^{241}$Am and $^{243}$Am. All three isotopes are listed in the NEA High Priority Request List [37], are recommended for measurements [1] and play an important role in the nuclear energy production and fuel cycle scenarios. The measurements will provide as well valuable nuclear structure data necessary for the...

  6. Synthesis of element 113 in the reaction 209Bi(70Zn, n)278113

    The convincing candidate event of the isotope of the 113th element, were observed, for the first time, in the 209Bi+70Zn reaction at a beam energy of 349.0 MeV with a total dose of 1.7 x 1019. Alpha decay energies and decay times of the candidates, 278113, 274111, and 270Mt, were (11.68±0.04 MeV, 0.344 ms), (11.15±0.07 MeV, 9.26 ms), and (10.03±0.07 MeV, 7.16 ms), respectively. The production cross section of the isotope was deduced to be 55-45+150 fb(10-39 cm2). The experiment was performed at RIIKEN (The Institute of Physical and Chemical Research) Linear Accelerator (RILAC) Facility. The evaporation residues produced by the reaction with a 70Zn beam provided by the RILAC and the bismuth targets, were separated by a gas-filled recoil separator (GARIS) from the beam particles and the target recoils, and collected at the focus of GARIS. We observed an event of implantation of an evaporation residue in the position-sensitive semiconductor detector followed by four consecutive alpha decays terminated by a spontaneous fission decay. Assignment of the event was based on genetic correlation of sequential alpha decays to the already known nuclides 266Bh and 262Db. The fourth alpha decay and the following spontaneous fission decay were assigned to be the decays of 266Bh and 262Db, respectively because of agreements of decay energies and decay times with the reported values. As a consequence, the preceding three alpha decays were assigned to be ones of 278113, 274111, and 270Mt.

  7. Experimental Cross Sections for Reactions of Heavy Ions and 208Pb, 209Bi, 238U, and 248Cm Targets

    The study of the reactions between heavy ions and 208Pb, 209Bi, 238U, and 248 Cm targets was performed to look at the differences between the cross sections of hot and cold fusion reactions. Experimental cross sections were compared with predictions from statistical computer codes to evaluate the effectiveness of the computer code in predicting production cross sections. Hot fusion reactions were studied with the MG system, catcher foil techniques and the Berkeley Gas-filled Separator (BGS). 3n- and 4n-exit channel production cross sections were obtained for the 238U(18O,xn)256-xFm, 238U(22Ne,xn)260-xNo, and 248Cm(15N,xn)263-xLr reactions and are similar to previous experimental results. The experimental cross sections were accurately modeled by the predictions of the HIVAP code using the Reisdorf and Schaedel parameters and are consistent with the existing systematics of 4n exit channel reaction products. Cold fusion reactions were examined using the BGS. The 208Pb(48Ca,xn)256-xNo, 208Pb(50Ti,xn)258-xRf, 208Pb(51V,xn)259-xDb, 209Bi(50Ti,xn)259-xDb, and 209Bi(51V,xn)260-xSg reactions were studied. The experimental production cross sections are in agreement with the results observed in previous experiments. It was necessary to slightly alter the Reisdorf and Schaedel parameters for use in the HIVAP code in order to more accurately model the experimental data. The cold fusion experimental results are in agreement with current 1n- and 2n-exit channel systematics

  8. Experimental Cross Sections for Reactions of Heavy Ions and 208Pb, 209Bi, 238U, and 248Cm Targets

    Patin, Joshua B.

    2002-05-24

    The study of the reactions between heavy ions and {sup 208}Pb, {sup 209}Bi, {sup 238}U, and {sup 248} Cm targets was performed to look at the differences between the cross sections of hot and cold fusion reactions. Experimental cross sections were compared with predictions from statistical computer codes to evaluate the effectiveness of the computer code in predicting production cross sections. Hot fusion reactions were studied with the MG system, catcher foil techniques and the Berkeley Gas-filled Separator (BGS). 3n- and 4n-exit channel production cross sections were obtained for the {sup 238}U({sup 18}O,xn){sup 256-x}Fm, {sup 238}U({sup 22}Ne,xn){sup 260-x}No, and {sup 248}Cm({sup 15}N,xn){sup 263-x}Lr reactions and are similar to previous experimental results. The experimental cross sections were accurately modeled by the predictions of the HIVAP code using the Reisdorf and Schaedel parameters and are consistent with the existing systematics of 4n exit channel reaction products. Cold fusion reactions were examined using the BGS. The {sup 208}Pb({sup 48}Ca,xn){sup 256-x}No, {sup 208}Pb({sup 50}Ti,xn){sup 258-x}Rf, {sup 208}Pb({sup 51}V,xn){sup 259-x}Db, {sup 209}Bi({sup 50}Ti,xn){sup 259-x}Db, and {sup 209}Bi({sup 51}V,xn){sup 260-x}Sg reactions were studied. The experimental production cross sections are in agreement with the results observed in previous experiments. It was necessary to slightly alter the Reisdorf and Schaedel parameters for use in the HIVAP code in order to more accurately model the experimental data. The cold fusion experimental results are in agreement with current 1n- and 2n-exit channel systematics.

  9. Determination of the {sup 209}Bi(n,{gamma}){sup 210}Bi and {sup 209}Bi(n,{gamma}){sup 210m,g}Bi reaction cross sections in a cold neutron beam

    Borella, A. [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, B-2440 Geel (Belgium); SCK-CEN, Boeretang 200, B-2400 Mol (Belgium); Belgya, T. [Institute of Isotope, Hungarian Academy of Sciences, POB 77, H-1525 Budapest (Hungary); Kopecky, S. [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, B-2440 Geel (Belgium); Gunsing, F. [CEA/Saclay, DSM/Irfu, F-91191 Gif-sur-Yvette (France); Moxon, M. [Hyde Copse 3, Marcham (United Kingdom); Rejmund, M. [GANIL, F-14076 Caen (France); Schillebeeckx, P., E-mail: peter.schillebeeckx@ec.europa.e [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, B-2440 Geel (Belgium); Szentmiklosi, L. [Institute of Isotope, Hungarian Academy of Sciences, POB 77, H-1525 Budapest (Hungary)

    2011-01-15

    Gamma-ray transitions following neutron capture in {sup 209}Bi have been studied at the cold neutron beam facility of the Budapest Neutron Centre. Measurements have been performed using a coaxial HPGe detector with Compton suppression. Partial capture cross sections at a velocity of 2200 m/s (or a neutron energy of 25.3 meV) have been deduced relatively to the one for the 4055 keV transition after thermal neutron capture in {sup 209}Bi. This partial cross section of (8.07 {+-} 0.14) mb has in turn been obtained from measurements with a bismuth nitrate target relatively to the cross section for the 1884 keV transition after thermal neutron capture in {sup 14}N. Shell model calculations have been performed to deduce the half-life of the 3rd excited state at 320 keV and to assign the M1 multipolarity of the 320 keV transition to the ground state. Lower limits of (21.4 {+-} 0.8) mb and (18.2 {+-} 0.7) mb for the cross sections to the ground state and to the isomeric state, respectively, have been deduced from the data for the gamma rays feeding these states. The results obtained in this work are in good agreement with experimental data reported in the literature. The thermal total capture cross section has been compared with the contribution due to observed s-wave resonances.

  10. Measurement of cross sections of the 210Po production reaction by keV-neutron capture of 209Bi

    The cross sections of the 209Bi(n, γ)210gBi reaction were measured in the keV-neutron region, using an activation method with the detection of α rays from 210Po. Pulsed keV neutrons were generated from the 7Li(p, n)7Be reaction by a 1.5-ns bunched proton beam from the 3-MV Pelletron accelerator of the Research Laboratory for Nuclear Reactors at the Tokyo Institute of Technology. The 209Bi samples were metallic bismuth evaporated on a gold backing. After sample irradiation, the 412-keV γrays from the gold backing were measured with on HPGe detector, and then the α rays from 210Po nuclei in the bismuth sample were measured with a Si surface barrier detector. The derived cross sections were 1.9±0.4 mb and 0.62±0.14 mb at the average neutron energies of 30 keV and 534 keV, respectively. The present value at 30 keV is in agreement with the previous measurement at 24 keV of Booth et al., but about a quarter of the evaluation of JENDL Activation cross section File. The present result at 534 keV is the first experimental one around 500 keV, and is about a half of the evaluation of JENDL Activation cross section File. (author)

  11. Measurement of the neutron-induced fission cross-section of {sup 243}Am relative to {sup 235}U from 0.5 to 20 MeV

    Belloni, F.; Milazzo, P.M.; Abbondanno, U.; Fujii, K.; Moreau, C. [Istituto Nazionale di Fisica Nucleare, Trieste (Italy); Calviani, M. [Laboratori Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare, Legnaro (Italy); CERN, Geneva (Switzerland); Colonna, N.; Barbagallo, M.; Marrone, S.; Meaze, M.H.; Tagliente, G.; Terlizzi, R. [Istituto Nazionale di Fisica Nucleare, Bari (Italy); Mastinu, P.; Gramegna, F. [Lab. Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare, Legnaro (Italy); Aerts, G.; Andriamonje, S.; Berthoumieux, E.; Dridi, W.; Gunsing, F.; Pancin, J.; Perrot, L.; Plukis, A. [Irfu, CEA, Gif-sur-Yvette (France); Alvarez, H.; Cano-Ott, D.; Duran, I.; Embid-Segura, M.; Gonzalez-Romero, E.; Paradela, C.; Tarrio, D. [Univ. de Santiago de Compostela, Galicia (Spain); Alvarez-Velarde, F.; Guerrero, C.; Martinez, T.; Villamarin, D.; Vincente, M.C. [Centro de Investigaciones Energeticas Medioambientales y Technologicas, Madrid (Spain); Andrzejewski, J.; Marganiec, J. [Univ. of Lodz (Poland); Audouin, L.; Dillmann, I.; Heil, M.; Kaeppeler, F.; Mosconi, M.; Plag, R.; Voss, F.; Walter, S.; Wisshak, K. [Karlsruhe Inst. of Technology, Eggenstein-Leopoldshafen (Germany). Inst. fuer Kernphysik; Badurek, G.; Jericha, E.; Leeb, H.; Oberhummer, H. [Technische Univ. Wien, Atominstitut der Oesterreichischen Universitaeten, Wien (Austria); Baumann, P.; David, S.; Kerveno, M.; Lukic, S.; Rudolf, G. [IReS, Centre National de la Recherche Scientifique/IN2P3, Strasbourg (France); Becvar, F.; Krticka, M. [Charles Univ., Faculty of Mathematics and Physics, Prague (Czech Republic); Calvino, F.; Cortes, G.; Poch, A.; Pretel, C. [Univ. Politecnica de Catalunya, Barcelona (Spain); Capote, R. [NAPC/Nuclear Data Section, International Atomic Energy Agency, Vienna (Austria); Univ. de Sevilla (Spain); Carrapico, C.; Goncalves, I.; Salgado, J.; Santos, C.; Tavora, L.; Vaz, P. [Inst. Tecnologico e Nuclear, Lisbon (Portugal)] [and others

    2011-12-15

    The ratio of the neutron-induced fission cross-sections of {sup 243}Am and {sup 235}U was measured in the energy range from 0.5 to 20 MeV with uncertainties of {approx} 4%. The experiment was performed at the CERN n{sub T}OF facility using a fast ionization chamber. With the good counting statistics that could be achieved thanks to the high instantaneous flux and the low backgrounds, the present results are useful for resolving discrepancies in previous data sets and are important for future reactors with improved fuel burn-up. (orig.)

  12. Measurement of the neutron-induced fission cross-section of 243Am relative to 235U from 0.5 to 20 MeV

    The ratio of the neutron-induced fission cross-sections of 243Am and 235U was measured in the energy range from 0.5 to 20 MeV with uncertainties of ∼ 4%. The experiment was performed at the CERN nTOF facility using a fast ionization chamber. With the good counting statistics that could be achieved thanks to the high instantaneous flux and the low backgrounds, the present results are useful for resolving discrepancies in previous data sets and are important for future reactors with improved fuel burn-up. (orig.)

  13. Neutron-induced fission cross sections of 233U and 243Am in the energy range 0.5 Mev En 20 MeV @ n_TOF

    Belloni, F; Milazzo, P M; Calviani, M; Colonna, N; Mastinu, P; Abbondanno, U; Aerts, G; Álvarez, H; Álvarez-Velarde, F; Andriamonje, S; Andrzejewski, J; Assimakopoulos, P; Audouin, L; Badurek, G; Baumann, P; Becvár, F; Berthoumieux, E; Calviño, F; Cano-Ott, D; Capote, R; Carrapiço, C; Cennini, P; Chepel, V; Chiaveri, E; Cortes, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillmann, I; Domingo-Pardo, C; Dridi, W; Duran, I; Eleftheriadis, C; Embid-Segura, M; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Fujii, K; Furman, W; Goncalves, I; González-Romero, E; Gramegna, F; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martinez, A; Igashira, M; Jericha, E; Käppeler, F; Kadi, Y; Karadimos, D; Karamanis, D; Kerveno, M; Koehler, P; Kossionides, E; Krticka, M; Lampoudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marrone, S; Martínez, T; Massimi, C; Mengoni, A; Moreau, C; Mosconi, M; Neves, F; Oberhummer, H; O'Brien, S; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Paradela, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Pigni, M T; Plag, R; Plompen, A; Plukis, A; Poch, A; Praena, J; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rubbia, C; Rudolf, G; Rullhusen, P; Salgado, J; Santos, C; Sarchiapone, L; Savvidis, I; Stephan, C; Tagliente, G; Tain, J L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vazl, P; Ventura, A; Villamarin, D; Vincente, M C; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wiescher, M; Wisshak, K

    2011-01-01

    Neutron-induced fission cross-sections of actinides have been recently measured at the neutron time of flight facility n_TOF at CERN in the frame of a research project involving isotopes relevant for nuclear astrophysics and nuclear technologies. Fission fragments are detected by a gas counter with good discrimination between nuclear fission products and background events. Neutron-induced fission cross-sections of 233U and 243Am were determined relative to 235U. The present paper reports the results obtained at neutron energies between 0.5 and 20 MeV.

  14. Thermal neutron capture cross-section measurements of 243Am and 242Pu using the new mini-INCA α- and γ-spectroscopy station

    In the framework of the Mini-INCA project, dedicated to the study of Minor Actinide transmutation process in high neutron fluxes, an α- and γ-spectroscopy station has been developed and installed at the High Flux Reactor of the Laue-Langevin Institut. This set-up allows short irradiations as well as long irradiations in a high quasi-thermal neutron flux and post-irradiation spectroscopy analysis. It is well suited to measure precisely, in reference to 59Co cross-section, neutron capture cross-sections, for all the actinides, in the thermal energy region. The first measurements using this set-up were done on 243Am and 242Pu isotopes. Cross-section values, at En=0.025eV, were found to be (81.8+/-3.6)b for 243Am and (22.5+/-1.1)b for 242Pu. These values differ from evaluated data libraries by a factor of 9% and 17%, respectively, but are compatible with the most recent measurements, validating by the way the experimental apparatus

  15. The use of isotopic correlation technique for determination of sup(241)Am and sup(243)Am concentration in nuclear irradiated fuels

    In the last years the isotopic correlation technique is emerging as a powerful tool for the determination of concentration and isotopic composition of heavy nuclides in the nuclear fuel cycle. Accordingly, this technique has gained significant importance for the safeguard of the nuclear materials as well as for the accounting and build up of actinides elements in the irradiated nuclear fuels. In this work 42 isotopic correlations between the nuclides sup(241)Am and sup(243)Am and post irradiation isotopic data of 7 samples from fuel element BE-124 and 1 sample from fuel element BE-120 from the Obrigheim pressurized water nuclear power reactor, Federal Republic of Germany, were proposed. These isotopic correlations allowed to estimate the isotopic concentrations of sup(241)Am and sup(243)Am with an average deviation, relative to the experimental data obtained from isotopic dilution mass spectrometry technique, of 10%. These results are more precise than those found using the computer code ORIGEN 2 demonstrating the great potential of this technique for the determination of isotopic concentration and build up of those nuclides in irradiated nuclear fuels. The analytical and other experimental aspects of the post irradiation isotopic analysis of nuclear fuels are also discussed. (author)

  16. Fission Cross Sections of {209}Bi, {232}Th, {235}U, {238}U and {237}Np for Intermediate Energy Protons and Deuterons

    Yurevich, V I; Yakovlev, R M; Sosnin, A N

    2001-01-01

    Fission cross sections of {209}Bi, {232}Th, {235}U, {238}U and {237}Np have been measured with 1.0-3.7 GeV protons and 1.0 GeV deuterons. The results are compared with other experimental data, available evaluations and predictions of the theoretical model.

  17. Comparative study of fusion barrier distribution in 16O and 18O induced reactions on 232Th and 209Bi targets

    In order to investigate the influence of projectile excitations and transfer channels, quasi-elastic excitation function measurements with 16,18O projectile on two targets, one heavy (232Th) and the other a lighter target (209Bi) at energies around their Coulomb barrier are investigated. The results are compared with a new CC code CCFULL

  18. Complete and incomplete fusion cross sections for 6Li+209Bi reaction in multi-body classical molecular dynamical model

    Using the multi-body Classical Molecular Dynamics simulation of 6Li+209Bi reaction it is shown that: (i) the breakup of a projectile fragment near the barrier leads to substantial increase in the ICF probabilities; (ii) the expected increase in σCF on relaxation of the rigid-body (RB) constraint on the projectile is compensated by reduction in the flux leading to CF, due to ICF events; (iii) the breakup probability increases with ECM and, for given ECM it also increases as b increases and peaks around some b>0, while cross sections σCF and σTF were calculated for b=0 only Therefore, we present the results of σCF (Complete Fusion) and σTF (Total Fusion) calculations which are obtained at critical impact parameter, bcr, where many ICF channels open up and compare with the calculations performed at b=0 only, where only few ICF channels open up

  19. Lightest Isotope of Bh Produced Via the 209Bi(52Cr,n)260BhReaction

    Nelson, Sarah L.; Gregorich, Kenneth E.; Dragojevic, Irena; Garcia, Mitch A.; Gates, Jacklyn M.; Sudowe, Ralf; Nitsche, Heino

    2007-05-07

    The lightest isotope of Bh known was produced in the new {sup 209}Bi({sup 52}Cr,n){sup 260}Bh reaction at the Lawrence Berkeley National Laboratory's 88-Inch Cyclotron. Positive identification was made by observation of eight correlated alpha particle decay chains in the focal plane detector of the Berkeley Gas-Filled Separator. {sup 260}Bh decays with a 35{sub -9}{sup +19} ms half-life by alpha particle emission mainly by a group at 10.16 MeV. The measured cross section of 59{sub -20}{sup +29} pb is approximately a factor of four larger than compared to recent model predictions. The influences of the N = 152 and Z = 108 shells on alpha decay properties are discussed.

  20. Extended optical model analyses for the 11B+209Bi system at near-Coulomb-barrier energies

    In the framework of an extended optical model approach in which the polarization potential is decomposed into direct-reaction (DR) and fusion parts, simultaneous χ2 analyses of elastic scattering and fusion cross-section data for the 11B+209Bi system at near-Coulomb-barrier energies are performed. We show that the DR and fusion potentials extracted from χ2 analyses separately satisfy the dispersion relation and that the threshold anomaly exhibits in both DR and fusion parts. We find that the analyses using only elastic scattering and fusion data can produce reliable predictions of cross-sections even though the direct reaction cross-section data are not complete. By using the extracted DR potential, we investigate the effects of the projectile breakup on fusion cross-sections. (orig.)

  1. Study of viscosity on the fission dynamics of the excited nuclei 228U produced in 19F + 209Bi reactions

    A two-dimensional (2D) dynamical model based on Langevin equations was applied to study the fission dynamics of the compound nuclei 228U produced in 19F + 209Bi reactions at intermediate excitation energies. The distance between the centers of masses of the future fission fragments was used as the first dimension and the projection of the total spin of the compound nucleus onto the symmetry axis, K, was considered as the second dimension in Langevin dynamical calculations. The magnitude of post-saddle friction strength was inferred by fitting measured data on the average pre-scission neutron multiplicity for 228U. It was shown that the results of calculations are in good agreement with the experimental data by using values of the post-saddle friction equal to 6–8 × 1021s-1. (author)

  2. Fission Cross-section Measurements of (233)U, (245)Cm and (241,243)Am at CERN n_TOF Facility

    Calviani, M; Andriamonje, S; Chiaveri, E; Vlachoudis, V; Colonna, N; Meaze, M H; Marrone, S; Tagliente, G; Terlizzi, R; Belloni, F; Abbondanno, U; Fujii, K; Milazzo, P M; Moreau, C; Aerts, G; Berthoumieux, E; Dridi, W; Gunsing, F; Pancin, J; Perrot, L; Plukis, A; Alvarez, H; Duran, I; Paradela, C; Alvarez-Velarde, F; Cano-Ott, D; Gonzalez-Romero, E; Guerrero, C; Martinez, T; Villamarin, D; Vicente, M C; Andrzejewski, J; Marganiec, J; Assimakopoulos, P; Karadimos, D; Karamanis, D; Papachristodoulou, C; Patronis, N; Audouin, L; David, S; Ferrant, L; Isaev, S; Stephan, C; Tassan-Got, L; Badurek, G; Jericha, E; Leeb, H; Oberhummer, H; Pigni, M T; Baumann, P; Kerveno, M; Lukic, S; Rudolf, G; Becvar, F; Krticka, M; Calvino, F; Capote, R; Carrillo De Albornoz, A; Marques, L; Salgado, J; Tavora, L; Vaz, P; Cennini, P; Dahlfors, M; Ferrari, A; Gramegna, F; Herrera-Martinez, A; Kadi, Y; Mastinu, P; Praena, J; Sarchiapone, L; Wendler, H; Chepel, V; Ferreira-Marques, R; Goncalves, I; Lindote, A; Lopes, I; Neves, F; Cortes, G; Poch, A; Pretel, C; Couture, A; Cox, J; O'brien, S; Wiescher, M; Dillman, I; Heil, M; Kappeler, F; Mosconi, M; Plag, R; Voss, F; Walter, S; Wisshak, K; Dolfini, R; Rubbia, C; Domingo-Pardo, C; Tain, J L; Eleftheriadis, C; Savvidis, I; Frais-Koelbl, H; Griesmayer, E; Furman, W; Konovalov, V; Goverdovski, A; Ketlerov, V; Haas, B; Haight, R; Reifarth, R; Igashira, M; Koehler, P; Kossionides, E; Lampoudis, C; Lozano, M; Quesada, J; Massimi, C; Vannini, G; Mengoni, A; Oshima, M; Papadopoulos, C; Vlastou, R; Pavlik, A; Pavlopoulos, P; Plompen, A; Rullhusen, P; Rauscher, T; Rosetti, M; Ventura, A

    2011-01-01

    Neutron-induced fission cross-sections of minor actinides have been measured using the n_TOF white neutron source at CERN, Geneva, as part of a large experimental program aiming at collecting new data relevant for nuclear astrophysics and for the design of advanced reactor systems. The measurements at n_TOF take advantage of the innovative features of the n_TOF facility, namely the wide energy range, high instantaneous neutron flux and good energy resolution. Final results on the fission cross-section of 233U, 245Cm and 243Am from thermal to 20 MeV are here reported, together with preliminary results for 241Am. The measurement have been performed with a dedicated Fast Ionization Chamber (FIC), a fission fragment detector with a very high efficiency, relative to the very well known cross-section of 235U, measured simultaneously with the same detector.

  3. Calculations of Branching Ratios for Radiative-Capture, One-Proton, and Two-Neutron Channels in the Fusion Reaction $^{209}$Bi+$^{70}$Zn

    Ichikawa, Takatoshi; 10.1143/JPSJ.79.074201

    2010-01-01

    We discuss the possibility of the non-one-neutron emission channels in the cold fusion reaction $^{70}$Zn + $^{209}$Bi to produce the element Z=113. For this purpose, we calculate the evaporation-residue cross sections of one-proton, radiative-capture, and two-neutron emissions relative to the one-neutron emission in the reaction $^{70}$Zn + $^{209}$Bi. To estimate the upper bounds of those quantities, we vary model parameters in the calculations, such as the level-density parameter and the height of the fission barrier. We conclude that the highest possibility is for the 2n reaction channel, and its upper bounds are 2.4$%$ and at most less than 7.9% with unrealistic parameter values, under the actual experimental conditions of [J. Phys. Soc. Jpn. {\\bf 73} (2004) 2593].

  4. Interaction at the barrier in the systems 9,10,11Be+209Bi: Well-established facts and open questions

    The experimental data relative to the interaction for the systems 9,10,11Be+209Bi at the Coulomb barrier are critically discussed and compared also with present theories. The break-up (BU) of the two loosely bound projectiles, 9,11Be, seems to influence the fusion process by ''hindering'' the fusion cross-sections; but, contrary to expectations, the 11Be halo structure has no influence, since no ''enhancement'' is evident from the existing data. Attempt to describe simultaneously all the 9Be+209Bi system data: fusion, elastic scattering and BU, within a coupled-channel (CC) approach is only partly successful. It is important, from a theoretical viewpoint, to include in the CC formalism as well as possible the BU process both to continuum states as well as to unbound resonances. More accurate and well-focused experiments are also necessary to pin down this problem. (orig.)

  5. Calculations of branching ratios for radiative-capture, one-proton, and two-neutron channels in the fusion reaction 209Bi+70Zn

    We discuss the possibility of the non-one-neutron emission channels in the cold fusion reaction 70Zn+209Bi to produce the element Z=113. For this purpose, we calculate the evaporation-residue cross sections of one-proton, radiative-capture, and two-neutron emissions relative to the one-neutron emission in the reaction 70Zn+209Bi. To estimate the upper bounds of those quantities, we vary model parameters in the calculations, such as the level-density parameter and the height of the fission barrier. We conclude that the highest possibility is for the 2n reaction channel, and its upper bounds are 2.4% and at most less than 7.9% with unrealistic parameter values, under the actual experimental conditions of [J.Phys.Soc.Jpn.73(2004)2593]. (author)

  6. Breakup of 9Be on 209Bi above and near the Coulomb barrier as a molecular single-particle effect: Its influence on complete fusion and scattering

    The breakup of the 9Be projectile on the 209Bi target at bombarding energies above and near the Coulomb barrier is studied in the adiabatic two-center shell model approach. The effect of 9Be→n+2α breakup channel on complete fusion, elastic and inelastic cross sections is investigated. Results show that the breakup of the projectile 9Be could be due to a molecular single-particle effect shortly before the colliding nuclei reach the Coulomb barrier

  7. Cross Sections of the (HI, αn) Channel in the Cold-Fusion-Type Reactions 209 Bi + 40 Ar and 208 Pb + 37 Cl

    By using an off-line radiochemistry technique, production cross sections of 240 Cm(T1/2 = 27 d) in the 209 Bi + 40 Ar and 208 Pb + 37 Cl reactions at the bombarding energy Elab ≤ 230 MeV were determined to be 0,5 ± 0,2 and 0,6 ± 0,3 n b, respectively. The production of 240 Cm was attributed to the 1 n-deexcitation channel of the composite systems 249 Md and 245 Es. The measured 240 Cm production cross sections represent upper cross section limits for the (HI, αn) channel of the reactions under study, which limits are about 100 times lower than the section values reported by Nomura et al. for the (40 Ar, αx n) channels with x = 1,2 of the 209 Bi + 40 Ar reaction at Elab208 MeV. In this connection, presented and discussed is an up-to-date summary of the available data on cross sections of the (HI, αx n) channels in the cold-fusion-type reactions induced by projectiles 37 Cl to 50 Ti on targets of 203,205 Tl, 208 Pb and 209 Bi. Appreciable E C(β+)-delayed fission effects were detected in the 209 Bi + 40 Ar and 206,208 Pb + 37 Cl reactions. In particular, our data reveal the occurrence of E C(β+)-delayed fission in the decay chains 242 Es(E C, ∼7 s) 242 Cf and 238 Bk(E C, ∼2 m) 238 Cm. 28 refs., 4 figs., 4 tabs

  8. Towards measurement of the 209Bi(n,γ)210m,gBi cross sections at SARAF

    The Main Incentives For This Work Is To Exploit The Large Proton Currents And High Neutron Flux Capabilities At The Soreq Applied Research Accelerator Facility (Saraf)Along Witha Liquid Lithium Target To Perform Sensitive Measurements Of Interest In Reactor Design And Safety. The First Measurement To Be Performed Is Neutron Activation Of209bi. This Measurement Is Important For Proposed Pb-Bi Eutectic Coolants For Gen Iv Reactors And For Targets For Accelerator Driven Systems (Ads). The Activity Of One Of The Reaction Products,210mbi, Is Very Difficult To Measure Because Of Long Half-Life (3 Million Years). Successful Measurements And Comparison With The Activation Of 210gbi (The 210bi Ground State) Requires High Neutron Flux And Very Sensitive Measurements. We Plan To Perform The Activation Using The 30 Kevmaxwellianlike Neutron Spectrum Produced By The 7li(P,N)7be Reaction Near Threshold. Subsequent To The Activation, The Plan Is To Measure Directly The γ-Decays From The Decay Products,206tl For The 210mbiand 206pb For The 210gbi Activation, In The Underground Laboratory Hades At Sck-Cen In Mol, Belgium.Level Diagram And Previous Measurements Of This Ratio Are Shown . This Reaction Is Also Of Significance For Nuclear Astrophysics Since It Is The End Of The Chain For S-Process For Nucleo-Synthesis In Heavy Stars, With The Maxwellianneutrons Mimicking Environment In Asymptotic Giant Branch (Agb) Stars

  9. Exploring contributions from incomplete fusion in Li,76+209Bi and Li,76+198Pt reactions

    Parkar, V. V.; Jha, V.; Kailas, S.

    2016-08-01

    We use the breakup absorption model to simultaneously describe the measured cross sections of complete fusion (CF), incomplete fusion (ICF), and total fusion (TF) in nuclear reactions induced by weakly bound nuclei Li,76 on 209Bi and 198Pt targets. The absorption cross sections are calculated using the continuum discretized coupled channels (CDCC) method with different choices of short-range imaginary potentials to get the ICF, CF, and TF cross sections. It is observed that the cross sections for deuteron ICF / deuteron capture and α ICF / α capture are of similar magnitude, in the case of the 6Li projectile, while the cross sections for the triton ICF / triton capture is more dominant than that of α ICF / α capture in the case of the 7Li projectile. Both these observations are also corroborated by the experimental data. The ratio of ICF to TF cross sections, which defines the value of fusion suppression factor, is found to be in agreement with the data available from the literature. The cross-section ratios of CF/TF and ICF/TF show opposite behavior at below-barrier energies the former decreases while the latter increases as the energy is lowered, which shows the dominance of ICF at below-barrier energies. We have also studied the correlation of the ICF cross sections with the noncapture breakup (NCBU) cross sections as a function of energy, which shows that the NCBU is more significant than ICF at below-barrier energies.

  10. Exploring contributions from incomplete fusion in $^{6,7}$Li+$^{209}$Bi and $^{6,7}$Li+$^{198}$Pt reactions

    Parkar, V V; Kailas, S

    2016-01-01

    We use the breakup absorption model to simultaneously describe the measured cross-sections of the Complete fusion (CF), Incomplete fusion (ICF), and Total fusion (TF) in nuclear reactions induced by weakly bound nuclei $^{6,7}$Li on $^{209}$Bi and $^{198}$Pt targets. The absorption cross-sections are calculated using the Continuum Discretized Coupled Channels (CDCC) method with different choices of short range imaginary potentials to get the ICF, CF and TF cross-sections. It is observed that the cross-sections for deuteron-ICF/deuteron-capture are of similar magnitude as the $\\alpha$-ICF/$\\alpha$-capture, in case of $^{6}$Li projectile, while the cross-sections for triton-ICF/triton-capture is more dominant than $\\alpha$-ICF/$\\alpha$-capture in case of $^{7}$Li projectile. Both these observations are also corroborated by the experimental data. The ratio of ICF to TF cross-sections, which defines the value of fusion suppression factor is found to be in agreement with the data available from the literature. The...

  11. Study of the di-nuclear system $^{A}$Rb + $^{209}$Bi (Z$_{1}$ + Z$_{2}$ = 120)

    The exact location of the next spherical shell closures beyond Z = 82, N = 126 is still an open question. According to model predictions shell closures are expected at Z = 114 or 120 or 126 and N = 184. Also experimental data cannot yet give a definite answer. Known nuclei with Z = 114 are too neutron‐deficient with respect to the N = 184 shell and nuclei with Z = 120 and beyond are still unknown. An option for studying reactions of super-heavy systems at Z = 120 and neutron numbers up to 184 becomes possible with the use of $^{209}$Bi targets and neutron‐rich beams. By studying quasi-fission and fusion‐fission reactions, which have significantly larger production cross‐sections than the evaporation residues, a possible influence of shell closures at Z = 120, N = 184 can be explored. Well suitable for such studies will be neutron‐rich rubidium beams at energies of about 5 MeV/u delivered by the HIE‐ISOLDE facility.

  12. Fission cross section calculations for 209Bi target nucleus based on fission reaction models in high energy regions

    Kaplan Abdullah

    2015-01-01

    Full Text Available Implementation of projects of new generation nuclear power plants requires the solving of material science and technological issues in developing of reactor materials. Melts of heavy metals (Pb, Bi and Pb-Bi due to their nuclear and thermophysical properties, are the candidate coolants for fast reactors and accelerator-driven systems (ADS. In this study, α, γ, p, n and 3He induced fission cross section calculations for 209Bi target nucleus at high-energy regions for (α,f, (γ,f, (p,f, (n,f and (3He,f reactions have been investigated using different fission reaction models. Mamdouh Table, Sierk, Rotating Liquid Drop and Fission Path models of theoretical fission barriers of TALYS 1.6 code have been used for the fission cross section calculations. The calculated results have been compared with the experimental data taken from the EXFOR database. TALYS 1.6 Sierk model calculations exhibit generally good agreement with the experimental measurements for all reactions used in this study.

  13. Experimental study of the neutron induced fission cross-section of 234U, 237Np and 243Am with time-of-flight spectrometry technics

    The current work concentrates on the measurements of the nuclear data needed for solving the problem of transmutation of radiotoxic waste. It includes fission cross-section of 234U in the energy range from thermal to 1 MeV, 237Np and 243Am in the resonance region and average group capture cross-section of 234U and 236U. Almost all of these data are recommended by IAEA as a first priority needs for transmutation problem. Another objective is to obtain the high resolution data of the fission cross-section of the 234U on the fission barrier to confirm the existence of the fine structure, attributed to the vibrational resonances in the third well of the fission barrier. The Dissertation summarizes more, than 10 years of the experiments, performed on the pulsed neutron sources IBR-2 and IBR-30 of Frank Laboratory of Neutron Physics of the Joint Institute for Nuclear Research (FLNP JINR) in Dubna, Russia; 'Fakel' of Russian Scientific Center 'Kurchatov's Institute' and n-TOF of CERN. The TOF technique was used for neutron energy spectrometry and various kinds of detectors to mark the fission events. The independent measurements of the same isotopes done on different neutron sources and sometimes with different techniques gives strong, self-consistent set of data. (author)

  14. Measurements of energy dependence of average number of prompt neutrons from neutron-induced fission of 235U, 241Am and 243Am from 0.5 to 12 MeV

    The energy dependence measurements results of average number of prompt neutrons from neutron-induced fission of 235U, 241Am, 243Am and total gamma-rays energy for 235U and 243Am from 0.5 to 12 MeV are presented. The measurements were carried out with neutron beam from uranium target of electron linac of All-Union Scientific Research Institute of Experimental Physics using time-of-flight technique on 28.5 m flight-path. The neutrons and gamma-rays from fission were detected by a big liquid scintillator detector (BLSD) loaded with gadolinium, events of fission - by parallel plate avalanche detector for fission fragments. Measurement of energy dependence of anti νp, Eγtot and determination of BLSD efficiency (relative to anti νp and Eγtot for 252Cf) were carried out simultaneously. Least squares fitting results give anti νp=3.05+0.14degEn for 241Am and anti νp=3.20+.15degEn for 243Am. (orig.)

  15. Developments of 207Pb, 208Pb and 209Bi target wheels in the synthesis of 107Ns, 108Hs and 109Mt

    The developments of 207Pb, 208Pb and 209Bi target wheels and their applications in heavy-ion fusion reactions are reviewed. In both, fabrication and use, the centers of the evaporator or accelerator beams are focussed at wheel radii of 155 mm to specially shaped frames which generate very homogeneous target layers and very constant reaction and counting rates in the experiment. Target areas of up to ∼98% of a wheel's circumference of 974 mm can be provided. The preparation procedures for necessary C backings and protecting layers of C are described, and details are given for the developments of high-vacuum evaporations of 207Pb, 208Pb and 209Bi with deposition yields of 35-55% from tantalum crucibles. The applications of the target wheels in heavy-ion fusion reactions with beams of 54Cr and 58Fe at energies near the Coulomb barrier and intensities of ∼1012 particles/s are mentioned. The target parameters for the production runs of the new chemical elements 107Ns, 108Hs and 109Mt are included. (orig.)

  16. Calculation of neutron cross sections for 90Zr, 208Pb and 209Bi in the energy range of 0.5-25 MeV by using the optical model potentials

    Neutron total cross sections and differential elastic scattering cross sections for the nuclides 90Zr, 208Pb and 209Bi were calculated using different global spherical optical potential (SOP) parameter sets at neutron energies from 0.5-25 MeV. Calculated cross sections for the corresponding nuclides were compared with their experimental data obtained by the EXFOR file to select the best fit parameter sets. It is found that the parameter sets of Ferer Rapaport for 90Zr and Bechetti and Greenless for 208Pb and 209Bi are the best fitted set to obtain the experimental data of total cross sections and angular distributions of these nuclides. (author)

  17. The damping of the single-particle proton strengths in 1isub(11/2) and 1jsub(15/2) states of 209Bi

    15 proton states have been mixed with the low-lying vibrational states as well as the vibrational states arising from the giant resonances in 208Pb to search for the broad fragmentations of the 1 'one' j15/2 and 'one' i11/2 states as observed in the most recent (α,t) reaction on 208Pb. The distribution of the shell-model strengths of these two high-spin states can be explained on the basis of the core polarisation effect on these two proton states of 209Bi. Knowledge of the altered shell-model energies of the proton states of 208Pb is necessary for the search for magicity in the superheavy nuclei. (author)

  18. Comparison of reactions for the production of 258,257Db: 208Pb(51V,xn) and 209Bi(50Ti,xn)

    Gates, Jacklyn M.

    2008-01-01

    Excitation functions for the 1n and 2n exit channels of the 208Pb(51V,xn)259-xDb reaction were measured. A maximum cross section of the 1n exit channel of 2070+1100/-760 pb was measured at an excitation energy of 16.0 +- 1.8 MeV. For the 2n exit channel, a maximum cross section of 1660+450/-370 pb was measured at 22.0 +- 1.8 MeV excitation energy. The 1n excitation function for the 209Bi(50Ti,n)258Db reaction was remeasured, resulting in a cross section of 5480+1750/-1370 pb at an excitati...

  19. Energy dependence of the optical potentials for the 9Be +208Pb and 9Be +209Bi systems at near-Coulomb-barrier energies

    Gómez Camacho, A.; Yu, N.; Zhang, H. Q.; Gomes, P. R. S.; Jia, H. M.; Lubian, J.; Lin, C. J.

    2015-04-01

    We analyze the energy dependence of the interacting optical potential, at near barrier energies, for two systems involving the weakly bound projectile 9Be and the heavy 208Pb and 209Bi targets, by the simultaneous fit of elastic scattering angular distributions and fusion excitation functions. The approach used consists of dividing the optical potential into two parts. A short-range potential VF+i WF that is responsible for fusion, and a superficial potential VDR+i WDR for direct reactions. It is found, for both systems studied, that the fusion imaginary potential WF presents the usual threshold anomaly (TA) observed in tightly bound systems, whereas the direct reaction imaginary potential WDR shows a breakup threshold anomaly (BTA) behavior. Both potentials satisfy the dispersion relation. The direct reaction polarization potential predominates over the fusion potential and so a net overall behavior is found to follow the BTA phenomenon.

  20. Neutron-induced fission cross section of (nat)Pb and (209)Bi from threshold to 1 GeV: An improved parametrization

    Tarrio, D; Audouin, L; Berthier, B; Duran, I; Ferrant, L; Isaev, S; Le Naour, C; Paradela, C; Stephan, C; Trubert, D; Abbondanno, U; Aerts, G; Alvarez-Velarde, F; Andriamonje, S; Andrzejewski, J; Assimakopoulos, P; Badurek, G; Baumann, P; Becvar, F; Belloni, F; Berthoumieux, E; Calvino, F; Calviani, M; Cano-Ott, D; Capote, R; Carrapico, C; Carrillo de Albornoz, A; Cennini, P; Chepel, V; Chiaveri, E; Colonna, N; Cortes, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillmann, I; Dolfini, R; Domingo-Pardo, C; Dridi, W; Eleftheriadis, C; Embid-Segura, M; Ferrari, A; Ferreira-Marques, R; Fitzpatrick, L; Frais-Koelbl, H; Fujii, K; Furman, W; Goncalves, I; Gonzalez-Romero, E; Goverdovski, A; Gramegna, F; Griesmayer, E; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martinez, A; Igashira, M; Jericha, E; Kadi, Y; Kappeler, F; Karadimos, D; Karamanis, D; Kerveno, M; Ketlerov, V; Koehler, P; Konovalov, V; Kossionides, E; Krticka, M; Lampoudis, C; Leeb, H; Lederer, C; Lindote, A; Lopes, I; Losito, R; Lozano, M; Lukic, S; Marganiec, J; Marques, L; Marrone, S; Martinez, T; Massimi, C; Mastinu, P; Mendoza, E; Mengoni, A; Milazzo, P.M; Moreau, C; Mosconi, M; Neves, F; Oberhummer, H; O'Brien, S; Oshima, M; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Pigni, M.T; Plag, R; Plompen, A; Plukis, A; Poch, A; Praena, J; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, C; Rudolf, G; Rullhusen, P; Salgado, J; Santos, C; Sarchiapone, L; Sarmento, R; Savvidis, I; Tagliente, G; Tain, J.L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarin, D; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wendler, H; Wiescher, M; Wisshak, K

    2011-01-01

    Neutron-induced fission cross sections for (nat)Pb and (209)Bi were measured with a white-spectrum neutron source at the CERN Neutron Time-of-Flight (n\\_TOF) facility. The experiment, using neutrons from threshold up to 1 GeV, provides the first results for these nuclei above 200 MeV. The cross sections were measured relative to (235)U and (238)U in a dedicated fission chamber with parallel plate avalanche counter detectors. Results are compared with previous experimental data. Upgraded parametrizations of the cross sections are presented, from threshold energy up to 1 GeV. The proposed new sets of fitting parameters improve former results along the whole energy range.

  1. Measurement of the Neutron Capture Cross Sections of $^{233}$U, $^{237}$Np, $^{240,242}$Pu, $^{241,243}$Am and $^{245}$Cm with a Total Absorption Calorimeter at n_TOF

    Beer, H; Wiescher, M; Cox, J; Rapp, W; Embid, M; Dababneh, S

    2002-01-01

    Accurate and reliable neutron capture cross section data for actinides are necessary for the poper design, safety regulation and precise performance assessment of transmutation devices such as Fast Critical Reactors or Accelerator Driven Systems (ADS). The goal of this proposal is the measurement of the neutron capture cross sections of $^{233}$U, $^{237}$Np, $^{240,242}$Pu, $^{241,243}$Am and $^{245}$Cm at n_TOF with an accuracy of 5~\\%. $^{233}$U plays an essential role in the Th fuel cycle, which has been proposed as a safer and cleaner alternative to the U fuel cycle. The capture cross sections of $^{237}$Np,$^{240,242}$Pu, $^{241,243}$Am and $^{245}$Cm play a key role in the design and optimization of a strategy for the Nuclear Waste Transmutation. A high accuracy can be achieved at n_TOF in such measurements due to a combination of features unique in the world: high instantaneous neutron fluence and excellent energy resolution of the facility, innovative Data Acquisition System based on flash ADCs and t...

  2. Determination of the neutron resonance parameters for 206Pb and of the thermal neutron capture cross section for 206Pb and 209Bi

    Chapter 1 describes the motivation of the measurements (accelerator driven systems, stellar nucleosynthesis, neutron induced reactions on 206Pb), the present status of the neutron capture data for 206Pb and 209Bi and the structure of this work. In Chapter 2 the basic reaction theory underlying this work is described. The neutron induced reaction mechanism and formalism are explained. The parameterisation of the cross section in terms of R-matrix theory is discussed and we put particular emphasis on the statistical behaviour of the resonance parameters and the impact of the angular distribution of gamma rays following neutron capture. The relation between experimental observables and the resonance parameters is discussed together with general comments related to resonance shape analysis. Chapter 3 is focused on the determination of resonance parameters for 206Pb. We performed high-resolution transmission and capture measurements at the Time-Of-Flight (TOF) facility GELINA of the IRMM at Geel (B) and determined the resonance parameters. For nuclei like 206Pb, where the total width is dominated by Γn, the capture area allows to determine G. Transmission measurements were carried out to determine Γn, and the statistical factor g of resonances. Before performing a Resonance Shape Analysis (RSA) on the transmission and capture data, we verified the neutron flux and resolution at GELINA. We also compared the characteristics of GELINA with those of the n-TOF facility at CERN. A special emphasis is placed on the total energy detection technique using C6D6 detectors. This technique was applied for the determination of the capture cross section. To reduce systematic bias effects on the capture cross section, the response of the detectors was determined by Monte Carlo simulations, which has been validated by experiments. Using these response functions the partial capture cross sections for individual resonances of 206Pb have been deduced, by unfolding the response of the C6D

  3. A new evaluation of neutron data for the 209Bi between 10-5 eV and 20 MeV

    A new evaluation of neutron induced cross-sections on 209Bi has been completed within the full energy range 10-5 eV - 20 MeV and put under ENDF format. A careful study of the resonance region led to a consistent set of resonance parameters. On this basis, the tabulated cross-sections (total, elastic, capture) have been calculated using the Reich-Moore formalism. At higher energies a consistent set of optical model parameters has been obtained by fitting mainly the total cross-section between 0.7 and 150 MeV and elastic scattering angular distributions from 4 to 24 MeV. The so obtained neutron penetrabilities have been used for Hauser-Feshbach statistical model calculations which have been completed with pre-equilibrium and direct interaction components to get elastic and inelastic cross sections, angular distributions, secondary neutron spectra and gamma production. All the results are generally in good agreement with the available experimental data

  4. Excitation functions of residual nuclei production from 40–2600 MeV proton-irradiated 206,207,208,natPb and 209Bi

    Yu E Titarenko; V F Batyaev; V M Zhivun; V O Kudryashov; K A Lipatov; A V Ignatyuk; S G Mashnik

    2007-02-01

    The work is aimed at experimental determination of the independent and cumulative yields of radioactive residual nuclei produced in intermediate-energy proton-irradiated thin targets made of highly isotopic enriched and natural lead (206,207,208,natPb) and 209Bi. 5972 radioactive product nuclide yields have been measured in 55 thin targets induced 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 extracted from the ITEP U-10 proton synchrotron. The measured data have been compared with data obtained at other laboratories as well as with theoretical simulations by seven codes. We found that the predictive power of the tested codes is different but is satisfactory for most of the nuclides in the spallation region, though none of the codes agree well with the data in the whole mass region of product nuclides and all should be improved further.

  5. Modes of transference and rupture of the nucleus with neutron halos 6 He on 209 Bi near of the Coulomb barrier

    In recent experiments, the fusion of the exotic radioactive nucleus 6 He with 209 Bi has been studied for the first time at energies above and below the Coulomb barrier. A considerable enhancement in the fusion was observed, which implies a reduction of about 25% in the nominal fusion barrier. Some previous theoretical works suggest that this striking effect may be caused by the coupling to neutron transfer channels with a positive Q-value which would lead to a neutron flow and the consequent formation of a neck between the projectile and the target. Later, in the current work, we ran two new experiments on the same reaction using the FN Tandem Van de Graaff (10 MV) accelerator and the dual superconducting TwinSol system, both of them belonging to the University of Notre Dame, USA. This time, the purpose was to study one- and two-neutron transfer and the 6 He projectile breakup at laboratory energies of 14.7, 16.2, 17.9, 19.0 and 22.5 MeV. A strong group of 4 He was observed (with an effective Q-value about .5 MeV) whose integrated cross section results exceptionally high, exceeding the fusion cross section both above and below the barrier. The simultaneously measured elastic scattering angular distribution required high total cross sections so that this yield is confirmed. Preliminary coupled channels calculations sing the computer program called Fresco developed at the University of Surrey (England) suggested that the reaction mechanisms may be better described as a direct nuclear breakup and two-neutron transfer to unbound states in 211 Bi. These calculations predicted also an enhancement in the fusion cross section below the barrier due to the transfer and breakup channel coupling, which strongly suggests that this channel is the 'doorway state' that explains the fusion barrier reduction observed in previous experiments. It was found that the 4 He group fully dominates the total reaction cross section at the measured energies and we show evidence that a new

  6. Measurements of neutron-induced fission cross-sections of 205Tl, 204,206,207,208Pb and 209Bi with a multi-section Frisch-gridded ionization chamber

    Neutron-induced fission cross-sections of 205Tl, 204,206,207,208Pb and 209Bi have been measured in the energy range from 30 to 180 MeV. The measurements were performed with quasi-monoenergetic neutron beams using a multi-section Frisch-gridded ionization chamber. The neutron-induced fission cross-sections of 238U were used as reference data. The experimental techniques are described in detail as well as the data processing. The results are compared with existing experimental data

  7. Measurements of Neutron-Induced Fission Cross Sections of 205Tl, 204, 206, 207, 208Pb, and 209Bi using Quasi-Monoenergetic Neutrons in the Energy Range 35 - 174 MeV

    Tutin, Gennady A.; Ryzhov, Igor V.; Eismont, Vilen P.; Mitryukhin, Andrey G.; Oplavin, Valery S.; Soloviev, Sergey M.; Blomgren, Jan; Condè, Henri; Olsson, Nils; Renberg, Per-Ulf

    2005-05-01

    Cross sections for neutron-induced fission of 205Tl, 204, 206, 207, 208Pb, and 209Bi were measured in the energy range from 35 MeV to 174 MeV. The experiments were done at the neutron beam facility of The Svedberg Laboratory, using a multi-section Frisch-gridded ionization chamber for detection of the fission fragments. The neutron-induced fission cross section of 238U was employed as a reference. The results of the measurements are compared with existing experimental data.

  8. Measurements of neutron-induced fission cross-sections of 205Tl, 204,206,207,208Pb and 209Bi with a multi-section Frisch-gridded ionization chamber

    Ryzhov, I. V.; Tutin, G. A.; Mitryukhin, A. G.; Oplavin, V. S.; Soloviev, S. M.; Blomgren, J.; Renberg, P.-U.; Meulders, J. P.; El Masri, Y.; Keutgen, Th.; Prieels, R.; Nolte, R.

    2006-06-01

    Neutron-induced fission cross-sections of 205Tl, 204,206,207,208Pb and 209Bi have been measured in the energy range from 30 to 180 MeV. The measurements were performed with quasi-monoenergetic neutron beams using a multi-section Frisch-gridded ionization chamber. The neutron-induced fission cross-sections of 238U were used as reference data. The experimental techniques are described in detail as well as the data processing. The results are compared with existing experimental data.

  9. Modes of transference and rupture of the nucleus with neutron halos {sup 6} He on {sup 209} Bi near of the Coulomb barrier; Modos de transferencia y rompimiento del nucleo con halo neutronico {sup 6} He sobre {sup 209} Bi cerca de la barrera de Coulomb

    Lizcano C, D

    2003-07-01

    In recent experiments, the fusion of the exotic radioactive nucleus {sup 6} He with {sup 209} Bi has been studied for the first time at energies above and below the Coulomb barrier. A considerable enhancement in the fusion was observed, which implies a reduction of about 25% in the nominal fusion barrier. Some previous theoretical works suggest that this striking effect may be caused by the coupling to neutron transfer channels with a positive Q-value which would lead to a neutron flow and the consequent formation of a neck between the projectile and the target. Later, in the current work, we ran two new experiments on the same reaction using the FN Tandem Van de Graaff (10 MV) accelerator and the dual superconducting TwinSol system, both of them belonging to the University of Notre Dame, USA. This time, the purpose was to study one- and two-neutron transfer and the {sup 6} He projectile breakup at laboratory energies of 14.7, 16.2, 17.9, 19.0 and 22.5 MeV. A strong group of {sup 4} He was observed (with an effective Q-value about .5 MeV) whose integrated cross section results exceptionally high, exceeding the fusion cross section both above and below the barrier. The simultaneously measured elastic scattering angular distribution required high total cross sections so that this yield is confirmed. Preliminary coupled channels calculations sing the computer program called Fresco developed at the University of Surrey (England) suggested that the reaction mechanisms may be better described as a direct nuclear breakup and two-neutron transfer to unbound states in {sup 211} Bi. These calculations predicted also an enhancement in the fusion cross section below the barrier due to the transfer and breakup channel coupling, which strongly suggests that this channel is the 'doorway state' that explains the fusion barrier reduction observed in previous experiments. It was found that the {sup 4} He group fully dominates the total reaction cross section at the

  10. Yield of Radionuclides and Isomers Measured in Fragmentation of the ^{nat}W and ^{186}W (97%) Targets with Protons at 630, 420 and 270 MeV

    Karamian, S A; Chaloun, P; Filossofov, D V; Henzl, V; Henzlova, D; Kalinnikov, V G; Korolev, N A; Lebedev, N A; Novgorodov, A F; Collins, C B; Popescu, I I; Ur, C A

    2004-01-01

    Yields and cross sections of the radioactive nuclide formation have been measured via induced activity gamma-spectra after irradiation of the natural composition W and enriched ^{186)W targets at Dubna synchrocyclotron. Spallation and fission products have been represented among the detected nuclides. The high-spin isomers of Hf and Lu were produced and the isomer-to-ground state ratios could be estimated. The nuclide yields have also been calculated using the LAHET code at 6 values of proton energy in the range from 100 to 800 MeV both for ^{nat)W and for enriched ^{186)W targets. Measured isotope yields are generally in agreement with the calculations, however, the code is incapable to predict the isomer-to-ground state ratios. In experiment, it has been shown that the ^{177m}Lu, ^{178m2}Hf and ^{179m2}Hf high-spin isomers are produced with 2.5 times higher yield in the 97% enriched ^{186)W target as compared to the ^{nat)W target at identical irradiations. This makes significance for the creation of high-a...

  11. Wet-chemistry method for the separation of no-carrier-added 211At/211gPo from 209Bi target irradiated by alpha-beam in cyclotron

    We present a fast and effective wet-chemistry method, used to obtain the pure alpha-emitter 211At/211gPo (T1/2 = 7.214 h/516 ms), produced by 209Bi(α,2n) reaction in NCA form. It is a selective radiochemical separation of the At radionuclides from the target and the impurities, characterized by a radionuclidic purity close to 100%, based on the dissolution and the dilution of the irradiated target in acidic medium, on the extraction with DIPE, followed by the back-extraction with NaOH. As a result, we obtain a yield greater than 90-97% in a range from 0.75M to 2.00M. (author)

  12. Motivation for New Measurements on 241, 242, 243Am Isotopes

    The initial objective of this work was an updated review on the Am isotopes data since the next official release (3.1) of the JEFF3 evaluated data file is foreseen around June 2005. Alternatively, this work searches for the possible reasons of the observed discrepancies between differential and integral measurement results. In particular, strong differences are encountered on σγth values and epithermal branching ratio values for the 241Am. Although the JEF2.2 validation is used as guide in parallel with a systematic study of all differential and integral results available, the need for new measurements clearly shows up. This paper finally draws up a list of desired and feasible new differential and integral measurements on the Am isotopes

  13. Optical model analysis over a wide range of nuclei using polarized neutron scattering data

    Polarized neutron scattering data for the nuclei 27Al, natCr, natCu, 89Y, natW, natPb, 209Bi, 232Th and 238U were analyzed in terms of spherical, coupled channels and microscopic optical model potentials. The measurements at typical 7.75 MeV neutron energy were performed at the Stuttgart SCORPION facility. (author)

  14. Residual nuclide formation in 206,207,208,natPb and 209Bi induced by 0.04 - 2.6 GeV protons as well as in 56Fe induced by 0.3 - 2.6 GeV protons

    This work is aimed at experimental determination of independent and cumulative yields of radioactive residual product nuclei in the intermediate energy proton-irradiated thin targets made of highly isotopic enriched and natural lead (206,207,208,natPb), bismuth (209Bi), and highly isotopic enriched iron (56Fe). 5972 independent and cumulative yields of radioactive residuals nuclei have been measured in 55 thin Pb and 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 Fe target. In both cases, 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 seven 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 describe well the product yields throughout the whole product mass range, and all codes must be further improved. (authors)

  15. New measurement of neutron capture resonances of 209Bi

    Domingo-Pardo, C; Abbondanno, U; Aerts, G; Alvarez-Pol, H; Alvarez-Velarde, F; Andriamonje, Samuel A; Andrzejewski, J; Assimakopoulos, Panayiotis; Audouin, L; Badurek, G; Baumann, P; Becvar, F; Berthoumieux, E; Calviño, F; Cano-Ott, D; Capote, R; Carrillode Albornoz, A; Cennini, P; Chepel, V; Chiaveri, Enrico; Colonna, N; Cortés, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillman, I; Dolfini, R; Dridi, W; Durán, I; Eleftheriadis, C; Embid-Segura, M; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Fitzpatrick, L; Frais-Kölbl, H; Fujii, K; Furman, W; Gallino, R; Gonçalves, I; Gonzalez-Romero, E; Goverdovski, A; Gramegna, F; Griesmayer, E; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martínez, A; Igashira, M; Isaev, S; Jericha, E; Kadi, Y; Kappeler, F; Karamanis, D; Karadimos, D; Kerveno, M; Ketlerov, V; Köhler, P; Konovalov, V; Kossionides, E; Krticka, M; Lamboudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marques, L; Marrone, S; Mastinu, P; Mengoni, A; Milazzo, P M; Moreau, C; Mosconi, M; Neves, F; Oberhummer, Heinz; Oshima, M; O'Brien, S; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Paradela, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Plag, R; Plompen, A; Plukis, A; Poch, A; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, Carlo; Rudolf, G; Rullhusen, P; Salgado, J; Sarchiapone, L; Savvidis, I; Stéphan, C; Tagliente, G; Taín, J L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarín, D; Vincente, M C; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wendler, H; Wiescher, M; Wisshak, K

    2006-01-01

    The neutron capture cross section of Bi209 has been measured at the CERN n TOF facility by employing the pulse-height-weighting technique. Improvements over previous measurements are mainly because of an optimized detection system, which led to a practically negligible neutron sensitivity. Additional experimental sources of systematic error, such as the electronic threshold in the detectors, summing of gamma-rays, internal electron conversion, and the isomeric state in bismuth, have been taken into account. Gamma-ray absorption effects inside the sample have been corrected by employing a nonpolynomial weighting function. Because Bi209 is the last stable isotope in the reaction path of the stellar s-process, the Maxwellian averaged capture cross section is important for the recycling of the reaction flow by alpha-decays. In the relevant stellar range of thermal energies between kT=5 and 8 keV our new capture rate is about 16% higher than the presently accepted value used for nucleosynthesis calculations. At th...

  16. Electrochemical oxidation of 243Am(III) in nitric acid by a terpyridyl-derivatized electrode

    Dares, C. J.; Lapides, A. M.; Mincher, B. J.; Meyer, T. J.

    2015-11-05

    A high surface area, tin-doped indium oxide electrode surface-derivatized with a terpyridine ligand has been applied to the oxidation of trivalent americium to Am(V) and Am(VI) in nitric acid. Potentials as low as 1.8 V vs. the saturated calomel electrode are used, 0.7 V lower than the 2.6 V potential for one-electron oxidation of Am(III) to Am(IV) in 1 M acid. This simple electrochemical procedure provides, for the first time, a method for accessing the higher oxidation states of Am in non-complexing media for developing the coordination chemistries of Am(V) and Am(VI) and, more importantly, for separation of americium from nuclear waste streams.

  17. Fission fragment mass distribution studies for 28Si + 197Au, 209Bi, 235U reactions

    In reactions with heavy ions, complete fusion and quasi-fission are the competing processes at energies above the Coulomb barrier. The quasi-fission process, in which the system reseparates before reaching a compact compound nucleus, is a major hurdle in forming heavy and superheavy evaporation residues (ER) in heavy-ion reactions. Fission fragment mass distribution for the fully equilibrated compound nucleus is decided at the scission point due to a long descent from saddle to scission. At higher excitation energies, the shell effects are washed out and the mass distribution is expected to be symmetric. The width of the distribution strongly depends on the entrance channel properties, such as mass asymmetry, deformation of interacting nuclei, collision energy, and the Coulomb factor Z1 Z2. Any sudden change in the width of the mass distribution would indicate departure from full equilibration, while onset of mass asymmetry or a sudden increase in width would be a strong signal of quasi fission

  18. Fission of 209Bi, natPb and 197Au in the particle field of a fast accelerator driven system

    Highlights: ► Fission rates of Bi, Pb and Au were measured in a particle field similar to that of fast ADS. ► The experimental results on fission rates are in agreement with MCNPX calculations. ► The most up to date fission cross-sections and related parameterizations were used. ► New parameterizations were produced from the published cross-section data. - Abstract: Accelerator driven systems (ADS) are expected to have particle spectra of significantly greater energy range than that of current power reactors. The Energy plus Transmutation (EpT) set-up of the Joint Institute for Nuclear Research, Dubna, Russia, is designed to emulate the neutron spectrum in a fast ADS through the use of a spallation target surrounded by a blanket of natural uranium. The spectrum is further modified by a reflective layer of polyethylene and an internal absorbing layer of cadmium. The spallation target of EpT was irradiated with a beam of 4 GeV deuterons, and the fission rates of bismuth, lead and gold samples, placed in the target-blanket region were recorded using a fission track detector technique. The fission rates were also calculated using the MCNPX Monte Carlo code with the INCL4 cascade model and cross sections for nucleon induced fission obtained from literature. Agreement between the measured and calculated results indicates the model’s ability to predict the particle spectra and spatial distribution

  19. Q- and Z-dependence of angular momentum transfer in deeply inelastic collisions of 86Kr with 209Bi

    The dependence of the in-plane and out-of-plane angular correlations of fragments from fissioning heavy products on the kinetic energy and Z of the light reaction partner have been measured. From the dependence of the angular correlations on Q-value and hence energy loss, together with existing data from which the total angular-integrated cross section as a function of energy loss can be extracted, the dependence of the angular momentum transferred to the heavy product on the initial orbital angular momentum or impact parameter has been determined. The resulting dependence is qualitatively consistent with the sticking limit for a reaction intermediate of touching deformed fragments. More specific nuclear models generally underestimate the angular momentum transfer, although the one-body proximity-friction model accounts for the major fraction of the angular momentum transfer. A recent model incorporating both one-body proximity friction and collective excitations accounts quite well for the observed angular momentum transfer. The Z-dependence of the anisotropy shows the importance of angular momentum fractionation for the less probable events, where the Z of the fissioning system is appreciably less than that of the target. The transferred angular momentum is shown to be fairly strongly aligned along the perpendicular to the reaction plane, with alignment values of 0.6 to 0.8. The component of angular momentum not along the perpendicular to the reaction plane is found to be primarily oriented perpendicular rather than parallel to the recoil directions. The absolute fission probabilities are found to be qualitatively consistent with J-dependent calculations using the J-values deduced from the angular correlations. (Auth.)

  20. Study of comparative reliability of computer simulation codes in estimating the cross sections for intermediate-energy proton interactions with nuclei of ADT materials

    The experimental data obtained by the authors on the production cross sections of residual nuclei in the 100-2600 MeV proton interactions with 59Co, 63,65Cu, nat,206,207,208Pb, 209Bi nuclei (thin targets) and with natW nucleus (thick target) are compared with the results of predictive simulation by ten codes. The reliability of the codes is estimated by quantitative ranking separately for a few combinations of proton energies and target materials making allowance for different generation channels of residual product nuclei. Despite quite satisfactory results of comparing between the experimental and simulated data in some cases, none of the simulation codes can be considered to show the required degree of applicability to all of the reactions studied

  1. Measurement of the scattering of polarized neutrons on heavy nuclei and analysis by means of the optical nuclear model

    In the present thesis experiments are described, which were performed with polarized neutrons at the Stuttgart neutron scattering facility SCORPION. The spectrum of the nuclei studied ranges from the spherical nuclei 206Pb, 208Pb, and 209Bi to the strongly deformed nuclei 181Ta, natW, 232Th, and 228U. Measured was the elastic and inelastic scattering of neutrons at energies around 7.75 MeV in an angular range from 21 to 124 degrees. The detected proton-recoil protons were transformed in line spectra by the unfolding procedure FANTI and corrected to finite geometry (program XJANE). The differential cross sections could be absolutely normed by additional polyethylene measurements. In the following data analysis (in the framework of the spherical and deformed optical model) it has been succeeded to fix the model parameters - especially those of the spin-orbit term. Special regard was dedicated to the study of the imaginary spin-orbit contribution. In all nuclei a significant improvement of the fit resulted, when an imaginary spin-orbit potential was introduced. (orig.)

  2. Elastic magnetic scattering of electrons, and radial distribution of valence nucleons. Study of the magnetisation of 49Ti, 51V, 59Co, 87Sr, 93Nb and 209Bi nuclei

    After an introduction on the use of elastic scattering of electrons, of magnetic scattering, and of their combination, this research thesis describes the theoretical framework of electron magnetic scattering, and the properties of the highest multi-poles. The author then presents the experimental installation, describes the experimental procedure from data acquisition to the derivation of final form factors. These form factors are then analysed and interpreted with respect to valence wave forms. Experimental and analysis results are compared with results of three different Hartree-Fock calculations. The limitations of these interpretations and theoretical calculations are discussed, notably by reference to the most recent calculations on core polarisation and on meson exchange currents. Results are also compared with those of other experiments

  3. Sub-coulomb transfer method of a nucleon for measure orbital radii

    The neutron transfer method is revised to measure neutron orbital radii and possible interest systems to apply it are determined. Its were carried out DWBA preliminary calculations for the system 209 Bi(d,t) 208 Bi. (Author)

  4. Role of projectile breakup in {sup 6}He and {sup 6}Li induced fusion reactions around barrier energies

    Kumari, Anju; Kharab, Rajesh, E-mail: kharabrajesh@rediffmail.com

    2015-09-15

    The influence of projectile breakup on fusion cross section for {sup 6}He + {sup 209}Bi, {sup 6}He + {sup 64}Zn, {sup 6}Li + {sup 209}Bi and {sup 6}Li + {sup 64}Zn reactions at near barrier energies is studied within the framework of quantum diffusion approach. The breakup does not affect the fusion induced by {sup 6}He, whereas a significant suppression for {sup 6}Li induced reaction is observed in below barrier energy region.

  5. Experimental test of a new neutron threshold detector and its application

    2002-01-01

    The possibility of using 209Bi as a new threshold detector to measurc high-energy neutrons was investigated for the first time. At the same time the experiment measured successfully the emitted neutron fiuence rate, energy spectrum and dose equivalent rate distributions in the heavy ion target area using a detector complex including 209Bi, 115In, 27A1, 19F and 12C samples.

  6. Method of preparation of tracer radionuclide 239Np using extraction chromatography

    This poster describes the preparation of tracers 239Np from 243Am. Used method involves stabilization of Np(IV) by ascorbic acid and ferric nitrate, separation of 239Np from 243Am using extraction chromatography and determination of activity of the solution obtained with 239Np using HPGe detector. In the experiment we used the commercially available sorbent TEVA Resin from the company Eichrom Technologies.

  7. Measurements of minor actinides cross sections for transmutation

    The existing reactors produce two kinds of nuclear waste: the fission products and heavy nuclei beyond uranium called minor actinides (Americium and Curium isotopes). Two options are considered: storage in deep geological site and/or transmutation by fast neutron induced fission. These studies involve many neutron data. Unfortunately, these data bases have still many shortcomings to achieve reliable results. The aim of these measurements is to update nuclear data and complement them. We have measured the fission cross section of 243Am (7370 y) in reference to the (n,p) elastic scattering to provide new data in a range of fast neutrons (1-8 MeV). A statistical model has been developed to describe the reaction 243Am (n,f). Moreover, the cross sections from the following reactions have been be extracted from these calculations: inelastic scattering 243Am (n,n') and radiative capture 243Am (n,γ) cross sections. The direct measurements of neutron cross sections are often a challenge considering the short half-lives of minor actinides. To overcome this problem, a surrogate method using transfer reactions has been used to study few isotopes of curium. The reactions 243Am (3He, d)244Cm, 243Am (3He, t)243Cm and 243Am (3He, α)242Am allowed to measure the fission probabilities of 243,244Cm and 242Am. The fission cross sections of 242,243Cm (162,9 d, 28,5 y) and 241Am (431 y) have been obtained by multiplying these fission probabilities by the calculated compound nuclear neutron cross section relative to each channel. For each measurement, an accurate assessment of the errors was realized through variance-covariance studies. For measurements of the reaction 243Am(n,f), the analysis of error correlations allowed to interpret the scope of these measures within the existing measurements. (author)

  8. Neutron elastic scattering in the energy region 1.5 to 4.0 MeV for radiogenic lead and bismuth

    Elastic scattering of 1.5 to 4.0 MeV neutrons from radiogenic lead, Pb sub (r), and 209Bi has been measured using a time-of-flight technique. The experimental results show the existence of a b broad maximun in the angle integrated elastic cross section centered at a neutron energy of about 3 MeV for both elements. Further, this cross-section maximum is more pronounced for 209Bi than for Pb sub (r). The data were analysed in terms of an optical model potential with spherical symmetry. The energy dependence of the total shape elastic cross sections calculated for Pb sub (r) and 209Bi from this model shows only minor differences, which are caused by the small mass difference and the fact that nuclear structure effects are not taken into account in the optical model. The observed cross section differences between Pb sub (r) and 209Bi have been explained as a compound nucleus effect caused by the essentially larger ground state spin of 209Bi as compared to Pb sub (r). Different formalisms have been used to correct the calculated compound elastic cross sections for level width fluctuations. (Author)

  9. Laser spectroscopy of the ground-state hyperfine structure in H-like and Li-like bismuth

    The LIBELLE experiment performed at the experimental storage ring (ESR) at the GSI Helmholtz Center in Darmstadt aims for the determination of the ground state hyperfine (HFS) transitions and lifetimes in hydrogen-like (209Bi82+) and lithium-like (209Bi80+) bismuth. The study of HFS transitions in highly charged ions enables precision tests of QED in extreme electric and magnetic fields otherwise not attainable in laboratory experiments. While the HFS transition in H-like bismuth was already observed in earlier experiments at the ESR, the LIBELLE experiment succeeded for the first time to measure the HFS transition in Li-like bismuth in a laser spectroscopy experiment

  10. High-energy neutron-induced fission cross sections of natural lead and bismuth-209

    Calviño Tavares, Francisco; Cortés Rossell, Guillem Pere; Poch Parés, Agustí; Pretel Sánchez, Carme

    2011-01-01

    The CERN Neutron Time-Of-Flight (n TOF) facility is well suited to measure small neutron- induced ssion cross sections, as those of subactinides. The cross section ratios of natPb and 209Bi relative to 235U and 238U were measured using PPAC detectors. The fragment coincidence method allows to unambiguously identify the ssion events. The present experiment provides the rst results for neutron-induced ssion up to 1 GeV for natPb and 209Bi. A good agreement with previous exper...

  11. Self-energy correction to the hyperfine structure splitting of the 1 s and 2 s states in hydrogen ions

    The one-loop self-energy correction to the hyperfine structure splitting of the 1 s- and 2 s-states of hydrogenlike ions is calculated both for the point and finite nucleus. The results of the calculation are combined with other corrections to find the ground state hyperfine splitting in lithiumlike 209 Bi80+ and 165 Ho64+

  12. The vacuum-polarization contribution to the hyperfine structure splitting of hydrogen-like atoms

    A calculation of the vacuum-polarization contribution to the hyperfine splitting for hydrogen-like atoms is presented. The extended nuclear charge distribution is taken into account. For the experimentally interesting case 209Bi82+ we predict a Δλ = -1.6 nm shift for the transition wave length of the ground state hyperfine splitting. (orig.)

  13. Performance and operation of advanced superconducting electron cyclotron resonance ion source SECRAL at 24 GHz.

    Zhao, H W; Lu, W; Zhang, X Z; Feng, Y C; Guo, J W; Cao, Y; Li, J Y; Guo, X H; Sha, S; Sun, L T; Xie, D Z

    2012-02-01

    SECRAL (superconducting ECR ion source with advanced design in Lanzhou) ion source has been in routine operation for Heavy Ion Research Facility in Lanzhou (HIRFL) accelerator complex since May 2007. To further enhance the SECRAL performance in order to satisfy the increasing demand for intensive highly charged ion beams, 3-5 kW high power 24 GHz single frequency and 24 GHz +18 GHz double frequency with an aluminum plasma chamber were tested, and some exciting results were produced with quite a few new record highly charged ion beam intensities, such as (129)Xe(35+) of 64 eμA, (129)Xe(42+) of 3 eμA, (209)Bi(41+) of 50 eμA, (209)Bi(50+) of 4.3 eμA and (209)Bi(54+) of 0.2 eμA. In most cases SECRAL is operated at 18 GHz to deliver highly charged heavy ion beams for the HIRFL accelerator, only for those very high charge states and very heavy ion beams such as (209)Bi(36+) and (209)Bi(41+), SECRAL has been operated at 24 GHz. The total operation beam time provided by SECRAL up to July 2011 has exceeded 7720 hours. In this paper, the latest performance, development, and operation status of SECRAL ion source are presented. The latest results and reliable long-term operation for the HIRFL accelerator have demonstrated that SECRAL performance for production of highly charged heavy ion beams remains improving at higher RF power with optimized tuning. PMID:22380167

  14. Superheavy research at RIKEN

    At RIKEN, Japan, we performed experiments to study the productions and decays of the heaviest elements produced by 208Pb- and 209Bi- based 'cold fusion' reactions. A gas-filled recoil separator GARIS was used for the study. In the study of 209Bi(70Zn, n) reaction, we observed two decay chains originating from an isotope of the 113th element, 178113, which were assigned firstly by generic correlation of the alpha decay chains connected into the previously known decay of 266Bh and 262Db via previously unknown alpha decays of 278113, 274Rg, and 270Mt. In addition, decay properties of an isotope 266Bh and its daughter nucleus 262Db produced by the 248Cm(23Na, 5n) reaction were studied. 266Bh was clearly identified from the correlation of the known nuclide, 262Db, providing further confirmation of the discovery of 278113.

  15. Production and decay properties of 272111 and its daughter nuclei

    The production and decay of 272111 has been investigated using a gas-filled recoil ion separator in irradiations of 209Bi targets with 64Ni beam at 320, 323 and 326 MeV. We have observed 14 α-decay chains in total, that can be assigned, on the basis of their time correlations, to subsequent decays from 272111 produced in the 209Bi(64Ni, 1n) reaction. The present result is the first clear confirmation for the discovery of 272111 and its α-decay products, 264Bh and 268Mt, reported previously by a GSI group. New information on their half-lives and decay energies as well as the excitation function is presented. (author)

  16. Transition energy and lifetime for the ground state hyperfine splitting of high Z lithium-like ions

    Shabaev, V M; Tupitsyn, I; Yerokhin, V A; Artemiev, A N; Kühl, T; Tomaselli, M; Zherebtsov, O M

    1998-01-01

    The ground state hyperfine splitting values and the transition probabilities between the hyperfine structure components of high Z lithiumlike ions are calculated in the range Z=49-83. The relativistic, nuclear, QED and interelectronic interaction corrections are taken into account. It is found that the Bohr-Weisskopf effect can be eliminated in a combination of the hyperfine splitting values of the hydrogenlike and lithiumlike ions of an isotope. This gives a good possibility for testing the QED effects in a combination of the strong electric and magnetic fields of the heavy nucleus. Using the experimental result for the 1s hyperfine splitting in ^{209}Bi^{82+}, the 2s hyperfine splitting in ^{209}Bi^{80+} is calculated to be \\Delta E=0.7981(2) eV while the contribution derived from QED constitutes 0.0007(1) eV.

  17. High-energy Neutron-induced Fission Cross Sections of Natural Lead and Bismuth-209

    Tarrio, D; Carrapico, C; Eleftheriadis, C; Leeb, H; Calvino, F; Herrera-Martinez, A; Savvidis, I; Vlachoudis, V; Haas, B; Koehler, P; Vannini, G; Oshima, M; Le Naour, C; Gramegna, F; Wiescher, M; Pigni, M T; Audouin, L; Mengoni, A; Quesada, J; Becvar, F; Plag, R; Cennini, P; Mosconi, M; Rauscher, T; Couture, A; Capote, R; Sarchiapone, L; Vlastou, R; Domingo-Pardo, C; Dillmann, I; Pavlopoulos, P; Karamanis, D; Krticka, M; Jericha, E; Ferrari, A; Martinez, T; Trubert, D; Oberhummer, H; Karadimos, D; Plompen, A; Isaev, S; Terlizzi, R; Cortes, G; Cox, J; Cano-Ott, D; Pretel, C; Colonna, N; Berthoumieux, E; Vaz, P; Heil, M; Lopes, I; Lampoudis, C; Walter, S; Calviani, M; Gonzalez-Romero, E; Embid-Segura, M; Stephan, C; Igashira, M; Papachristodoulou, C; Aerts, G; Tavora, L; Berthier, B; Rudolf, G; Andrzejewski, J; Villamarin, D; Ferreira-Marques, R; Tain, J L; O'Brien, S; Reifarth, R; Kadi, Y; Neves, F; Poch, A; Kerveno, M; Rubbia, C; Lazano, M; Dahlfors, M; Wisshak, K; Salgado, J; Dridi, W; Ventura, A; Andriamonje, S; Assimakopoulos, P; Santos, C; Voss, F; Ferrant, L; Patronis, N; Chiaveri, E; Guerrero, C; Perrot, L; Vicente, M C; Lindote, A; Praena, J; Baumann, P; Kappeler, F; Rullhusen, P; Furman, W; David, S; Marrone, S; Tassan-Got, L; Gunsig, F; Alvarez-Velarde, F; Massimi, C; Mastinu, P; Pancin, J; Papadopoulos, C; Tagliente, G; Haight, R; Chepel, V; Kossionides, E; Badurek, G; Marganiec, J; Lukic, S; Pavlik, A; Goncalves, I; Duran, I; Alvarez, H; Abbondanno, U; Fujii, K; Milazzo, P M; Moreau, C

    2011-01-01

    The CERN Neutron Time-Of-Flight (n\\_TOF) facility is well suited to measure small neutron-induced fission cross sections, as those of subactinides. The cross section ratios of (nat)Pb and (209)Bi relative to (235)U and (238)U were measured using PPAC detectors. The fragment coincidence method allows to unambiguously identify the fission events. The present experiment provides the first results for neutron-induced fission up to 1 GeV for (nat)Pb and (209)Bi. A good agreement with previous experimental data below 200 MeV is shown. The comparison with proton-induced fission indicates that the limiting regime where neutron-induced and proton-induced fission reach equal cross section is close to 1 GeV.

  18. Method of measurement of cross sections of heavy nuclei fission induced by intermediate energy protons

    The purpose of this work is experimental studies of the energy dependence of the fission cross sections of heavy nuclei, natPb, 209Bi, 232Th, 233U, 235U, 238U, 237Np and 239Pu, by protons at the energies from 200 to 1000 MeV. At present experiment the method based on use of the gas parallel plate avalanche counters (PPACs) for registration of complementary fission fragments in coincidence and the telescope of scintillation counters for direct counting of the incident protons on the target has been used. First preliminary results of the energy dependences of proton induced fission cross sections for natPb, 209Bi, 235U and 238U are reported. (author)

  19. Studies of fragment spin as a function of fragment mass in heavy ion induced fission reactions

    Measurement on fragment spin as a function of its mass has been carried out over a wide range of bombarding energy in 12C, 16O + 209Bi and 12C, 16O + 232Th reactions. The mass dependence of fragment spin for 12C, 16O + 232Th reactions is observed to be in marked contrast to that for the 12C, 16O + 209Bi reactions. The present results have been analysed within the statistical model by taking into account the finite relaxation time for the equilibration of the collective spin modes. It is found that the observed feature in 12C, 16O + 232Th reactions are characteristic of incomplete equilibration of the collective spin modes where the mass relaxation process at extreme mass asymmetry terminates before full statistical equilibration of the collective spin modes are reached

  20. Studies of heavy ion reactions and transuranic nuclei. Progress report, August 1, 1979-July 31, 1980

    The study of heavy-ion reaction mechanisms at the SuperHILAC and LAMPF is reported. Preprints of five articles and manuscripts of four recent conference papers are given, along with complete citations of publications and a list of personnel. Significant work was performed in the following areas: the bombarding energy dependence of the 209Bi + 136Xe reaction; the fragment yields for specific Z and A for projectile-like fragments produced in the reaction of 8.3-MeV/u 56Fe ions with targets of 56Fe, 165Ho, 209Bi, and 238U; and time distributions of fragments from delayed fission after muon capture for muonic 235U, 238U, 237Np, 239Pu, and 242Pu

  1. Nuclear structure of 216Ra at high spin

    S Muralithar; G Rodrigues; R P Singh; R K Bhowmik; P Mukherjee; B Sethi; I Mukherjee

    2012-09-01

    High-spin states of 216Ra ( = 88, = 128) have been investigated through 209Bi(10B, 3n) reaction at an incident beam energy of 55 MeV and 209Bi(11B, 4n) reaction at incident beam energies ranging from 65 to 78 MeV. Based on coincidence data, the level scheme for 216Ra has been considerably extended up to $∼ 33\\hbar$ spin and 7.2 MeV excitation energy in the present experiment with placement of 28 new -transitions over what has been reported earlier. Tentative spin-parity assignments are done for the newly proposed levels on the basis of the DCO ratios corresponding to strong gates. Empirical shell model calculations were carried out to provide an understanding of the underlying nuclear structure.

  2. Thermal flucatuations in a classical theory with shape degrees of freedom for heavy ion collisions

    Samaddar, S. K.; Sperber, D.; Zielińska-Pfabe, M.; Sobel, M. I.; Garpman, S. I.

    1981-02-01

    We use a classical dynamical theory with shape degrees of freedom to describe deep inelastic scattering of heavy ions, and include thermal fluctuations by means of the Fokker-Planck equation. The degrees of freedom allow for neck formation, mass transfer, and stretching of the two-nucleus system. Inertias are calculated for these degrees of freedom, and dissipative and conservative forces are used. Fluctuations are calculated by considering the second moments of the distribution and determining a temperature from the excitation energy at each time. We calculate distributions in final energy, angle, charge, and mass, including some double differential cross sections. Results are in good agreement with data. NUCLEAR REACTIONS Classical dynamical model, shape degrees of freedom, Fokker-Planck equation, thermal fluctuations; angular, energy, mass, and charge distributions are calculated for the reactions 209Bi + 84Kr, 209Bi + 136Xe, and 197Au + 63Cu.

  3. Nuclear structure of 216Ra at high spin

    High-spin states of 216Ra (Z = 88, N = 128) have been investigated through 209Bi(10B, 3n) reaction at an incident beam energy of 55 MeV and 209Bi(11B, 4n) reaction at incident beam energies ranging from 65 to 78 MeV. Based on γγ coincidence data, the level scheme for 216Ra has been considerably extended up to ∼ 33 h spin and 7.2 MeV excitation energy in the present experiment with placement of 28 new γ-transitions over what has been reported earlier. Tentative spin-parity assignments are done for the newly proposed levels on the basis of the DCa ratios corresponding to strong gates. Empirical shell model calculations were carried out to provide an understanding of the underlying nuclear structure. (author)

  4. Measurement of fusion cross section with neutron halo nuclei

    Fusion cross sections of 11Be, 10Be and 9Be have been measured on 209Bi target at 30-70MeV. Due to the neutron halo effect of 11Be, a large enhancement or suppression of the fusion cross section around the Coulomb barrier was theoretically predicted. Comparing the excitation function of 11Be with 10Be at near the Coulomb barrier region, no significant difference has been observed. ((orig.))

  5. Update to nuclear data standards for nuclear measurements. Summary report of a consultants' meeting

    This document is an update of the 1991 NEANDC/INDC Nuclear Standards File (INDC(SEC)-101) to indicate the status and extension of cross section standards for the 10B(n,α) reaction in the energy region below 20 Mev; and the H(n,n), 235U9(n,f), 238U(n,f), and 209Bi(n,f) reactions for selected energy regions above 20 Mev. Refs, figs, tabs

  6. Low-energy fusion dynamics of weakly bound nuclei: A time dependent perspective

    Diaz-Torres A.; Boselli M.

    2016-01-01

    Recent dynamical fusion models for weakly bound nuclei at low incident energies, based on a time-dependent perspective, are briefly presented. The main features of both the PLATYPUS model and a new quantum approach are highlighted. In contrast to existing timedependent quantum models, the present quantum approach separates the complete and incomplete fusion from the total fusion. Calculations performed within a toy model for 6Li + 209Bi at near-barrier energies show that converged excitation ...

  7. Formation of superheavy elements in heavy-ion collisions

    Denisov, Vitali

    2001-01-01

    The cold fusion reactions related to 208Pb and 209Bi targets leading to superheavy elements (SHE) with Z=104-112 have been successfully considered in our model recently. Here we briefly discuss this model and extend our consideration to fusion reactions between similar target and projectile. The reactions between weakly deformed target close to Pb and 76Ge, 82Se projectiles are also studied. The available experimental cross-sections are well described. The nucleus-nucleus interaction potentia...

  8. Asymptotic and near-target direct breakup of 6Li and 7Li

    Kalkal, Sunil; Simpson, E. C.; Luong, D. H.; Cook, K. J.; Dasgupta, M.; Hinde, D. J.; Carter, I. P.; Jeung, D. Y.; Mohanto, G.; Palshetkar, C. S.; Prasad, E.; Rafferty, D. C.; Simenel, C.; Vo-Phuoc, K.; Williams, E.; Gasques, L. R.; Gomes, P. R. S.; Linares, R.

    2016-04-01

    Background: Li,76 and 9Be are weakly bound against breakup into their cluster constituents. Breakup location is important for determining the role of breakup in above-barrier complete fusion suppression. Recent works have pointed out that experimental observables can be used to separate near-target and asymptotic breakup. Purpose: Our purpose is to distinguish near-target and asymptotic direct breakup of Li,76 in reactions with nuclei in different mass regions. Method: Charged particle coincidence measurements are carried out with pulsed Li,76 beams on 58Ni and 64Zn targets at sub-barrier energies and compared with previous measurements using 208Pb and 209Bi targets. A detector array providing a large angular coverage is used, along with time-of-flight information to give definitive particle identification of the direct breakup fragments. Results: In interactions of 6Li with 58Ni and 64Zn, direct breakup occurs only asymptotically far away from the target. However, in interactions with 208Pb and 209Bi, near-target breakup occurs in addition to asymptotic breakup. Direct breakup of 7Li into α -t is not observed in interactions with 58Ni and 64Zn. However, near-target dominated direct breakup was observed in measurements with 208Pb and 209Bi. A modified version of the Monte Carlo classical trajectory model code platypus, which explicitly takes into account lifetimes associated with unbound states, is used to simulate sub-barrier breakup reactions. Conclusions: Near-target breakup in interactions with Li,76 is an important mechanism only for the heavy targets 208Pb and 209Bi. There is insignificant near-target direct breakup of 6Li and no direct breakup of 7Li in reactions with 58Ni and 64Zn. Therefore, direct breakup is unlikely to suppress the above-barrier fusion cross section in reactions of Li,76 with 58Ni and 64Zn nuclei.

  9. Sensitivity of calculated cross sections on the optical model parameters

    After reminding the place of the optical model within the framework of nuclear data evaluation we present the sensitivity-analysis of physical quantities deduced from the optical model on the optical potential parameters in the particular case of the interaction n + 209Bi. This analysis is extended to the statistical model used at low incident energies. The consequences on the parameter fitting procedure are described

  10. Proton-induced nuclide production in heavy target elements at medium energies

    Cross sections for the proton-induced production of residual nuclei in natPb and 209Bi were measured for proton energies between 70 MeV and 1.6 GeV. A comparison with calculated cross sections using an INC/E-model, the hybrid model of preequilibrium reactions and a semiempirical formula has been performed showing that for applications which depend on accurate data it is still necessary to measure cross sections. 21 refs., 5 figs

  11. Complete and incomplete fusion competition in 11B-induced fission reaction on medium mass targets at intermediate energies

    Demekhina, N. A.; Karapetyan, G. S.; Balabekyan, A. R.

    2014-01-01

    The cross sections for the binary fission of 197Au, 181Ta and 209Bi targets induced by 11B ions were measured at intermediate energies. The fission products cross sections were studied by means of activation analysis in off-line regime observed gamma-ray spectra. The fission cross section is reconstructed on the basis of charge and mass distribution of the fission products.

  12. Influence of the angular momentum on nuclear fission

    Tanikawa, Masashi [Tokyo Univ. (Japan). Faculty of Science

    1996-03-01

    The effects of the angular momentum on the mechanism of nuclear fission are studied about the reaction systems of compound nucleus of {sup 210}P and {sup 239}Np by the time-of-flight (TOF) method. The reaction systems in this work are {sup 209}Bi+P, {sup 206}Pb+{alpha}, {sup 206}Po+{alpha}, {sup 198}Pt+{sup 12}C, {sup 238}U+P and {sup 232}Th+{sup 7}Li. Target was prepared by vacuum evaporating of each about 100 {mu}g/cm{sup 2} of {sup 209}Bi, {sup 206}Pb and {sup 198}Pt on 10 {mu}g/cm{sup 2} of carbon film. On compound nucleus {sup 210}Po, {sup 210}Po fissions at Ex=45McV but it fissions after 1 or 2 neutrons emission at higher excited energy (Ex=57 MeV). TKE shows almost the same values except higher value of {sup 209}Bi+P. The decreasing tendency of width of TKE distribution with increasing the angular momentum is found at the first time in this work. The effect of the angular momentum on the fission is small in the case of low angular momentum. On the compound nucleus {sup 239}Np, the effects are shown at the asymmetric fission part of the mass distribution. (S.Y.)

  13. Isospin effect on probing nuclear dissipation with fission cross sections

    Tian, J.; Ye, W.

    2016-08-01

    Nuclear dissipation retards fission. Using the stochastic Langevin model, we calculate the drop of fission cross section caused by friction over its standard statistical-model value, σfdrop, as a function of the presaddle friction strength for fissioning nuclei 195Bi, 202Bi, and 209Bi as well as for different angular momenta. We find that friction effects on σfdrop are substantially enhanced with increasing isospin of the Bi system and become greater with decreasing angular momentum. Our findings suggest that in experiments, to better constrain the strength of presaddle dissipation through the measurement of fission excitation functions, it is optimal to yield those compound systems with a high isospin and a low spin. Furthermore, we analyze the data of fission excitation functions of 210Po and 209Bi systems, which are populated in p +209Bi and p +208Pb reactions and which have a high isospin and a low spin, and find that Langevin calculations with a presaddle friction strength of (3-5) ×10-21 s-1 describe these experimental fission data very well.

  14. Translation of selected papers published in Nuclear Constants, No. 3(57), Moscow 1984

    The document contains the English translation of 6 papers selected for the nuclear data interest, (mainly the determination and the evaluation of the fast fission cross sections of 232Th, 235U, 238U, 237Np, 243Am) which were published in ''Topics in Atomic Science and Technology'', Series Nuclear Constants, No. 3(57), Moscow (1984). The original report was distributed as INDC(CCP)-240/G. Refs, figs and tabs

  15. Discoveries of Elements 113, 115 and 117

    Discovery of two isotopes of the new element 117 in the 249Bk + 48Ca reaction is described. A new 243Am + 48Ca experiment was carried out to firmly establish the discoveries of new elements 115 and 113. A total of thirty one decay chains of 288115 are now observed in the Am reaction. In addition, four new decay chains are assigned to 289115.

  16. Neutron-induced fission cross section measurement of 233U, 241Am and 243Am in the energy range 0.5 MeV En 20 MeV at nTOF at CERN

    Belloni, F. [Instituto Nazionale de Fisica Nucleare-Italy and CEA-France; Milazzo, P. M. [Instituto Nazionale de Fisica Nucleare, Trieste, Italy; Calviani, M. [Laboratori Nazionali di Legnaro, Italy and CERN, Geneva, Switzerland; Colonna, N. [Instituto Nazionale di Fisica Nucleare, Bari, Italy; Mastinu, P. F. [INFN, Laboratori Nazionali di Legnaro, Italy; Abbondanno, U. [Instituto Nazionale de Fisica Nucleare, Trieste, Italy; Aerts, G. [French Atomic Energy Commission (CEA), Centre de Saclay, Gif sur Yvette; Alvarez, H. [University of Santiago de Compostela, Spain; Alvarez-Velarde, F. [Centro de Investigaciones Energeticas Medioambientales y Technol., Madrid, Spain; Andriamonje, S. [French Atomic Energy Commission (CEA), Centre de Saclay, Gif sur Yvette; Andrzejewski, J. [University of Lodz, Lodz, Poland; Assimakopoulos, P. A. [University of Ioannina, Greece; Audouin, L. [Centre National de la Recherche Scidntifique/IN2P3-IPN, Orsay, France; Badurek, G. [Vienna University of Technology, Austria; Barbagallo, M. [Instituto Nazionale di Fisica Nucleare, Bari, Italy; Baumann, P. [CNRS, Strasbourg, France; Becvar, F. [Charles University, Prague, Czech Republic; Berthoumieux, E. [French Atomic Energy Commission (CEA), Centre de Saclay, Gif sur Yvette; Calvino, F. [Universidad Politecnica de Madrid, Spain; Cerutti, F. [CERN, Geneva, Switzerland; Cano-Ott, D. [CIEMAT, Spain; Capote, R. [IAEA-Vienna, Austria and Universidad de Sevilla, Spain; Carrapico, C. [Instituto Tecnológico e Nuclear (ITN), Lisbon, Portugal; Carrillo de Albornoz, A. [Instituto Tecnológico e Nuclear (ITN), Lisbon, Portugal; Cennini, P. [CERN, Geneva, Switzerland; Chepel, V. [University of Ciombra, Portugal; Chiaveri, E. [CERN, Geneva, Switzerland; Cortes, G. [Universitat Politecnica de Catalunya, Barcelona, Spain; Couture, A. [University of Notre Dame, IN; Cox, J. [University of Notre Dame, IN; Dahlfors, M. [CERN, Geneva, Switzerland; David, S. [CNRS, Orsay, France; Dillmann, I. [Institut fur Kernphysik, Karlsruhe, Germany; Dolfini, R. [Universita di Pavia, Italy; Domingo-Pardo, C. [CSIC-Universidad de Valencia; Koehler, Paul [ORNL; The n_TOF Collaboration, [CERN, Geneva, Switzerland

    2012-01-01

    Neutron-induced fission cross section measurements of 233U, 243Am and 241Am relative to 235U have been carried out at the neutron time-of-flight facility n TOF at CERN. A fast ionization chamber has been employed. All samples were located in the same detector; therefore the studied elements and the reference 235U target are subject to the same neutron beam.

  17. Analysis of the evaluated data discrepancies for minor actinides and development of improved evaluation

    Ignatyuk, A. [Institute of Physics and Power Engineering, Obninsk (Russian Federation)

    1997-03-01

    The work is directed on a compilation of experimental and evaluated data available for neutron induced reaction cross sections on {sup 237}Np, {sup 241}Am, {sup 242m}Am and {sup 243}Am isotopes, on the analysis of the old data and renormalizations connected with changes of standards and on the comparison of experimental data with theoretical calculation. Main results of the analysis performed by now are presented in this report. (J.P.N.)

  18. Actinides separation and long-lived fission products from the high activity effluent

    The aim of this document is to study the decontamination of a high activity effluent in minor actinides-α transmitters (241Am, 243Am, 243Cm, 245Cm, 237Np, 238Pu, 242Pu, 235U, 238U) and long-life fissions products (133Cs, 137Cs) and then the separation of Am, Cm, Np, Cs and Pu, U traces. (TEC). 16 figs., 1 tab

  19. Measurements of Fission Cross Sections of Actinides

    Wiescher, M; Cox, J; Dahlfors, M

    2002-01-01

    A measurement of the neutron induced fission cross sections of $^{237}$Np, $^{241},{243}$Am and of $^{245}$Cm is proposed for the n_TOF neutron beam. Two sets of fission detectors will be used: one based on PPAC counters and another based on a fast ionization chamber (FIC). A total of 5x10$^{18}$ protons are requested for the entire fission measurement campaign.

  20. Isoscaling and fission modes in the yields of the Kr and Xe isotopes from photofission of actinides

    Drnoyan, J.; Zhemenik, V. I.; Mishinsky, G. V.

    2016-05-01

    Yields of Kr and Xe isotopes in photofission of 232Th, 238U, 237Np, 244Pu, 243Am, and 248Cm were tested for isoscaling dependence. Isoscaling for Kr is revealed. For Xe, isoscaling is found to be affected by the STI and STII fission modes governed by the N = 82 and N = 88 neutron shells. The work was performed at the Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research (JINR).

  1. Placental transfer of americium and plutonium in mice

    Actinide element release to the environment and subsequent transfer through food chains to pregnant women may present a radiation hazard to fetuses in utero. To measure americium incorporation, four groups of pregnant mice were intravenously dosed with four concentrations of 243Am citrate in late pregnancy. Concentrations of 243Am in fetuses, placentas, and maternal femur, liver, carcass and pelt were determined 48 hr after injection. Doses were chosen so that the number of atoms of 243Am in each injected dose was equal to the number of atoms of 239Pu used in an earlier study of transplacental movement. Results indicate that, atom for atom, americium is incorporated into fetal tissue in lesser amounts (10-25 times) than is plutonium when intravenously administered to pregnant mice in equal atom amounts. Tissue analyses indicated that, at low dose levels, the average fraction of the dose incorporated into the fetuses decreased as the dose to the pregnant mouse was increased. A similar pattern was noted for placentas and maternal femurs. Data indicate that one must make extrapolations from low dose data only to make reasonable and realistic estimates of the transplacental movement and fetal incorporation of environmental levels of actinide elements in man and other species. (author)

  2. The newly observed 113th element

    The convincing candidate event of the isotope of the 113th element, 278113, and its daughter nuclei, 274111 and 271Mt, were observed, for the first time, in the 209Bi + 70Zn reaction. The experiment was performed at RIKEN (The Institute of Physical and Chemical Research) Linear Accelerator Facility using a GAs-filled Recoil Ion Separator GARIS. The experiments to confirm the productions and decays of isotopes 265Hs(Z=108), 271Ds(Z=110), 272Rg(Z=111), and 277112(Z=112) were also done. (author)

  3. Statistical interpretation of the correlation between intermediate mass fragment multiplicity and transverse energy

    Multifragment emission following 129Xe+197Au collisions at 30A, 40A, 50A, and 60A MeV has been studied with multidetector systems covering nearly 4π in solid angle. The correlations of both the intermediate mass fragment and light charged particle multiplicities with the transverse energy are explored. A comparison is made with results from a similar system 136Xe+209Bi at 28A MeV. The experimental trends are compared to statistical model predictions. copyright 1999 The American Physical Society

  4. Measurement of nuclear cross sections using radioactive beams

    One of the main applications of the production and use of nuclear radioactive beams is the measurement of nuclear cross sections. In this work is used a 6 He nuclear radioactive beam (β emitting with half life 806.7 ms) for the study of the reaction 6 + 209 Bi which could have several products. This investigation was realized in collaboration with the personnel of the Nuclear Structure laboratory at the University of Notre Dame (U.S.A.) and the National institute of Nuclear Research and CONACyT by Mexico. (Author)

  5. Self-energy correction to the hyperfine structure splitting of hydrogenlike Atoms

    A first testing ground for QED in the combined presence of a strong Coulomb field and a strong magnetic field is provided by the precise measurement of the hyperfine structure splitting of hydrogenlike 209Bi. We present a complete calculation of the one-loop self-energy correction to the first-order hyperfine interaction for various nuclear charges. In the low-Z regime we almost perfectly agree with the Zα expansion, but for medium and high Z there is a substantial deviation. copyright 1996 The American Physical Society

  6. Program DDCS for nucleon and composite particle DDX of nucleon induced reactions up to tens of MeV

    DDCS is a program for calculating the neutron or proton induced reactions of medium-heavy nuclei in the incident energy range up to 50 MeV including 5 emission processes. This program is written in FORTAN-77 on microscopic computer 486. DDCS is constructed within the framework of optical model, generalized master equation of the exciton model, and the evaporation model. The effect of recoil nucleus is considered in this program. DDCS has been used to calculate reactions of n + 56Fe, n + 93Nb, P + 120Sn, P + 197Au, and P + 209Bi. Pretty good results in agreement with the experimental data were obtained

  7. Low-energy fusion dynamics of weakly bound nuclei: A time dependent perspective

    Diaz-Torres, A.; Boselli, M.

    2016-05-01

    Recent dynamical fusion models for weakly bound nuclei at low incident energies, based on a time-dependent perspective, are briefly presented. The main features of both the PLATYPUS model and a new quantum approach are highlighted. In contrast to existing timedependent quantum models, the present quantum approach separates the complete and incomplete fusion from the total fusion. Calculations performed within a toy model for 6Li + 209Bi at near-barrier energies show that converged excitation functions for total, complete and incomplete fusion can be determined with the time-dependent wavepacket dynamics.

  8. Anti p-nucleus interaction

    Status and future prospects of antiproton-nucleus scattering experiments are presented. These scattering experiments were conducted at antiproton beam momentums of 300 and 600 MeV/c on target nuclei of 6Li, 12C, 16O, 18O, 40Ca, 48Ca, and 208Pb. Antiproton-proton reactions investigated antiproton-nucleus bound or resonant states in antiproton reactions with d, 6Li, 12C, 63Cu, and 209Bi. Inelastic scattering experiments investigated the spin-isospin dependence of the NN interactions. 19 refs., 1 fig., 1 tab

  9. Nuclear Matter Incompressibility Effect on the Cross Section of Fusion Reactions with a weakly bound projectile

    Seyyedi, S A

    2015-01-01

    Fusion reactions with a weakly bound projectile are studied using the double-folding model along with a repulsive interaction modifying term. Using this modified potential, including nuclear matter incompressibility effects, the fusion reaction cross sections and suppression parameters are calculated for 9Be +209Bi,208Pb,29Si and 27Al reactions. The results show that applying these effects at energies near the Coulomb barrier improves the agreement between the calculated and experimental cross sections, and modifies the mean values of the suppression parameter.

  10. Low-energy fusion dynamics of weakly bound nuclei: A time dependent perspective

    Diaz-Torres A.

    2016-01-01

    Full Text Available Recent dynamical fusion models for weakly bound nuclei at low incident energies, based on a time-dependent perspective, are briefly presented. The main features of both the PLATYPUS model and a new quantum approach are highlighted. In contrast to existing timedependent quantum models, the present quantum approach separates the complete and incomplete fusion from the total fusion. Calculations performed within a toy model for 6Li + 209Bi at near-barrier energies show that converged excitation functions for total, complete and incomplete fusion can be determined with the time-dependent wavepacket dynamics.

  11. Comparison of Complementary Reactions in the Production of Mt

    Nelson, Sarah; Gregorich, Kenneth; Dragojevic, Irena; Ellison, Paul; Garcia, Mitch Andre; Gates, Jacklyn; Stavsetra, Liv; Ali, Mazhar; Nitsche, Heino

    2009-01-21

    The new reaction 208Pb(59Co,n)266Mt was studied using the Berkeley Gas-filled Separator at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron. A cross section of 7.7+5.2-3.3 pb was measured at a compound nucleus excitation energy of 14.9 MeV. The measured decay properties of 266Mt and its daughters correspond well with existing data. We compare this experimental result to transactinide compound nucleus formation model predictions, and the previously studied 209Bi(58Fe,n)266Mt reaction.

  12. Measurements of neutron-induced fission cross sections of Pb and Bi at intermediate energies

    Neutron-induced fission cross sections of natPb and 209Bi have been measured relative to the 238U(n.f) cross section at energies 96 MeV for lead and 133 MeV for bismuth. The measurements were performed at the quasi-mono-energetic neutron beam facility of The Svedberg Laboratory in Uppsala using Frisch-gridded ionization chamber. The results obtained are compared with other experimental data. The present state of the Bi standard recommended by IAEA is discussed. (author)

  13. Fusion by diffusion model revisited

    A complete set of 27 excitation functions for synthesis of superheavy nuclei produced in cold fusion reactions was analyzed in terms of the "Fusion by Diffusion Model" of Swiatecki et al., modified to account for the angular momentum dependence of the fusion hindrance factor. The data on cold fusion reactions originate from experiments carried out at GSI Darmstadt, RIKEN Tokyo and LBNL Berkeley in which 208Pb and 209Bi targets were bombarded with the variety of projectiles ranging from 48,50Ti to 70Zn. (author)

  14. Nuclear physics research program at the 30 MeV Karaj cyclotron

    Noshad, H. E-mail: hnoshad@seai.neda.net.ir; Soheyli, S.; Lamehi-Rachti, M.; Talebi-Taher, A.R.; Aslani, Gh.; Maboudi-Moghaddam, S.; Rahighi, J.; Kakuee, O.R.; Heydari, N

    2002-08-01

    A versatile reaction chamber and its accessories as well as a multiparameter data acquisition system were designed, assembled, and installed in the R and D hall at NRCAM to allow nuclear measurements. The {sup 209}Bi(p,f) and {sup 197}Au(p,f) reaction experiments at E{sub p}=30 MeV were performed. The good agreement between our experimental results as compared with previously published data are presented here to show the reliability of our apparatus. In the case of the bismuth reaction, the fission cross section obtained by using pair spectrometry as well as its associated error have been measured for the first time.

  15. Studies of giant multipole resonances with intermediate energy heavy ions

    The role of intermediate energy heavy ions in the study of giant multipole resonances is explored, with emphasis on gamma decay coincidence experiments. Experiments on 208Pb bombarded by 22 MeV/nucleon and 84 MeV/nucleon 17O are discussed and compared. The role of Coulomb excitation in the 84 MeV/nucleon data is emphasized and some consequences for study of isovector resonance strength are explored. A comparison of the excitation and decay of the isovector giant dipole resonance in 208Pb and 209Bi excited with 84 MeV/nucleon 17O scattering is presented. 19 refs., 15 figs., 1 tab

  16. Recent Advances in Nuclear Reaction Theories for Weakly Bound Nuclei: Reexamining the Problem of Inclusive Breakup

    Moro, Antonio M.; Lei, Jin

    2016-05-01

    The problem of the calculation of inclusive breakup cross sections in nuclear reactions is reexamined. For that purpose, the theory proposed by Ichimura et al. (Phys Rev C 32:431, 1985) is revisited, both in its prior and post representations. We briefly outline the connection of this theory with that proposed by Udagawa and Tamura (Phys Rev C 24:1348, 1981) and apply both theories to the inclusive breakup of ^6Li on ^{209}Bi at near-barrier energies, comparing also with available data. The relative importance of elastic versus non-elastic breakup, as a function of the incident energy and of the projectile separation energy, is also investigated.

  17. An empirical fit to estimated neutron emission cross sections from proton induced reactions

    Moumita Maiti; Maitreyee Nandy; S N Roy; P K Sarkar

    2003-01-01

    Neutron emission cross section for various elements from 9Be to 209Bi have been calculated using the hybrid model code ALICE-91 for proton induced reactions in the energy range 25 MeV to 105 MeV. An empirical expression relating neutron emission cross section to target mass number and incident proton energy has been obtained. The simple expression reduces the computation time significantly. The trend in the variation of neutron emission cross sections with respect to the target mass number and incident proton energy has been discussed within the framework of the model used.

  18. Effect of the breakup process on the direct reaction with a 6Li projectile

    We investigate the effect of the breakup process on the direct reaction (DR) for 6Li. In order to study this effect, we introduce the experimental and semiexperimental ratio factors Rexpt and Rth by using the semiexperimental and experimental α-production cross sections and DR cross sections. The average values of the ratio Rexpt (Rth) for the 6Li+208Pb and 6Li+209Bi systems are 0.90 (0.91) and 0.86 (0.85), respectively. From these results, it can be seen that the α-production cross sections are the main contribution to the DR cross sections.

  19. Remark on: the neutron spherical optical-model absorption.

    Smith, A. B.; Nuclear Engineering Division

    2007-06-30

    The energy-dependent behavior of the absorption term of the spherical neutron optical potential for doubly magic {sup 208}Pb and the neighboring {sup 209}Bi is examined. These considerations suggest a phenomenological model that results in an intuitively attractive energy dependence of the imaginary potential that provides a good description of the observed neutron cross sections and that is qualitatively consistent with theoretical concepts. At the same time it provides an alternative to some of the arbitrary assumptions involved in many conventional optical-model interpretations reported in the literature and reduces the number of the parameters of the model.

  20. A quasimolecular treatment of light-particle emission in incomplete-fusion reactions

    The light-particle emission in incomplete-fusion reactions has been analyzed within the framework of a simple model in which the fusion process plays an important role. A quasimolecular interpretation of the fusion has been employed in the model. The numerical results are in good agreement with the experimental data both at forward and backward angles for the reactions 159Tb(14N,α), 209Bi(14N,α) both at the energy 115 MeV and 197Au(22Ne,α) at the energy 178 MeV. (author)

  1. Study of rare alpha decays with scintillating bolometers

    Cardani, L., E-mail: laura.cardani@roma1.infn.it [Dipartimento di Fisica, Sapienza University of Roma, Roma I-00185 (Italy); INFN, Sezione di Roma, Roma I-00185 (Italy)

    2013-08-01

    Rare α decays can be studied with an unprecedented sensitivity by means of scintillating bolometers, as these detectors can provide a large source mass as well as an excellent resolution and can disentangle the nature of the interacting particle thanks to the different light yield. As an example of the results that can be obtained with this technique, I report the conclusive test on the identification of {sup 209}Bi decay and the measurement of the half-life of this isotope. In addition, I present a measurement with a PbWO{sub 4} scintillating bolometer, in which the lead isotopes decays were studied.

  2. Systematics of fission cross sections at the intermediate energy region

    Fukahori, Tokio; Chiba, Satoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-03-01

    The systematics was obtained with fitting experimental data for proton induced fission cross sections of Ag, {sup 181}Ta, {sup 197}Au, {sup 206,207,208}Pb, {sup 209}Bi, {sup 232}Th, {sup 233,235,238}U, {sup 237}Np and {sup 239}Pu above 20 MeV. The low energy cross section of actinoid nuclei is omitted from systematics study, since the cross section has a complicated shape and strongly depends on characteristic of nucleus. The fission cross sections calculated by the systematics are in good agreement with experimental data. (author)

  3. Measurement of nuclear cross sections using radioactive beams; Medicion de secciones eficaces nucleares usando haces radiactivos

    Lizcano, D.; Aguilera, E.F.; Martinez Q, E. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2000-07-01

    One of the main applications of the production and use of nuclear radioactive beams is the measurement of nuclear cross sections. In this work is used a {sup 6} He nuclear radioactive beam ({beta} emitting with half life 806.7 ms) for the study of the reaction {sup 6} + {sup 209} Bi which could have several products. This investigation was realized in collaboration with the personnel of the Nuclear Structure laboratory at the University of Notre Dame (U.S.A.) and the National institute of Nuclear Research and CONACyT by Mexico. (Author)

  4. Observation of 186mTa

    2006-01-01

    Unreported tantalum isomer 18mTa has been produced through the reaction 186W(n,p) by irradiation of natW with 14 MeV neutrons. The activity of 186Ta and 186Ta was measured using HPGe detectors and several X-γ as well as γ-γ coincidence arrangements. The 186mTa has been identified by means of measuring known γ rays from 186Ta p-decay. The half-life of 186mTa has been determined to be (1.5±0.1) min.

  5. Observation of 186mTa

    Unreported tantalum isomer 186mTa has been produced through the reaction 186W(n,p) by irradiation of natW with 14 MeV neutrons. The activity of 186mTa and 186Ta was measured using HPGe detectors and several X-γ as well as γ-γ coincidence arrangements. The 186mTa has been identified by means of measuring known γ rays from 186Ta β-decay. The half-life of 186mTa has been determined to be (1.5±0.1) min. (authors)

  6. Spectroscopic Tools Applied to Element Z = 115 Decay Chains

    Forsberg U.

    2014-03-01

    Full Text Available Nuclides that are considered to be isotopes of element Z = 115 were produced in the reaction 48Ca + 243Am at the GSI Helmholtzzentrum für Schwerionenforschung Darmstadt. The detector setup TASISpec was used. It was mounted behind the gas-filled separator TASCA. Thirty correlated α-decay chains were found, and the energies of the particles were determined with high precision. Two important spectroscopic aspects of the offline data analysis are discussed in detail: the handling of digitized preamplified signals from the silicon strip detectors, and the energy reconstruction of particles escaping to upstream detectors relying on pixel-by-pixel dead-layer thicknesses.

  7. The production of transplutonium elements in France

    The development of the program for the production of transplutonium elements, 241Am, 243Am and 244Cm, in France, required a major effort from the technological and chemical standpoints. Pre-existing hot cells were reconditioned and others specially built for these production operations. From the chemical standpoint, the development of extractive chromatography on the preparative scale has allowed the definition of simple processes. This type of process, initially developed for the treatment of Pu/Al targets, is ideal for the treatment of industrial wastes for their decontamination and for the production of 241Am

  8. Evidence for isotope 265Bh(Z=107)

    New isotope 265Bh (Z=107) was produced in bombardment of a 243Am target with 135 MeV 26Mg ions at HIRFL. Identification was made by observation of correlated α-particle decays between the new isotope 265Bh and its 261Db and 257Lr daughters with four pairs of detectors. The experimental results show that the half-life of 265Bh is 0.94-0.31+0.70 s and its α energy is (9.24 ± 0.05) MeV. (authors)

  9. Preparation of targets for nuclear chemistry experiments at DANCE

    In this paper, we describe the separation chemistry and electrodepositions conducted for the preparation of 241Am, 243Am and 233U targets used for cross-section measurements at DANCE. Thick, adherent deposits were prepared using molecular plating from isopropyl alcohol solutions. Improved yields and thicknesses were observed for 241Am electrodeposition after the material was purified using TRU resin from Eichrom. Similarly, 233U deposits were improved after purification with an anion exchange column in 9 M HBr followed by purification using UTEVA resin from Eichrom. (author)

  10. New Detection System for Heavy Element Research

    Tsyganov, Y S; Voinov, A A; Shumeyko, M V

    2015-01-01

    New detection system design for heavy element research with 48Ca projectile has been reported. This system is based on application of 32 position sensitive strip PIPS detector and low pressure pentane filled TOF detector application in 48Ca induced nuclear reactions. To suppress beam associated background products new version of real time method of active correlations has been applied. Examples of applications in 249Bk+48Ca and 243Am+48Ca reactions are presented. The system development to operate together with the digital ORNL detection system to provide a quick search for recoil to alpha correlation chains has been discussed too.

  11. Sequential determination of Pu and Am radioisotopes in environmental samples; a comparison of two separation procedures

    Two separation methods for the sequential determination of Am and Pu radionuclides are presented and the results obtained are compared. Analysis involves leaching the sample with concentrated nitric acid (HNO3), followed by radiochemical separation using extraction chromatographic resins (UTEVA, TRU) and anion exchange. Sources for alpha spectrometry were prepared by micro-precipitation on neodymium fluoride (NdF3). The chemical recoveries were determined using 242Pu and 243Am tracers. The methods were tested on reference materials and on two sediments. All the results were in good agreement with the reference values. The evaluation of uncertainty is also included

  12. Atlas of giant dipole resonances. Parameters and graphs of photonuclear reaction cross sections

    Parameters of giant dipole resonances (GDR) observed in photonuclear reaction cross sections using various beams of incident photons are presented. Data, given for 200 stable isotopes from 2H to 243Am including their natural compositions, were collected from papers published over the years 1951-1996. GDR parameters, such as energy positions, amplitudes and widths, are included into the table and organized by element, isotope and reaction. Graphs of the majority of the photonuclear reaction cross sections, included in the international nuclear data library EXFOR by the end of 1998, are presented. The graphs are provided for 182 stable isotopes and natural compositions. (author)

  13. Rapid determination of 237Np in soil samples by multi-collector inductively-coupled plasma mass spectrometry and gamma spectrometry

    Yi, Xiaowei; Shi, Yanmei; Xu, Jiang; He, Xiaobing; ZHANG, HAITAO; Lin, Jianfeng

    2013-01-01

    A radiochemical procedure is developed for the determination of 237Np in soil with multi-collector inductively-coupled plasma mass spectrometry (MC-ICP-MS) and gamma-spectrometry. 239Np (milked from 243Am) was used as an isotopic tracer for chemical yield determination. The neptunium in the soil is separated by thenoyl-trifluoracetone extraction from 1 M HNO3 solution after reducing Np to Np(IV) with ferrous sulfamate, and then purified with Dowex 1 × 2 anion exchange resin. 239Np in the resu...

  14. Spectroscopy of element 115 decay chains

    Rudolph, Dirk [Lund University, Sweden; Forsberg, U. [Lund University, Sweden; Golubev, P. [Lund University, Sweden; Sarmiento, L. G. [Lund University, Sweden; Yakushev, A. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Andersson, L.-L. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Di Nitto, A. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Duehllmann, Ch. E. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Gates, J. M. [Lawrence Berkeley National Laboratory (LBNL); Gregorich, K. E. [Lawrence Berkeley National Laboratory (LBNL); Gross, Carl J [ORNL; Hessberger, F. P. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Herzberg, R.-D [University of Liverpool; Khuyagbaatar, J. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Kratz, J. V. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Rykaczewski, Krzysztof Piotr [ORNL; Schaedel, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Aberg, S. [Lund University, Sweden; Ackermann, D. [GSI-Hemholtzzentrum fur Schwerionenforschung, Darmstadt, Germany; Block, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Brand, H. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Carlsson, B. G. [Lund University, Sweden; Cox, D. [University of Liverpool; Derkx, X. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Eberhardt, K. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Even, J. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Fahlander, C. [Lund University, Sweden; Gerl, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Jaeger, E. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kindler, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Krier, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kojouharov, I. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kurz, N. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Lommel, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Mistry, A. [University of Liverpool; Mokry, C. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Nitsche, H. [Lawrence Berkeley National Laboratory (LBNL); Omtvedt, J. P. [Paul Scherrer Institut, Villigen, Switzerland; Papadakis, P. [University of Liverpool; Ragnarsson, I. [Lund University, Sweden; Runke, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Schaffner, H. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Schausten, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Thoerle-Pospiech, P. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Torres, T. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Traut, T. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Trautmann, N. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Tuerler, A. [Paul Scherrer Institut, Villigen, Switzerland; Ward, A. [University of Liverpool; Ward, D. E. [Lund University, Sweden; Wiehl, N. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany

    2013-01-01

    A high-resolution a, X-ray and -ray coincidence spectroscopy experiment was conducted at the GSI Helmholtzzentrum fu r Schwerionenforschung. Thirty correlated a-decay chains were detected following the fusion-evaporation reaction 48Ca + 243Am. The observations are consistent with previous assignments of similar decay chains to originate from element Z = 115. The data includes first candidates of fingerprinting the decay step Mt --> Bh with characteristic X rays. For the first time, precise spectroscopy allows the derivation of excitation schemes of isotopes along the decay chains starting with elements Z > 112. Comprehensive Monte-Carlo simulations accompany the data analysis. Nuclear structure models provide a first level interpretation.

  15. Research of vertical migration of radionuclides in the soil at testing 'Red forest' area

    Researches of vertical migration of Chernobyl origin radionuclides at testing 'Red forest' rea in 5-km ChNPP-zone were carried out. The γ- and β- spectrometer measurements of soil samples were carried out using the anticompton spectrometer and a beta spectrometer. Presence of 60Co, 134, 137Cs, 154,155Eu, 241Am to depth of 30 cm in all soil cuts was fixed. The sites with sod-low-podzol sandy soils on alluvial sands contain 137Cs, 90Sr and 241Am to depth of 60 cm. The presence 243Am and 243Cm was found in the top layers of soils at territory of testing area.

  16. Migration studies of radionuclides at the WIPP site

    A study was made of the effects on radionuclide migration from the solid TRU waste of inorganic and organic ligands in brine media. Typical organic waste meterials were exposed to synthetic brine at 700 for up to 1 year. Pure brine and brine/organic waste extracts were used to determine actinide and lathanide (153Gd, 144Ce, 152Eu, 243Am) distribution coefficients K/sub d/ between geological media and the brine. Results show that brine containing extract from plywood, etc. reduces considerably the K/sub d/

  17. Superheavy research at RIKEN

    Morita, Kosuke [Superheavy Element Laboratory, RIKEN Nishina Center for Accelerator Based Science, RIKEN Hirosawa 2-1, Wako-shi, Saitama 351-0198 (Japan)

    2010-03-01

    At RIKEN, Japan, we performed experiments to study the productions and decays of the heaviest elements produced by {sup 208}Pb- and {sup 209}Bi- based 'cold fusion' reactions. A gas-filled recoil separator GARIS was used for the study. In the study of {sup 209}Bi({sup 70}Zn, n) reaction, we observed two decay chains originating from an isotope of the 113th element, {sup 178}113, which were assigned firstly by generic correlation of the alpha decay chains connected into the previously known decay of {sup 266}Bh and {sup 262}Db via previously unknown alpha decays of {sup 278}113, {sup 274}Rg, and {sup 270}Mt. In addition, decay properties of an isotope {sup 266}Bh and its daughter nucleus {sup 262}Db produced by the {sup 248}Cm({sup 23}Na, 5n) reaction were studied. {sup 266}Bh was clearly identified from the correlation of the known nuclide, {sup 262}Db, providing further confirmation of the discovery of {sup 278}113.

  18. Correlation between strain and defects in Bi implanted Si

    Palade, C.; Lepadatu, A.-M.; Slav, A.; Ciurea, M. L.; Lazanu, S.

    2016-06-01

    The strain in Si containing group-V impurities is a topical subject of study due to its potential applications in quantum computing. In this paper we study 209Bi implanted Si concerning the correlation between the strain produced by stopped Bi ions and trapping characteristics of the defects resulted from implantation. The depths distributions of stopped ions and primary defects are simulated and the distributions of permanent defects are modelled for Si implanted with low fluence 209Bi ions of 28 MeV kinetic energy. For comparison, these depths distributions were similarly calculated for 127I ions with the same fluence and energy, implanted in Si. The results are compared with each other and correlated with the characteristics of traps in these systems, previously obtained. We demonstrate that the intensity of the strain field is the most important factor in changing of trap parameters, while the superposition between the region with strain and the region where defects are located is a second order effect.

  19. Comparison of complementary reactions for the production of 261,262Bh

    Two heavy-ion induced fusion reactions producing 261,262Bh were studied using the Berkeley Gas-filled Separator at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron. An excitation function for the production of 262Bh via the reaction 209Bi(54Cr,n)262Bh was measured with a maximum cross section from a fit to the data of 430 ± 110 pb observed at a compound nucleus excitation energy of 15.7 MeV. New data have been measured for the 1n exit channel of the 208Pb(55Mn, n)262Bh reaction. We present an updated excitation function with an observed maximum cross section of 530±100 pb at a compound nucleus excitation energy of 14.1 MeV. Events corresponding to the 2n exit channel for the 209Bi(54Cr,2n)261Bh and 208Pb(55Mn,2n)261Bh reactions were also observed and are presented as partial excitation functions. The measured decay properties correspond well with existing experimental data. We compare these experimental results to cross section predictions from a model by Swiatecki et al. and discuss entrance channel effects on the magnitude of 1n cross sections

  20. Measurement of activation cross-sections for high-energy neutron-induced reactions of Bi and Pb

    Zaman, Muhammad; Kim, Guinyun; Kim, Kwangsoo; Naik, Haladhara; Shahid, Muhammad; Lee, Manwoo

    2015-08-01

    The cross-sections for 209Bi(n, 4n)206Bi, 209Bi(n, 5n)205Bi, natPb(n, xn)204mPb, natPb(n, xn)203Pb, natPb(n, xn)202mPb,natPb(n, xn)201Pb, natPb(n, xn)200Pb, natPb(n, αxn)203Hg and natPb(n, p xn)202Tl reactions were determined at the Korean Institute of Radiological and Medical Sciences (KIRAMS), Korea in the neutron energy range of 15.2 to 37.2 MeV. The above cross-sections were obtained by using the activation and off-line γ-ray spectrometric technique. The quasi-monoenergetic neutron used for the above reactions are based on the 9Be(p, n) reaction. Simulations of the spectral flux from the Be target were done using the MCNPX program. The cross-sections were estimated with the TALYS 1.6 code using the default parameter. The data from the present work and literature were compared with the data from the EAF-2010 and the TENDL-2013 libraries, and calculated values of TALYS 1.6 code. It shows that appropriate level density model, the γ-ray strength function, and the spin cut-off parameter are needed to obtain a good agreement between experimental data and theoretical values from TALYS 1.6 code.

  1. Studies of heavy-ion reactions and transuranic nuclei

    This report contain papers on the following topics: The Cold-Fusion Saga; Decay Patterns of Dysprosium Nuclei Produced in 32S + 118,124Sn Fusion Reactions; Unexpected Features of Reactions Between Very Heavy Ions at Intermediate Bombarding Energies; Correlations Between Neutrons and Charged Products from the Dissipative Reaction 197Au+208Pb at E/A = 29 MeV; Dissipative Dynamics of Projectile-Like Fragment Production in the Reaction 209Bi+136Xe at E/A = 28.2 MeV; Dynamical Production of Intermediate-Mass Fragments in Peripheral 209Bi+136Xe Collisions at Elab/A = 28.2 MeV; The Rochester 960-Liter Neutron Multiplicity Meter; A Simple Pulse Processing Concept for a Low-Cost Pulse-Shape-Based Particle Identification; A One-Transistor Preamplifier for PMT Anode Signals; A Five-Channel Multistop TDC/Event Handler for the SuperBall Neutron Multiplicity Meter; Construction of the SuperBall -- a 16,000-Liter Neutron Detector for Calorimetric Studies of Intermediate-Energy Heavy-Ion Reactions; A Computer Code for Light Detection Efficiency Calculations for Photo-multipliers of a Neutron Detector; Evaluation of Gd-Loaded Liquid Scintillators for the SuperBall Neutron Calorimeter; and Measurement of the Interaction of Cosmic-Ray μ- with a Muon Telescope

  2. NMR Evidence for the Topologically Nontrivial Nature in a Family of Half-Heusler Compounds

    Zhang, Xiaoming; Hou, Zhipeng; Wang, Yue; Xu, Guizhou; Shi, Chenglong; Liu, Enke; Xi, Xuekui; Wang, Wenhong; Wu, Guangheng; Zhang, Xi-Xiang

    2016-03-01

    Spin-orbit coupling (SOC) is expected to partly determine the topologically nontrivial electronic structure of heavy half-Heusler ternary compounds. However, to date, attempts to experimentally observe either the strength of SOC or how it modifies the bulk band structure have been unsuccessful. By using bulk-sensitive nuclear magnetic resonance (NMR) spectroscopy combined with first-principles calculations, we reveal that 209Bi NMR isotropic shifts scale with relativity in terms of the strength of SOC and average atomic numbers, indicating strong relativistic effects on NMR parameters. According to first-principles calculations, we further claim that nuclear magnetic shieldings from relativistic p1/2 states and paramagnetic contributions from low-lying unoccupied p3/2 states are both sensitive to the details of band structures tuned by relativity, which explains why the hidden relativistic effects on band structure can be revealed by 209Bi NMR isotropic shifts in topologically nontrivial half-Heusler compounds. Used in complement to surface-sensitive methods, such as angle resolved photon electron spectroscopy and scanning tunneling spectroscopy, NMR can provide valuable information on bulk electronic states.

  3. Simulated nucleon–nucleon and nucleon–nucleus reactions in the frame of the cascade exciton model at high and intermediate energies

    A Abdel-Hafiez; Shaker El-Shater; M F Zaki

    2015-04-01

    In this study, we have used the cascade exciton model (CEM) to investigate different characteristics of nuclear reactions. Number of nucleon–nucleon collisions in Pb+Pb collisions as a function of impact parameter and rapidity distributions of negative particles from p+Ar and p+Xe interactions at lab = 200 GeV/c have been studied. We could create inclusive spectra of pions for separate charged states from reactions and total neutron multiplicities per primary reaction at 1000 MeV for different thin targets. Also, cross-sections for the reactions 209Bi(p, f) and 209Bi(n, f) were studied. Interactions of 1.0 GeV protons with C, Al, Cu, Sn, and Pb are presented in this study. All the calculated characteristics are compared with other theoretical calculations and compared with the experimental data. CEM shows good agreement with both theoretical and experimental results. In this study, we have used quantum molecular dynamic (QMD) as a theoretical model to compare our results.

  4. Communication of nuclear data progress No. 23 (2000)

    The 23th issue of Communication of Nuclear Data Progress (CNDP) presents the achievements obtained last year in nuclear data field in China. It includes the measurements of double differential cross section of 9Be at 5.9 and 6.4 MeV and 186W(n,γ)187W reaction cross section from 0.50 to 1.5 MeV; researches on three body breakup process and energy balance in UNF code, theoretical calculations of n + 141Pr, 239,240Pu, P + 209Bi reactions; evaluations of n + 90,91,92,94,96,0Zr, NatCu, 135,136,137,138Ba neutron data, γ + 209Bi photo nuclear reaction data and fission yield from 235U fission; investigation on the systematics of isomeric cross section ratios for neutron-induced reactions around 14 MeV; progress report on prompt γ-ray data evaluation, and a brief report on the test of the fission rate for 238U. Also the activities and cooperation on nuclear data in China are summarized

  5. Impact of temperature on single event upset measurement by heavy ions in SRAM devices

    The temperature dependence of single event upset (SEU) measurement both in commercial bulk and silicon on insulator (SOI) static random access memories (SRAMs) has been investigated by experiment in the Heavy Ion Research Facility in Lanzhou (HIRFL). For commercial bulk SRAM, the SEU cross section measured by 12C ions is very sensitive to the temperature. The temperature test of SEU in SOI SRAM was conducted by 209Bi and 12C ions, respectively, and the SEU cross sections display a remarkable growth with the elevated temperature for 12C ions but keep constant for 209Bi ions. The impact of temperature on SEU measurement was analyzed by Monte Carlo simulation. It is revealed that the SEU cross section is significantly affected by the temperature around the threshold linear energy transfer of SEU occurrence. As the SEU occurrence approaches saturation, the SEU cross section gradually exhibits less temperature dependency. Based on this result, the experimental data measured in HIRFL was analyzed, and then a reasonable method of predicting the on-orbit SEU rate was proposed. (semiconductor devices)

  6. Multiparticle emission in the pre-equilibrium decay of light and heavy nuclei in α-induced reaction up to 60 MeV

    α-particle induced excitation functions for the reactions 55Mn(α,n)58Co, 55Mn(α,2n)57Co, 55Mn(α,3n)56Co, 55Mn(α,4n)55Co, 55Mn(α,αn)54Mn, 55Mn(α,2p3n)54Mn, 55Mn(α,α3n)52Mn, 209Bi(α,3n)210At and 209Bi(α,4n)209At have been measured up to 60 MeV α-particle using the stack foil activation technique. The reactions 55Mn(α,4n)55Co and 55Mn(α,α3n)52Mn have been studied for the first time. The theoretical comparison with a pre-equilibrium (PE) geometry dependent hybrid (GHD) model has been made. The initial exciton number n0=4 with different configurations (1n+2p+1h), (2n+2p+0h) and (2n+1p+1h) has been tested. It is found that configuration (2n+2p+0h) is the best set of choice. The pre-equilibrium fraction fPE of the total excitation function has also been calculated at different excitation energy. (author). 23 refs, 10 figs, 2 tabs

  7. NMR Evidence for the Topologically Nontrivial Nature in a Family of Half-Heusler Compounds

    Zhang, Xiaoming

    2016-03-16

    Spin-orbit coupling (SOC) is expected to partly determine the topologically nontrivial electronic structure of heavy half-Heusler ternary compounds. However, to date, attempts to experimentally observe either the strength of SOC or how it modifies the bulk band structure have been unsuccessful. By using bulk-sensitive nuclear magnetic resonance (NMR) spectroscopy combined with first-principles calculations, we reveal that 209Bi NMR isotropic shifts scale with relativity in terms of the strength of SOC and average atomic numbers, indicating strong relativistic effects on NMR parameters. According to first-principles calculations, we further claim that nuclear magnetic shieldings from relativistic p1/2 states and paramagnetic contributions from low-lying unoccupied p3/2 states are both sensitive to the details of band structures tuned by relativity, which explains why the hidden relativistic effects on band structure can be revealed by 209Bi NMR isotropic shifts in topologically nontrivial half-Heusler compounds. Used in complement to surface-sensitive methods, such as angle resolved photon electron spectroscopy and scanning tunneling spectroscopy, NMR can provide valuable information on bulk electronic states.

  8. Collective dyanamics of intermediate-energy heavy-ion collisions

    Exclusive measurements of massive projectile-like fragments (PLF), intermediate-mass fragments (IMF), light charged particles (lcp), and neutrons have been performed for the reactions 209Bi + 136Xe and 197Au+208Pb at the lower boundary (∼29MeV/u) of the Fermi energy regime. Unexpectedly, the measurements provide compelling evidence for very simple reaction dynamics dominated by collective degrees of freedom. Invariant emission patterns of neutrons or lcp's indicate a binary first reaction stage, followed by the decay of the hot reaction products, for essentially the entire range of impact parameters. Non-evaporative light particles and cold IMF's are observed in peripheral collisions. IMF's seen in 209Bi + 136Xe collisions are possibly due to non-adiabatic neck rupture. Experimental correlations between particle multiplicity, and massive-fragment energy, deflection angle, and Z distribution suggest the presence of exchange-induced transport phenomena. In both reactions, the initially available kinetic energy is only partially damped. Together, these new observations challenge the present paradigm

  9. EA-MC Neutronic Calculations on IAEA ADS Benchmark 3.2

    The neutronics and the transmutation properties of the IAEA ADS benchmark 3.2 setup, the 'Yalina' experiment or ISTC project B-70, have been studied through an extensive amount of 3-D Monte Carlo calculations at CERN. The simulations were performed with the state-of-the-art computer code package EA-MC, developed at CERN. The calculational approach is outlined and the results are presented in accordance with the guidelines given in the benchmark description. A variety of experimental conditions and parameters are examined; three different fuel rod configurations and three types of neutron sources are applied to the system. Reactivity change effects introduced by removal of fuel rods in both central and peripheral positions are also computed. Irradiation samples located in a total of 8 geometrical positions are examined. Calculations of capture reaction rates in 129I, 237Np and 243Am samples and of fission reaction rates in 235U, 237Np and 243Am samples are presented. Simulated neutron flux densities and energy spectra as well as spectral indices inside experimental channels are also given according to benchmark specifications. Two different nuclear data libraries, JAR-95 and JENDL-3.2, are applied for the calculations

  10. Production of transplutonium elements. Overview of some national programmes

    In the last fifteen years programmes of production of transplutonium element isotopes have been well established or decided in various countries. These productions concern essentially 241Am, 243Am, 244Cm, 248Cm and 252Cf isotopes. In western world the most ambitious programme is developped by the USA in OAK RIDGE and SAVANNAH RIVER facilities for the production of transcurium elements, especially 252Cf; LOS ALAMOS, ROCKY FLATS and HANFORD facilities for 241Am production. Other western nations produced in the past or possess a permanent programme; for example kilogram amount of 241Am has been produced in RFA, while in France productions of 241Am, 243Am and 244Cm are run in routine. Various other countries are involved in the production of transplutonium isotopes but this correspond often to punctual productions. Informations related to the soviet's programme are scarce, but productions of mg quantities of transcurium elements are known. This paper gives 63 references about these programmes with special emphasis on the chemical processes

  11. Transuranium analysis methodologies for biological and environmental samples

    Analytical procedures for the most abundant transuranium nuclides in the environment (i.e., plutonium and, to a lesser extent, americium) are available. There is a lack of procedures for doing sequential analysis for Np, Pu, Am, and Cm in environmental samples, primarily because of current emphasis on Pu and Am. Reprocessing requirements and waste disposal connected with the fuel cycle indicate that neptunium and curium must be considered in environmental radioactive assessments. Therefore it was necessary to develop procedures that determine all four of these radionuclides in the environment. The state of the art of transuranium analysis methodology as applied to environmental samples is discussed relative to different sample sources, such as soil, vegetation, air, water, and animals. Isotope-dilution analysis with 243Am (239Np) and 236Pu or 242Pu radionuclide tracers is used. Americium and curium are analyzed as a group, with 243Am as the tracer. Sequential extraction procedures employing bis(2-ethyl-hexyl)orthophosphoric acid (HDEHP) were found to result in lower yields and higher Am--Cm fractionation than ion-exchange methods

  12. NMR Evidence for the 8.5 K Phase Transition in Americium Dioxide

    Tokunaga, Yo; Nishi, Tsuyoshi; Kambe, Shinsaku; Nakada, Masami; Itoh, Akinori; Homma, Yoshiya; Sakai, Hironori; Chudo, Hiroyuki

    2010-05-01

    We report here the first NMR study of americium dioxide (AmO2). More than 30 years ago, a phase transition was suggested to occur in this compound at 8.5 K based on magnetic susceptibility data, while no evidence had been obtained from microscopic measurements. We have prepared a powder sample of 243AmO2 containing 90 at. % 17O and have performed 17O NMR at temperatures ranging from 1.5 to 200 K. After a sudden drop of the 17O NMR signal intensity below 8.5 K, at 1.5 K we have observed an extremely broad spectrum covering a range of ˜14 kOe in applied field. These data provide the first microscopic evidence for a phase transition as a bulk property in this system. In addition, the 17O NMR spectrum has been found to split into two peaks in the paramagnetic state, an effect which has not been reported for actinide dioxides studied up to now. We suggest that the splitting is induced by self-radiation damage from the alpha decay of 243Am.

  13. New development of advanced superconducting electron cyclotron resonance ion source SECRAL (invited)

    Superconducting electron cyclotron resonance ion source with advance design in Lanzhou (SECRAL) is an 18-28 GHz fully superconducting electron cyclotron resonance (ECR) ion source dedicated for highly charged heavy ion beam production. SECRAL, with an innovative superconducting magnet structure of solenoid-inside-sextupole and at lower frequency and lower rf power operation, may open a new way for developing compact and reliable high performance superconducting ECR ion source. One of the recent highlights achieved at SECRAL is that some new record beam currents for very high charge states were produced by 18 GHz or 18+14.5 GHz double frequency heating, such as 1 e μA of 129Xe43+, 22 e μA of 209Bi41+, and 1.5 e μA of 209Bi50+. To further enhance the performance of SECRAL, a 24 GHz/7 kW gyrotron microwave generator was installed and SECRAL was tested at 24 GHz. Some promising and exciting results at 24 GHz with new record highly charged ion beam intensities were produced, such as 455 e μA of 129Xe27+ and 152 e μA of 129Xe30+, although the commissioning time was limited within 3-4 weeks and rf power only 3-4 kW. Bremsstrahlung measurements at 24 GHz show that x-ray is much stronger with higher rf frequency, higher rf power. and higher minimum mirror magnetic field (minimum B). Preliminary emittance measurements indicate that SECRAL emittance at 24 GHz is slightly higher that at 18 GHz. SECRAL has been put into routine operation at 18 GHz for heavy ion research facility in Lanzhou (HIRFL) accelerator complex since May 2007. The total operation beam time from SECRAL for HIRFL accelerator has been more than 2000 h, and 129Xe27+, 78Kr19+, 209Bi31+, and 58Ni19+ beams were delivered. All of these new developments, the latest results, and long-term operation for the accelerator have again demonstrated that SECRAL is one of the best in the performance of ECR ion source for highly charged heavy ion beam production. Finally the future development of SECRAL will be

  14. New development of advanced superconducting electron cyclotron resonance ion source SECRAL (invited).

    Zhao, H W; Sun, L T; Lu, W; Zhang, X Z; Guo, X H; Cao, Y; Zhao, H Y; Feng, Y C; Li, J Y; Ma, H Y; Shang, Y; Ma, B H; Wang, H; Li, X X; Xie, D Z

    2010-02-01

    Superconducting electron cyclotron resonance ion source with advance design in Lanzhou (SECRAL) is an 18-28 GHz fully superconducting electron cyclotron resonance (ECR) ion source dedicated for highly charged heavy ion beam production. SECRAL, with an innovative superconducting magnet structure of solenoid-inside-sextupole and at lower frequency and lower rf power operation, may open a new way for developing compact and reliable high performance superconducting ECR ion source. One of the recent highlights achieved at SECRAL is that some new record beam currents for very high charge states were produced by 18 GHz or 18+14.5 GHz double frequency heating, such as 1 e microA of (129)Xe(43+), 22 e microA of (209)Bi(41+), and 1.5 e microA of (209)Bi(50+). To further enhance the performance of SECRAL, a 24 GHz/7 kW gyrotron microwave generator was installed and SECRAL was tested at 24 GHz. Some promising and exciting results at 24 GHz with new record highly charged ion beam intensities were produced, such as 455 e microA of (129)Xe(27+) and 152 e microA of (129)Xe(30+), although the commissioning time was limited within 3-4 weeks and rf power only 3-4 kW. Bremsstrahlung measurements at 24 GHz show that x-ray is much stronger with higher rf frequency, higher rf power. and higher minimum mirror magnetic field (minimum B). Preliminary emittance measurements indicate that SECRAL emittance at 24 GHz is slightly higher that at 18 GHz. SECRAL has been put into routine operation at 18 GHz for heavy ion research facility in Lanzhou (HIRFL) accelerator complex since May 2007. The total operation beam time from SECRAL for HIRFL accelerator has been more than 2000 h, and (129)Xe(27+), (78)Kr(19+), (209)Bi(31+), and (58)Ni(19+) beams were delivered. All of these new developments, the latest results, and long-term operation for the accelerator have again demonstrated that SECRAL is one of the best in the performance of ECR ion source for highly charged heavy ion beam production

  15. Measurement of neutron-induced activation cross-sections using spallation source at JINR and neutronic validation of the Dubna code

    Manish Sharma; V Kumar; H Kumawat; J Adam; V S Barashenkov; S Ganesan; S Golovatiouk; S K Gupta; S Kailas; M I Krivopustov; H S Palsania; V Pronskikh; V M Tsoupko-Sitnikov; N Vladimirova; H Westmeier; W Westmeier

    2007-02-01

    A beam of 1 GeV proton coming from Dubna Nuclotron colliding with a lead target surrounded by 6 cm paraffin produces spallation neutrons. A Th-foil was kept on lead target (neutron spallation source) in a direct stream of neutrons for activation and other samples of 197Au, 209Bi, 59Co, 115In and 181Ta were irradiated by moderated beam of neutrons passing through 6 cm paraffin moderator. The gamma spectra of irradiated samples were analyzed using gamma spectrometry and DEIMOS software to measure the neutron cross-section. For this purpose neutron fluence at the positions of samples is also estimated using PREPRO software. The results of cross-sections for reactions 232Th(, ), 232Th(, 2), 197Au(, ), 197Au(, ), 197Au(, ), 59Co(, ), 59Co(, ), 181Ta(, ) and 181Ta(, ) are given in this paper. Neutronics validation of the Dubna Cascade Code is also done using cross-section data by other experiments.

  16. Status of heavy element research using GARIS at RIKEN

    A gas-filled recoil separator GARIS was installed at the RIKEN Linear Accelerator facility. Using the separator, two reactions, 208Pb(64Ni, 1n), and 209Bi(64Ni, 1n), were investigated. In the first reaction we observed fourteen α-decay chains which were assigned to be the decays starting from the isotope 271Ds(Z=110). The α-decay energies as well as the decay times coincided well with the values reported by GSI group. Existence of an isomeric state in 271Ds became clear from the present work. In the second reaction we have observed 14 α-decay chains that can be assigned to subsequent decays from 272111. The present result is the first clear confirmation for the discovery of 272111 and its α-decay products, 264Bh and 268Mt, reported previously by a GSI group. New information on their half-lives and decay energies is presented

  17. JINR Rapid Communications. Collection

    The present collection of rapid communications from JINR, Dubna, contains nine separate reports on quasi-classical description of one-nucleon transfer reactions with heavy ions, elastic and inelastic scattering in the high energy approximation, experimental study of fission and evaporation cross sections for 6 He + 209 Bi reaction, d↑ + 12 C → p + X at Θp = 0o in the region of high internal momenta in the deuteron, the Nuclotron internal targets, actively screened superconducting magnets, using of polarized target in backward elastic dp scattering, application of transputers in the data acquisition system of the INESS-ALPHA spectrometer, narrow dibaryon resonances with isotopic spin I=2. 93 refs., 27 figs., 4 tabs

  18. Alternating parity bands in doubly odd 218Ac129 and octupole instability in the light actinide region

    High-spin states of doubly odd 218Ac129 have been investigated using in-beam α, γ and conversion electron spectroscopy techniques through the 209Bi(12(13)C,3(4)n) fusion-evaporation reactions. The level scheme of 218Ac shows three interconnected, alternating parity structures, each one linked by strong E1 transitions. Two of these bands are strikingly similar to the known scheme of the isotone 217Ra and this analogy is shown to persist for the pair 220Ac, 219Ra. The relation between the structure of 218Ac and its neighbors is thoroughly discussed showing that the first signals of octupole collectivity appear for N = 129. (orig.)

  19. A 6-MJ P4 target for heavy ion inertial fusion

    A new target option for energy applications of the heavy ion inertial fusion is analyzed. It has a spherical hohlraum and is irradiated by ion beams along the directions of the zeros of the fourth Legendre polynomial P4. The target performance is simulated with a one-dimensional (1-D) three-temperature hydrodynamics code and with a two-dimensional view factor code. Its efficiency is shown to depend crucially on the structure of the hohlraum wall which, simultaneously, plays a role of the X-ray converter. For the optimized pulse power profile, a 1-D energy gain of G = 78 is calculated with the input energy of Edr = 6.1 MJ in the form of 5 GeV 209Bi ions focused on the target sphere with the outer radius of R = 6.37 mm. (author)

  20. Measuring the cross sections of heavy-metal spallation induced by deuterons with energies of 2, 2.94, and 3.5 GeV per nucleon

    Artyushenko, M. Yu.; Baldin, A. A.; Berlev, A. I.; Bukhal, O. V.; Voronko, V. A.; Gusak, K. V.; Zhuk, I. V.; Kudashkin, I. V.; Paraipan, M.; Potapenko, A. S.; Safronova, A. A.; Sotnikov, V. V.; Tyutyunnikov, S. I.

    2016-07-01

    The cross sections for the spallation of the heavy-metal nuclei 181Ta, 197Au, 207Pb, 209Bi, 232Th, and 238U induced by relativistic deuterons with energies of 2, 2.94, and 3.5 GeV per nucleon are measured using the deuteron beam from the Nuclotron accelerator of the JINR Laboratory of High Energy Physics in Dubna, Russia. The cross-section measurements employ a combined experimental technique involving the solidstate nuclear-track detectors and the activation gamma spectrometry. Adding our measurements to the database of experimental nuclear data will make it possible to test the computer codes used for selecting the parameters of the ADS-type facilities.

  1. Systematics of intermediate energy proton nonelastic and neutron total cross section

    In order to examine the Letaw intermediate energy proton nonelastic cross section systematic formula, we chose the following 12 nuclei: 12C, 16O, 27Al, 40Ca, 56Fe, 63Cu, 90Zr, 107Ag, 118Su, 181Ta, 208Pb, and 238U, which have more experimental data. In order to examine the Pearlstein intermediate energy neutron total cross section systematic formula, we chose the following 10 nuclei: 12C, 16O, 27Al, 56Fe, 63Cu, 107Ag, 181Ta, 208Pb, 209Bi, and 238U, which have more experimental data. New systematic formulas for intermediate energy proton nonelastic and neutron total cross sections are obtained. 11 refs, 22 figs

  2. Excitations of one-valence-proton, one-valence-neutron nucleus {sup 210}Bi from cold-neutron capture

    Cieplicka-Oryńczak, N. [INFN sezione di Milano, Via Celoria 16, 20133 Milano (Italy); Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342 Kraków (Poland); Fornal, B.; Szpak, B. [Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342 Kraków (Poland); Leoni, S.; Bottoni, S. [INFN sezione di Milano, Via Celoria 16, 20133 Milano (Italy); Università degli Studi di Milano, Via Celoria 16, 20133 Milano (Italy); Bazzacco, D. [Dipartimento di Fisica e Astronomia dell’Università, I-35131 Padova (Italy); INFN Sezione di Padova, I-35131 Padova (Italy); Blanc, A.; Jentschel, M.; Köster, U.; Mutti, P.; Soldner, T. [Institute Laue-Langevin, 6, rue Jules Horowitz, 38042 Grenoble Cedex 9 (France); Bocchi, G. [Università degli Studi di Milano, Via Celoria 16, 20133 Milano (Italy); France, G. de [GANIL, Bd. Becquerel, BP 55027, 14076 CAEN Cedex 05 (France); Simpson, G. [LPSC, Université Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut National Polytechnique de Grenoble, F-38026 Grenoble Cedex (France); Ur, C. [INFN Sezione di Padova, Via F. Marzolo 8, I-35131 Padova (Italy); Urban, W. [Faculty of Physics, University of Warsaw, ul. Hoża 69, 02-681, Warszawa (Poland)

    2015-10-15

    The low-spin structure of one-proton, one-neutron {sup 210}Bi nucleus was investigated in cold-neutron capture reaction on {sup 209}Bi. The γ-coincidence measurements were performed with use of EXILL array consisted of 16 HPGe detectors. The experimental results were compared to shell-model calculations involving valence particles excitations. The {sup 210}Bi nucleus offers the potential to test the effective proton-neutron interactions because most of the states should arise from the proton-neutron excitations. Additionally, it was discovered that a few states should come from the couplings of valence particles to the 3{sup −} octupole vibration in {sup 208}Pb which provides also the possibility of testing the calculations involving the core excitations.

  3. Experimental and computer simulation study of radionuclide yields in the ADT materials irradiated with intermediate energy protons

    Titarenko, Yu.E.; Shvedov, O.V.; Batyaev, V.F. [Inst. for Theoretical and Experimental Physics, B. Cheremushkinskaya, Moscow (Russian Federation)] [and others

    1998-11-01

    The results of measurements and computer simulations of the yields of residual product nuclei in {sup 209}Bi, {sup 208,207,206,nat}Pb, {sup 65,63}Cu, {sup 59}Co thin targets irradiated by 0.13, 1.2 and 1.5 GeV protons are presented. The yields were measured by direct high-precision {gamma}-spectrometry. The process was monitored by the {sup 27}Al(p,x){sup 24}Na reaction. 801 cross sections are presented and used in comparisons between the reaction yields obtained experimentally and simulated by the HETC, GNASH, LAHET, INUCL, CEM95, CASCADE, NUCLEUS, YIELDX, QMD and ALICE codes. (author)

  4. Fissility of Bi, Pb, Au, Pt, W, Ta, V, and Ti nuclei measured with 100 MeV compton back-scattered photons

    Photofission cross sections of 209 Bi, nat Pb, 197 Au, nat Pt, nat W, 181 Ta, 51 V, and nat Ti nuclei have been measured at an incident photon energy of 100 MeV using monochromatic photons produced by Compton backscattering at the ROKK-1M facility (BINP, Novosibirsk). Detection of fission fragments has been performed by means of Makrofol track-etch detectors in close contact with metallic foils of the target elements. The values of fissility at 100 MeV deduced for the targets under investigation are found to range between 10-4 and 10-2. The present results show consistency with the fissility trends calculated for 69- and 600-MeV monoenergetic photons using a formalism based on the current two-step model for intermediate-energy photofission reactions. (author). 39 refs., 4 figs., 3 tabs

  5. Nuclear photofissility in the quasi-deuteron energy region

    Paiva, E. de; Tavares, O.A.P. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Terranova, M.L. [Universita di Roma Tor Vergata (Italy). Dipt. di Scienze e Tecnologie Chimiche

    2001-04-01

    A two hundred experimental photofissility data obtained in the quasi-deuteron region ({approx} 30 - 140 MeV) of photonuclear absorption covering the target nuclei {sup 27} Al, {sup n} {sup at} Ti, {sup 51} V, {sup 154} Sm, {sup 174} Yb, {sup n} {sup at} T Hf, {sup 181} Ta, n{sup a} {sup t} W, {sup nat} Re, {sup nat} Os, {sup n} {sup a} {sup t} Pt, {sup 197} Au, {sup na} {sup t} Tl, {sup 208} Pb, {sup nat} Pb and {sup 209} Bi have been analysed in the framework of the current, two-step model for intermediate-energy photofission reactions. The incoming photon is assumed to be absorber by a neutron-proton pair (Levinger's quasi-deuteron model), followed by a mechanism of evaporation-fission competition for the excited residual nuclei. The experimental features of photofissility have been reproduced successfully by the model. (author)

  6. Excitations of one-valence-proton, one-valence-neutron nucleus 210Bi from cold-neutron capture

    The low-spin structure of one-proton, one-neutron 210Bi nucleus was investigated in cold-neutron capture reaction on 209Bi. The γ-coincidence measurements were performed with use of EXILL array consisted of 16 HPGe detectors. The experimental results were compared to shell-model calculations involving valence particles excitations. The 210Bi nucleus offers the potential to test the effective proton-neutron interactions because most of the states should arise from the proton-neutron excitations. Additionally, it was discovered that a few states should come from the couplings of valence particles to the 3− octupole vibration in 208Pb which provides also the possibility of testing the calculations involving the core excitations

  7. A subject of activation cross section library for IRAC code system

    The IRAC code system has a major activation cross section library, ACSELA94, which has been calculated using ALICE-F code on the basis of selection of geometry depended hybrid models with conditions of 9 incident particles and 136 target nuclides in the range of 1H - 209Bi. The incident energies of light ions (1H, 2H, 4He) and neutrons are from threshold energy to 150 MeV, and of heavy ions (12C, 14N, 16O, 20Ne, 40Ar) are from threshold energy to 500 MeV, respectively. To obtain the general tendency of the calculated cross section, the sum total of individual isotope production cross sections was compared with nonelastic cross section. It was found that they are in good agreement with the both in which the mass number of target nuclides is from 15 to 185. Furthermore some subjects of the cross section in ACSELA94 were found out. (author)

  8. Study of giant resonances in heavy nuclei

    The electrodisintegration cross section for181Ta,208Pb and 209Bi was measured by counting the emitted neutrons, with incident electrons in the energy range 8-22 MeV. The data was analysed using the virtual photon method, in order to obtain a multipole decomposition and the intensities of Magnetic Dipole and Electric Quadrupole, isoscalar and isovector, in the Giant Resonance. The results obtained for the isovector Giant Quadrupole Resonance are compared with the measured photodisintegration cross section, using data from Saclay and Livermore. This comparision indicates that the photodisintegration data can be well explained assuming an isovector E2 Resonance located between 120 and 130 A-1/3 MeV, with an intensity of one isovector E2 sum. (author)

  9. Decay analysis of 9Be induced reactions using stable and non deformed targets

    The pursuit of investigation of decay of compound and non compound nuclear reactions inscribes the cogitation of various processes subsequent to collision between projectile and target nuclei. Hitherto extensive studies have been devoted to understand the structure aspect associated with numerous dominant reaction mechanisms of nuclei. The Decay cross-sections of 217Rn* and 218Fr* formed in reactions 9Be+208Pb and 9Be+209Bi have been studied in framework of DCM at energies varying from Ec.m=(42.0- 67.0) MeV where both the targets have same neutron magicity (N = 126) effect. All calculations have been done for β2-deformed choice of fragmentation and optimum orientation approach

  10. Continuum spectra analysis of (p, d) and (n, d) reactions on Bi in several tens of MeV energy region

    Theoretical analyses of the double differential cross sections for proton and neutron induced deuteron pickup reactions on 209Bi are described. Neutron induced reaction cross-section data were analyzed at incident energies from about 41 MeV to 65 MeV and at 20deg laboratory angle, while proton induced reaction cross-section data were analyzed at the incident energy of 42 MeV and at 25deg laboratory angle. Spectrum regions are treated in the direct reaction scheme, i.e., several tens of MeV energy region. The double differential cross section - energy spectra were analyzed using the DWBA-based cross sections and the asymmetric Lorentzian form strength response function having energy dependent spreading width. Both the (n,d) and (p,d) spectra are fairly well reproduced by the theoretical calculations in the tens of MeV energy region. (author)

  11. A route for polonium 210 production from alpha-particle irradiated bismuth-209 target

    A method is proposed for production of polonium-210 via the 209Bi(α,3n)210 At nuclear reaction. Bombardment of a bismuth-209 target was performed with a 37 MeV alpha-particle beam that leads to the production of astatine-210 (T1/2 = 8.1 h), which decays to polonium-210. It is purified from the bismuth target matrix by employing liquid-liquid extraction using tributyl phosphate (TBP) in para-xylene from 7 M hydrochloric acid. Back extraction of polonium-210 was performed by 9 M nitric acid. This method allows to purify a tracer amount of Po-210 (2.6 x 10-13 mol) from macroscopic amount of Bi (2.8 x 10-2 mol).

  12. New result in the production and decay of an isotope, 278113, of the 113th element

    An isotope of the 113th element, i.e., 278113, was produced in a nuclear reaction with a 70Zn beam on a 209Bi target. We observed six consecutive α-decays following the implantation of a heavy particle in nearly the same position in the semiconductor detector under an extremely low background condition. The fifth and sixth decays are fully consistent with the sequential decays of 262Db and 258Lr in both decay energies and decay times. This indicates that the present decay chain consisted of 278113, 274Rg (Z=111), 270Mt (Z=109), 266Bh (Z=107), 262Db (Z=105), and 258Lr (Z=103) with firm connections. This result, together with previously reported results from 2004 and 2007, conclusively leads to the unambiguous production and identification of the isotope 278113 of the 113th element. (author)

  13. Investigation of Neutron Spectra and Transmutation of ^{129}I, ^{237}Np and Other Nuclides with 1.5 GeV Protons from the Dubna Nuclotron Using the Electronuclear Setup "Energy plus Transmutation"

    Krivopustov, M I; Balabekyan, A R; Batusov, Yu A; Bielewicz, M; Brandt, R; Chaloun, P; Chultem, D; Dwivedi, K K; Elishev, A F; Fragopoulou, M; Henzl, V; Henzlová, D; Kalinnikov, V G; Kievets, M K; Krása, A; Krizek, F; Kugler, A; Manolopoulou, Metaxia; Mariin, I I; Nourreddine, A; Odoj, R; Pavliouk, A V; Pronskikh, V S; Robotham, H; Siemon, K; Szuta, M; Stegailov, V I; Solnyshkin, A A; Sosnin, A N; Stoulos, S; Tsoupko-Sitnikov, V M; Tumendelger, T; Wojecehowski, A; Wagner, V; Wan, J S; Westmeier, W; Zamani-Valasiadou, M; Kumawat, H; Kumar, V; Zaverioukha, O S; Zhuk, I V

    2004-01-01

    Experiments which are part of the scientific program "Investigations of physical aspects of electronuclear method of energy production and transmutation for radioactive waste of atomic energetics using relativistic beams from the JINR Synchrophasotron/Nuclotron" (project "Energy plus Transmutation") are described. A large lead target surrounded by a four-section uranium blanket with total weight of 206.4 kg natural uranium was irradiated with 1.5 GeV protons from the new cryogenic accelerator Nuclotron. Radiochemical sensors were exposed to the secondary particle fluences inside and on top of the target assembly. Two long-lived radioactive waste of atomic energetics sensors ^{129}I and ^{237}Np (approximately 1 g weight each) and stable nuclides ^{27}Al, ^{59}Co, ^{127}I, ^{139}La, ^{197}Au and ^{209}Bi as well as natural and enriched uranium were used. In addition, various solid state nuclear track detectors and nuclear emulsions were exposed simultaneously. The experimental results confirm the theoretical e...

  14. Neutron-Induced Fission Cross Sections of Nuclei in the Vicinity of 208Pb at Incident Energies below 60 MeV

    Ryzhov, Igor V.; Tutin, Gennady A.; Eismont, Vilen P.; Mitryukhin, Andrey G.; Oplavin, Valery S.; Soloviev, Sergey M.; Meulders, Jean-Pierre; El Masri, Youssef; Keutgen, Thomas; Prieels, René; Nolte, Ralf

    2005-05-01

    Neutron-induced fission cross sections of 205Tl, 204, 206, 207, 208Pb, and 209Bi have been measured at incident energies of 32.8, 45.3, and 59.9 MeV. The measurements were performed at the Louvain-la-Neuve neutron beam facility using the 7Li (p, n) reaction as neutron source. Fission fragments were detected with a multi-section Frisch-gridded ionization chamber (MFGIC). Neutron fluence measurements were based on the 238U(n, f) reaction. The neutron fluence monitoring procedure was asserted by crosscheck measurement, in which the 59.9-MeV neutron beam fluence was simultaneously determined with the MFGIC and with a fission chamber monitor calibrated relative to a proton-recoil telescope.

  15. Neutron-Induced Fission Cross Sections of Nuclei in the Vicinity of 208Pb at Incident Energies below 60 MeV

    Neutron-induced fission cross sections of 205Tl, 204, 206, 207, 208Pb, and 209Bi have been measured at incident energies of 32.8, 45.3, and 59.9 MeV. The measurements were performed at the Louvain-la-Neuve neutron beam facility using the 7Li (p, n) reaction as neutron source. Fission fragments were detected with a multi-section Frisch-gridded ionization chamber (MFGIC). Neutron fluence measurements were based on the 238U(n, f) reaction. The neutron fluence monitoring procedure was asserted by crosscheck measurement, in which the 59.9-MeV neutron beam fluence was simultaneously determined with the MFGIC and with a fission chamber monitor calibrated relative to a proton-recoil telescope

  16. BISERM version 2. Nuclear data library for evaluation of radiation effects in materials induced by neutrons of intermediate

    This document describes the cross-section data library for studies of radiation effects induced by intermediate energy neutrons. The library contains hydrogen, helium-3 and helium-4 production cross-sections as well as nonelastic and total displacement cross-sections for neutrons in the energy range from threshold to 1 GeV. The cross-sections are given for 259 isotopes from 27Al to 209Bi. All this information is given in 18 compressed files plus one file with the catalogue of the data. The library was composed at the Institute of Nuclear Power Engineering in Obninsk, Russia. It is available on one PC diskette from the IAEA Nuclear Data Section costfree upon request. It requires 4 Mb of disk space after decompression. (author)

  17. Studies of giant multipole resonances with intermediate energy heavy ions

    Beene, J.R.

    1989-01-01

    The role of intermediate energy heavy ions in the study of giant multipole resonances is explored, with emphasis on gamma decay coincidence experiments. Experiments on /sup 208/Pb bombarded by 22 MeV/nucleon and 84 MeV/nucleon /sup 17/O are discussed and compared. The role of Coulomb excitation in the 84 MeV/nucleon data is emphasized and some consequences for study of isovector resonance strength are explored. A comparison of the excitation and decay of the isovector giant dipole resonance in /sup 208/Pb and /sup 209/Bi excited with 84 MeV/nucleon /sup 17/O scattering is presented. 19 refs., 15 figs., 1 tab.

  18. A study on the characteristics of beryllium isotopes by using extended optical model analyses at near-coulomb-barrier energies

    Within the framework of an extended optical model, simultaneous χ2 analyses were performed for elastic scattering and fusion cross section data for the 10Be+208Pb system at near-Coulomb-barrier energies. The result showed that both direct reaction (DR) and fusion potentials extracted from χ2 analyses separately satisfied the dispersion relation and that the expected threshold anomaly appeared in both the DR and the fusion parts. Using the extracted DR potential, we examined the effects of projectile breakup on the fusion cross-sections, σexpF . Finally, the present results for the 10Be + 208Pb system were compared with the analysis previously made for the 9Be + 208Pb and the 9Be + 209Bi systems.

  19. Extended optical model analyses of elastic scattering, direct reaction, and fusion cross sections for the 9Be+208Pb system at near-Coulomb-barrier energies

    Based on the extended optical model approach in which the polarization potential is decomposed into direct reaction (DR) and fusion parts, simultaneous χ2 analyses are performed for elastic scattering, DR, and fusion cross section data for the 9Be+208Pb system at near-Coulomb-barrier energies. Similar χ2 analyses are also performed by taking into account only the elastic scattering and fusion data as was previously done by the present authors, and the results are compared with those of the full analysis including the DR cross section data as well. We find that the analyses using only elastic scattering and fusion data can produce very consistent and reliable predictions of cross sections, particularly when the DR cross section data are incomplete. Discussions are also given on the results obtained from similar analyses made earlier for the 9Be+209Bi system

  20. Mechanism of fission of neutron-deficient actinoids nuclides

    Sueki, Keisuke; Nakahara, Hiromichi [Tokyo Metropolitan Univ., Hachioji (Japan). Faculty of Science; Tanase, Masakazu; Nagame, Yuichiro; Shinohara, Nobuo; Tsukada, Kazuaki

    1996-01-01

    A heavy ion reaction ({sup 19}F+{sup 209}Bi) is selected. The reaction produces neutron-deficient {sup 228}U which is compound nucleus with a pair of Rb(z=37) and Cs(Z=55). Energy dissipation problem of nucleus was studied by measuring the isotope distribution of two fissile nuclides. Bismuth metal evaporated on aluminium foil was irradiated by {sup 19}F with the incident energy of 105-128 MeV. We concluded from the results that the excess energy of reaction system obtained with increasing the incident energy is consumed by (1) light Rb much more than Cs and (2) about 60% of energy is given to two fission fragments and the rest 40% to the translational kinetic energy or unknown anomalous {gamma}-ray irradiation. (S.Y.)

  1. Elaboration of a model of the nuclear fragmentation and application to the method of isotopic separation of projectile fragments

    In this thesis the experimental results on the cross sections for the production of 36P in the fragmentation of 403 MeV/u 40Ar on a carbon target are presented. Furthermore some models of the nuclear fragmentation are elaborated and compared by means of experimental data for the production of gold and cerium isotopes in the reaction 12C+209Bi at 400 MeV/u, of chlorine, sulfur, aluminium, magnesium, and oxygen isotopes in the reactions 40Ar+12C at 600 MeV/u and 48Ca+9Be at 212 MeV/u, and of cobalt, manganese, vanadium, and scandium isotopes together with the charge distributions for A=43 and A=44 in the reactions 40Ar+64Cu at 2 GeV/u and 56Fe+12C at 600 MeV/u. (HSI)

  2. Development of an odd-Z-projectile reaction for heavy element synthesis: 208Pb(64Ni, n)271Ds and 208Pb(65Cu, n)272111

    Seven 271Ds decay chains were identified in the bombardment of 208Pb targets with 311.5- and 314.3-MeV 64Ni projectiles using the Berkeley Gas-filled Separator. These data, combined with previous results, provide an excitation function for this reaction. From these results, an optimum energy of 321 MeV was estimated for the production of 272111 in the reaction 208Pb(65Cu, n). One decay chain was observed, resulting in a cross section of 1.7-1.4+3.9 pb. This experiment confirms the discovery of element 111 by the Darmstadt group who used the 209Bi(64Ni, n)272111 reaction

  3. Experimental and Theoretical Study of the Residual Product Nuclide Yields in 100-2600 MeV Proton-Irradiated Thin Targets

    Titarenko, Y E; Karpikhin, E I; Zhivun, V M; Koldobsky, A B; Mulambetov, R D; Kvasova, S V; Fischenko, D V; Barashenkov, V S; Mashnik, S G; Prael, R E; Sierk, A J; Yasuda, H; Saitó, M; Titarenko, Yury E.; Batyaev, Vyacheslav F.; Karpikhin, Evgeny I.; Zhivun, Valery M.; Koldobsky, Aleksander B.; Mulambetov, Ruslan D.; Kvasova, Svetlana V.; Fischenko, Dmitry V.; Barashenkov, Vladilen S.; Mashnik, Stepan G.; Prael, Richard E.; Sierk, Arnold J.; Yasuda, Hideshi; Saito, Masaki

    2002-01-01

    The work is aimed at experimental determining and computer simulating the independent and cumulative yields of residual product nuclei in the target and structure materials of the transmutation facilities driven by high-current accelerators. The ITEP U-10 accelerator was used in 48 experiments to obtain more than 4000 values of the yields of radioactive residual product nuclei in 0.1-2.6 GeV proton-irradiated thin 182,183,184,186-W, nat-W, 56-Fe, 58-Ni, 93-Nb, 232-Th, nat-U, 99-Tc, 59-Co 63,65-Cu, nat-Hg, 208-Pb, and 27-Al targets. The results of verifying the LAHET, CEM95, CEM2k, CASCADE, CASCADE/INPE, YIELDX, HETC, INUCL, and other simulation codes are presented.

  4. Inclusive measurement of (p,πsup(-)xn) double charge exchange reactions on bismuth from threshold to 800 MeV

    The energy dependence of the total angle-integrated cross section for the production of astatine isotopes from (p,πsup(-)xn) double charge exchange reactions on bismuth (sup(209)Bi) was measured from 120 to 800 MeV using activation and radiochemical techniques. Chemical yields were estimated by direct radioassaying of sup(211)At activity in thin (approximately 1 mg/cmsup(2)), irradiated bismuth targets. Calculations of the contributions of secondary (2-step) reactions to these measured astatine yields were performed, based partially upon the observed sup(211)At activity although even at the highest energies, the contribution to products lighter than sup(207)At was negligible. These data for products with as many as 7 neutrons removed from the doubly coherent product (sup(210)At) display nearby gaussian shapes for the mass distributions of the astatine residues with the maximum occurring for about sup(204)At. The most probable momentum transfer deduced from these distributions for the initial πsup(-) production step was 335 MeV/c. The observed excitation functions display a behaviour similar to that observed for the yield of sup(210)Po from a (p,πsup(O)) reaction on sup(209)Bi, but radically different from that observed for inclusive πsup(-) reactions on a heavy nucleus. These data are discussed in terms of recent theoretical approaches to negative pion production from bismuth. In addition, a simple, schematic model is developed to treat the rapidly decreasing percentage of the total inclusive πsup(-) emission which is observed for this double charge exchange reaction. This model reflects the capacity of a nucleus to a source of internal energetic protons

  5. Development of fission micro-chambers for nuclear waste incineration studies

    The incineration of transuranic elements by neutron induced fission is a very promising way to reduce long-term radiotoxicity of nuclear waste. The Mini-Inca aims to outline the ideal physical conditions to transmute minor actinides, mainly 241-243Am, 237Np and 244-245Cm. For some actinides there are large discrepancies of neutron cross sections taken from different evaluated nuclear data libraries. These cross sections play a dominant role in transmutation systems. For instance, a factor 20 was pointed out for the 242gsAm thermal neutron capture cross section from JEF-2.2 (5500 barns) and ENDF-B/VI (250 barns) libraries. Computer simulations can lead to controversial results depending on the nuclear data library that was used. To measure the incineration rate of minor actinides, and to provide an unambiguous experimental reference, fission micro-chambers are of great interest. (author)

  6. Analysis of americium-beryllium neutron source composition using the FRAM code

    Hypes, P. A. (Philip A.); Bracken, D. S. (David S.); Sampson, Thomas E.; Taylor, W. A. (Wayne A.)

    2002-01-01

    The FRAM code was originally developed to analyze high-resolution gamma spectra from plutonium items. Its capabilities have since been expanded to include analysis of uranium spectra. The flexibility of the software also enables a capable spectroscopist to use FRAM to analyze spectra in which neither plutonium nor uranium is present in significant amounts. This paper documents the use of FRAM to determine the {sup 239}Pu/{sup 241}Am, {sup 243}Am/{sup 241}Am, {sup 237}Np/{sup 241}Am, and {sup 239}Np/{sup 241}Am ratios in americium-beryllium neutron sources. The effective specific power of each neutron source was calculated from the ratios determined by FRAM in order to determine the americium mass of each of these neutron sources using calorimetric assay. We will also discuss the use of FRAM for the general case of isotopic analysis of nonplutonium, nonuranium items.

  7. Discovery of the new element Z=117 and confirmation of 115

    The discovery of the new chemical element with atomic number Z=117 is presented. The isotopes 293117 and 294117 were produced in fusion reactions between 48Ca and 249Bk. The 249Bk was produced in the High Flux Isotope Reactor and chemically separated at Oak Ridge. Decay chains involving eleven new nuclei were identified by means of the Dubna Gas-Filled Recoil Separator. The measured decay properties show a strong rise of stability for superheavy nuclei toward N=184.The reaction 243Am+48Ca was studied at three energies. Twenty one decay chains of 288115 and one decay chain of 289115 were observed to confirm the earlier discoveries of Z=115 and 117. (authors)

  8. Actinide targets for the synthesis of super-heavy elements

    Roberto, J. B.; Alexander, C. W.; Boll, R. A.; Burns, J. D.; Ezold, J. G.; Felker, L. K.; Hogle, S. L.; Rykaczewski, K. P.

    2015-12-01

    Since 2000, six new super-heavy elements with atomic numbers 113 through 118 have been synthesized in hot fusion reactions of 48Ca beams on actinide targets. These target materials, including 242Pu, 244Pu, 243Am, 245Cm, 248Cm, 249Cf, and 249Bk, are available in very limited quantities and require specialized production and processing facilities resident in only a few research centers worldwide. This report describes the production and chemical processing of heavy actinide materials for super-heavy element research, current availabilities of these materials, and related target fabrication techniques. The impact of actinide materials in super-heavy element discovery is reviewed, and strategies for enhancing the production of rare actinides including 249Bk, 251Cf, and 254Es are described.

  9. Extended probabilistic system assessment calculations within the SKI project-90

    The probabilistic system assessment calculation reported in the SKI Project-90 final documents were restricted to the following nuclides: 14C, 129I, 135Cs, 237Np and 240Pu. In this report we have extended those calculations to another five nuclides: 79Se, 243Am, 240Pu, 93Zr and 99Tc. The execution of probabilistic assessment calculations integrated in the context of SKIs first safety analysis exercise of an hypothetic final repository for high-level nuclear waste in Sweden, was a learning experience of relevance for the conduction of probabilistic safety assessment in future exercises. Some major conclusions and viewpoints of future need related with probabilistic assessment were withdrawn from this work and are presented in our report

  10. Fission cross-section measurements on 233U and minor actinides at the CERN n-TOF facility

    Neutron-induced fission cross-sections of minor actinides have been measured at the white neutron source n-TOF at CERN, Geneva. The studied isotopes include 233U, interesting for Th/U based nuclear fuel cycles, 241,243Am and 245Cm, relevant for transmutation and waste reduction studies in new generation fast reactors (Gen-IV) or Accelerator Driven Systems. The measurements take advantage of the unique features of the n-TOF facility, namely the wide energy range, the high instantaneous neutron flux and the low background. Results for the involved isotopes are reported from ∼30 meV to around 1 MeV neutron energy. The measurements have been performed with a dedicated Fission Ionization Chamber (FIC), relative to the standard cross-section of the 235U fission reaction, measured simultaneously with the same detector. Results are here reported. (authors)

  11. A brief review of ultra-rare alpha decay detection technique

    Three approaches to the measurement of rare alpha decaying products produced in heavy-ion induced nuclear reactions are described. One is based on a chemical extraction and following deposition of the nuclides under investigation onto the surface of the detector, whereas the second one is associated with long-lived products implanted into silicon detectors by using the electromagnetic separation technique. The third approach relates with an application of real-time mode detection of correlated energy-time-position recoil-alpha sequences from 48Ca-induced nuclear reactions with actinide targets, like 242,244Pu, 245,248Cm, 243Am, and 249Cf. Namely with this technique it has became possible to provide a radical suppression of backgrounds in the full fusion (3-5n) reactions aimed at the synthesis of superheavy elements with Z = 113-118

  12. A Brief Review of Ultra-Rare Alpha Decay Detection Technique

    Tsyganov, Yu S

    2006-01-01

    Three approaches to the measurement of a rare alpha decaying products produced in heavy-ion induced nuclear reactions are described. One is based on a chemical extraction and following deposition of the nuclides under investigation onto the surface of the detector, whereas the second one is associated with long-lived products implanted into silicon detectors by using the electromagnetic separation technique. The third approach relates with an application of real-time mode detection of correlated energy-time-position recoil-alpha sequences from $^{48}$Ca-induced nuclear reactions with actinide targets, like $^{242, 244}$Pu, $^{245,248}$Cm, $^{243}$Am, and $^{249}$Cf. Namely with this technique it has became possible to provide a radical suppression of backgrounds in the full fusion (3-5$n$) reactions aimed at the synthesis of superheavy elements with Z=113-118.

  13. The solvent extraction of Am(VI) using centrifugal contactors

    An engineering-scale centrifugal contactor test bed was built at Idaho National Laboratory to perform solvent extraction testing for the partitioning of hexavalent americium. The raffinate simulant feed was spiked with 243Am and 139Ce and treated with sodium bismuthate to oxidize americium to Am(VI), filtered and contacted with 1 M DAAP/dodecane using centrifugal contactors. Extraction efficiency comparable to batch contacts was obtained, indicating for the first time that Am(VI) can be maintained under process conditions. Contrary to expectations, stripping was not as effective as expected. However, this result may actually be advantageous to process design, since a scrub step, previously thought to be impossible due to rapid Am(VI) reduction, may now be considered for future flowsheet tests. (author)

  14. Target accuracy of MA nuclear data and progress in validation by post irradiation experiments with the fast reactor 'JOYO'

    This paper presents a discussion about the target accuracy of MA nuclear data for fast reactor cycle system development, as well as the validation work on those nuclear data by PIE analyses. The PIE analyses are in progress on fuels and MA samples (237Np, 241Am, 243Am, 244Cm) irradiated at the experimental fast reactor 'JOYO'. The analysis result on the first examined MA sample suggested the necessity of re-evaluation of the isomeric ratio for 241Am capture reaction both in ENDF/B-VI and in JENDL-3.3. The above result contributes to the uncertainty-reduction both of burnup reactivity loss and of gamma energy release from fuel assemblies. (author)

  15. Up-to-date status and problems of the experimental nucleon-induced fission cross section data base at intermediate energies

    The review presents a critical consideration of all experimental data known to the authors by the end of 1998, for nuclei from 181Ta to 243Am and in the projectile energy range up to 30 GeV for protons and up to 450 MeV for neutrons. Special attention was paid to elements in the W-Bi region which are regarded as the most prospective materials for neutron-producing targets for ADS. The experimental data on nucleon-induced fission fragment angular distributions were systematized for the first time for projectile energies above 20 MeV . Data on neutron-induced fission cross sections and angular distributions are compared with proton-induced data. The large dispersion of some results and other problems of experimental data base are discussed. The possibilities of new experiments with proton beams and quasi-monoenergetic neutron beams are discussed

  16. New isotope 265Bh

    A new isotope 265Bh was produced and identified at the Sector Focus Cyclotron of the Heavy Ion Research Facility in Lanzhou. This experiment was performed via the reaction of an 243Am target with 168 MeV 26Mg ions. Identification was made by observation of correlated α -particle decays between the new isotope 265Bh and its 261Db and 257Lr daughter nuclei using a set of rotating-wheels system. A total of 8 correlated decay events of 265Bh and 4 decay events of 264Bh were observed. 265Bh decays with a 0.94 -0.31+0.70 s half-life by emission of α-particles with an average energy of 9.24 ±0.05 MeV. The half-life and α decay energy of 265Bh from this experiment are in agreement with theoretical predictions. (orig.)

  17. Excretion analysis of a case of old internal contamination with 241Am

    Two radiochemical methods were used in parallel to determine 241Am in the urine and feces of a person who had been internally contaminated with that radionuclide 25 years before. Both methods used feces and urine mineralizations. The first method comprised coprecipitation of Am together with alkaline earth metals by using bismuth phosphate, single separation on a catex, double separation on an anex, and extraction of Am into TTA in benzene. The other method consists of double coprecipitation of Am, viz., with calcium oxalate and with Fe(OH)3, followed by double separation on an anex and a single separation on a catex. In both methods, 243Am served as the recovery indicator and in the preparation of electrodeposition samples. The samples were measured by alpha spectrometry using PIPS detectors

  18. Analysis of Intermediate Energy Photonuclear Reactions

    The Cascade-Exciton Model (CEM) of nuclear reactions has been extended to describe photonuclear disintegration at intermediate energies. Using the CEM and the ORNL version of the Intranuclear Cascade Model for incident energies higher than the giant dipole resonance (GDR) region, and a group theory formalism based on the Interacting Boson Model in the GDR region, we have analyzed a variety of data for reactions induced by photons with energies up to ∼ 1.2 GeV and target-nuclei from 12C to 243Am. The contributions of different photon absorption mechanisms and the relative role of different particle production mechanisms in these reactions are discussed. 41 refs., 7 figs., 1 tab

  19. Production and Identification of New Isotope 265Bh(Z=107)

    FanHongmei; WuXiaolei; GanZaiguo; GuoJunsheng; QinZhi; LeiXiangguo; LiuHongye; GuoBin; XuHuageng; ChenRuofu; DongChengfu; ZhangFuming; WangHualei; XieChengying; FengZhaoqing; ZhenYong; SongLitao; LuoPeng; XuHushan; ZhouXiaohong; JinGenmin; RenZhongzhou

    2003-01-01

    New Isotope 265Bh was produced in bombardment of a 243Am target with 168 MeV 26Mg ions. The experiment was carried out at the Sector Focus Cyclotron of Heavy Ion Research Facility in Lanzhou in 2003. The reaction products were transported and collected by using helium-jet technique and a set of rotating wheel system. Identification was made by observation of correlated a-particles between the new isotope 265Bh and its 261Db and 257Lr daughter nuclei. A parent-daughter searching mode was used to facilitate detection of α-α correlations. A total of four pairs of PIPS detector (200mm2 active area) were used to measure the kinetic energy of a particles. The a particle energy resolution was about 40 keV for the top detectors and 100 keV for the bottom detectors because of energy degradation in the polypropylene foil.

  20. Alpha-decay properties of 266Bh

    The isotope of 266Bh was produced and identified definitely in bombardments of 243Am target with 162 MeV 26Mg ions at HIRFL. Identification was made by observation of correlated α-particle decays between the Bh isotopes and their Db and Lr daughters using a rotating wheel system. The measured α energy for 266Bh is (9.03 ± 0.08) MeV, and this value close to the 9.07 MeV for 266Bh observed in the first chain of element 113 at RIKEN. The half-life of 266Bh is (0.66)-0.26+0.59s. The Qα value derived from this experiment fits well into the general trend in a 'Qα-N systematics' for the isotopes with Z=107. (authors)

  1. MANTRA: An Integral Reactor Physics Experiment to Infer Actinide Capture Cross-sections from Thorium to Californium with Accelerator Mass Spectrometry

    G. Youinou; C. McGrath; G. Imel; M. Paul; R. Pardo; F. Kondev; M. Salvatores; G. Palmiotti

    2011-08-01

    The principle of the proposed experiment is to irradiate very pure actinide samples in the Advanced Test Reactor at INL and, after a given time, determine the amount of the different transmutation products. The determination of the nuclide densities before and after neutron irradiation will allow inference of effective neutron capture cross-sections. This approach has been used in the past and the novelty of this experiment is that the atom densities of the different transmutation products will be determined using the Accelerator Mass Spectrometry technique at the ATLAS facility located at ANL. It is currently planned to irradiate the following isotopes: 232Th, 235U, 236U, 238U, 237Np, 238Pu, 239Pu, 240Pu, 241Pu, 242Pu, 241Am, 243Am, 244Cm and 248Cm.

  2. Generation of an actinide isotopes cross section set for fast reactor calculations using data from ENDL and ENDF/B-IV

    A Bondarenko format 25-group cross section set of actinide isotopes was generated for the fuel cycle evaluation and the incineration study in fast reactor systems. Evaluated Nuclear Data Library of Lawrence Livermore Laboratory (U.S.) was used as the source data. The actinide isotopes treated are the following 28: Th-232, U-233, U-234, U-235, U-236, U-237, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242, Pu-243, Am-241, Am-242, Am-243, Cm-242, Cm-243, Cm-245, Cm-246, Cm-247, Cm-248, Bk-249, Cf-249, Cf-250, Cf-251, Cf-252 and a pseudo-fission product. ENDF/B-IV was used for U-238. The set was then collapsed to one energy group using a large LMFBR core spectrum for the comparison with other one-group sets. (author)

  3. Combined procedure using radiochemical separation of plutonium, americium and uranium radionuclides for alpha-spectrometry

    Radiochemical separation of Pu, Am and U was tested from synthetic solutions and evaporator concentrate samples from nuclear power plants for isolation of each of them for alpha-spectrometry analysis. The separation was performed by anion-exchange chromatography, extraction chromatography, using TRU resin, and precipitation techniques. The aim of the study was to develop a sensitive analytical procedure for the sequential determination of 242Pu, 238Pu, 239+240Pu, 241Am and 235,238U in radioactive wastes. 238Pu, 242Pu, 243Am and 232U were used as tracers. The measurements of α emitting radionuclides were performed by semiconductor detector that is used especially when spectrometric information is needed. For synthetic solutions the chemical recovery was based on associated iron concentration and was about 93%. (author)

  4. Updated multi-group cross sections of minor actinides with improved resonance treatment

    The study of minor actinide in transmutation reactors and other future applications makes resonance self-shielding treatment a significant issue for criticality and isotope depletion. Resonance treatment for minor actinides has been carried out by subgroup method with improved interference effect through interference correction. Subgroup data was generated using RMET21 and GENP codes along with multi-group cross section data by NJOY nuclear data processing system. Updated multi-group cross section data library for a neutron transport code nTRACER was compared with solutions from MCNPX. The resonance interaction of uranium with minor actinides has been included by modified interference treatment of interference correction in subgroup methodology. The comparison of cross sections and multiplication factor in pin and assembly problems showed significant improvement from systematic resonance treatment especially for 237Np and 243Am. (author)

  5. Measurement of the fast neutron capture cross section of 238U relative to 235U(n,f)

    The capture cross section of 238U was measured using the activation technique and 235U(n,f) as a reference cross section. Capture events were measured by detection of two prominent γ-transitions in the decay of the 239U daughter nuclide, 239Np, employing a high resolution Ge(Li) detector. The system was calibrated with samples activated in a thermal neutron flux relative to the capture cross section of gold, and with an absolutely calibrated α-emitter, 243Am, which decays to 239Np. Cross section measurements were carried out in the neutron energy range from 30 keV to 3 MeV. Emphasis was on absolute values between 150 keV and 1 MeV where the 238U(n,γ) cross section and its cross section is small. Background from fission products was found to restrict the accuracy of the measured data at energies > 1.5 MeV

  6. Preparation of americium targets for nuclear chemistry experiments at DANCE

    Using 1 gram of 241Am from LANL stocks, the purification steps required to obtain a solution of 241Am from the original material are described. Part of the purified solution was submitted for purity analysis by mass spectrometry, radiochemistry and trace metals analysis. The impurities were expected to be 239Pu and 237Np. A second fraction of this material was used for electroplating three samples onto titanium disks that were suitable for insertion into an instrument package to be placed into the DANCE detector. The purification methods used, the electroplating setup and the solutions to various problems that were encountered in making these targets are discussed. The analytical results are discussed as well as the yields from the electrodeposition process. Comparison of these yields with those from similar experiments utilizing 235U and 243Am are also discussed. (author)

  7. Neutron capture reactions at DANCE

    The Detector for Advanced Neutron Capture Experiments (DANCE) is a 4π BaF2 array consisting of 160 active detector elements. The primary purpose of the array is to perform neutron capture cross section measurements on small (> or approx.100 μg) and/or radioactive (241,243Am, neutron capture and neutron-induced fission cross sections and capture-to-fission ratio (α = σγ/σf) for 235U using a new fission-tagging detector as well as neutron capture cross sections for several astrophysics branch-point nuclei. Results from several of these measurements will be presented along with a discussion of additional physics information that can be extracted from the DANCE data

  8. AN INTEGRAL REACTOR PHYSICS EXPERIMENT TO INFER ACTINIDE CAPTURE CROSS-SECTIONS FROM THORIUM TO CALIFORNIUM WITH ACCELERATOR MASS SPECTROMETRY

    The principle of the proposed experiment is to irradiate very pure actinide samples in the Advanced Test Reactor (ATR) at INL and, after a given time, determine the amount of the different transmutation products. The determination of the nuclide densities before and after neutron irradiation will allow inference of effective neutron capture cross-sections. This approach has been used in the past and the novelty of this experiment is that the atom densities of the different transmutation products will be determined using the Accelerator Mass Spectroscopy (AMS) technique at the ATLAS facility located at ANL. It is currently planned to irradiate the following isotopes: 232Th, 235U, 236U, 238U, 237Np, 238Pu, 239Pu, 240Pu, 241Pu, 242Pu, 241Am, 243Am and 248Cm.

  9. MANTRA: An Integral Reactor Physics Experiment to Infer Actinide Capture Cross-sections from Thorium to Californium with Accelerator Mass Spectrometry

    The principle of the proposed experiment is to irradiate very pure actinide samples in the Advanced Test Reactor at INL and, after a given time, determine the amount of the different transmutation products. The determination of the nuclide densities before and after neutron irradiation will allow inference of effective neutron capture cross-sections. This approach has been used in the past and the novelty of this experiment is that the atom densities of the different transmutation products will be determined using the Accelerator Mass Spectrometry technique at the ATLAS facility located at ANL. It is currently planned to irradiate the following isotopes: 232Th, 235U, 236U, 238U, 237Np, 238Pu, 239Pu, 240Pu, 241Pu, 242Pu, 241Am, 243Am, 244Cm and 248Cm.

  10. Comparative analysis of selected aspects of the MUSE-4 experiments with the JEF-2.2 and JEFF-3.1 libraries

    This paper presents the analysis of some selected experiments of the MUSE-4 program with the ERANOS-2.1 code system using either the JEF-2.2 library or the more recent JEFF-3.1 one; focus has been given to the reactivities calculations and to the spectral indices of the MUSE-4-Reference and SC3-Pb core configurations. Both libraries provide comparable results on the keff of the Reference configuration due to large negative and positive compensating reactivity effects, whereas there is a -400 pcm effect on SC3-Pb. A perturbation analysis demonstrates that the large negative total reactivity effect in this configuration comes from the increase of the lead contribution and from the decrease of the sodium contribution. The new library improves the C/E for all the spectral indices in the fuel zone and for most of them in the lead zone except for 238U and 243Am. (authors)

  11. WWER-1000 spent fuel nuclide inventory at the Kozloduy NPP

    This paper contains a presentation and discussion of selected isotope inventory results for different types of WWER-1000 spent fuel assemblies. Nuclide inventory calculations of spent fuel assemblies at the Kozloduy NPP are routinely performed using the SCALE 4.4a computer code system. Besides the standard 17x17 ORIGEN-S library, a specific library developed at the Kozloduy NPP for each different fuel type at typical irradiation conditions is used. The evaluated concentrations of the most important isotopes - 235U, 236U, 238U, 239Pu, 240Pu, 241Pu, 242Pu - depending on burnup, are compared with fuel supplier data and with data calculated using the HELIOS-1.5 lattice code. The buildup of some other isotopes (237Np, 241Am, 243Am) is presented, too. (authors)

  12. WWER-1000 spent fuel nuclide inventory at the Kozloduy NPP

    This paper contains a presentation and discussion of selected isotope inventory results for different types of WWER-1000 spent fuel assemblies. Nuclide inventory calculations of spent fuel assemblies at Kozloduy NPP are routinely performed using the SCALE 4.4a computer code system. Besides the standard 17x17 ORIGEN-S library, a specific library developed at the Kozloduy NPP for each different fuel type at typical irradiation conditions is used. The evaluated concentrations of the most important isotopes-235U, 236U, 238U, 239Pu, 240Pu, 241Pu, 242Pu-depending on burnup, are compared with fuel supplier data and with data calculated using the HELIOS-1.5 lattice code. The buildup of some other isotopes (237Np, 241Am, 243Am) is presented, too (Authors)

  13. Rapid determination of 237Np in soil samples by multi-collector inductively-coupled plasma mass spectrometry and gamma spectrometry

    A radiochemical procedure is developed for the determination of 237Np in soil with multi-collector inductively-coupled plasma mass spectrometry (MC-ICP-MS) and gamma-spectrometry. 239Np (milked from 243Am) was used as an isotopic tracer for chemical yield determination. The neptunium in the soil is separated by thenoyl-trifluoracetone extraction from 1 M HNO3 solution after reducing Np to Np(IV) with ferrous sulfamate, and then purified with Dowex 1 x 2 anion exchange resin. 239Np in the resulting solution is measured with gamma-spectrometry for chemical yield determination while the 237Np is measured with MC-ICP-MS. Measurement results for soil samples are presented together with those for two reference samples. By comparing the determined value with the reference value of the 237Np activity concentration, the feasibility of the procedure was validated. (author)

  14. Application of high resolution inductively coupled plasma mass spectrometry to the measurement of long-lived radionuclides

    The radioactivity determination of long-lived radionuclides in environmental samples is difficult due to their low concentration and low specific activity. Limits of detection (DL) for long-lived radionuclides (99Tc, 226Ra, 232Th, 237Np, 238U, 243Am) in standard solutions using Inductively Coupled Plasma Mass Spectrometry with a double focusing mass analyzer (HR-ICP-MS) with ultrasonic nebulizer were calculated. DL of most nuclides were under the fg g-1 level. It seems that the analysis by using HR-ICP-MS has the advantage of detection for low level radio nuclides whole half life is more than 1000 y. This method was applied to 226Ra analysis in hot spring waters and 230Th in lake sediments analysis after a simple chemical separation. (author)

  15. Three sources and three components of success in detection of ultra-rare alpha decays at the Dubna Gas-Filled Recoil separator

    Tsyganov, Y S

    2015-01-01

    General philosophy of procedure of detecting rare events in the recent experiments with 48Ca projectile at the Dubna Gas-Filled Recoil Separator(DGFRS) aimed to the synthesis of superheavy elements (SHE) has been reviewed. Specific instruments and methods are under consideration. Some historical sources of the successful experiments for Z=112-118 are considered too. Special attention is paid to application of method of active correlations in heavy-ion induced complete fusion nuclear reactions. Example of application in Z=115 experiment is presented. Brief description of the 243Am + 48Ca -> 291-x115+xn experiment is presented too. Some attention is paid to the role of chemical experiments in discoveries of SHEs. The DGFRS detection/monitoring system is presented in full firstly.

  16. Neutron resonance transmission analysis of reactor spent fuel assemblies

    A method called Neutron Resonance Transmission Analysis (NRTA) is under study which would use a pulsed neutron beam for nondestructive isotopic assay of a complete spent fuel assembly. Neutrons removed from the collimated beam by absorption or scattering in the resonances of the various isotopes in the spent fuel appear as dips in the neutron transmission. The method is completely insensitive to matrix materials such as oxide, fuel cladding, and other structural members. Measurements on spent fuel buttons using the NBS linac as a pulsed neutron source demonstrate a high accuracy capability for the isotopes 234235236238U, 239240241242Pu, 241Am, 243Am, and several fission products. The NRTA method offers high speed and modest operational cost, and it can be implemented with commercially available medical or radiographic γ-ray generators adapted for neutron production. (Auth.)

  17. High-temperature X-ray diffraction studies on La1-2xCaxThxPO4(s) (x = 0, 0.25, 0.5) solid-solution

    Advanced Heavy Water Reactor (AHWR), Compact High Temperature Reactor (CHTR) and Accelerator Driven System (ADS) are being developed in India to use 232Th-233U fuel cycle. Unlike natural uranium, natural thorium contains only trace amounts of fissile material (231Th), which are insufficient to initiate a nuclear chain reaction. It can be used with 233U, 235U and 239Pu as fissile fuel. Because of it, the back end of thorium fuel cycle contains long-lived 231Pa, 229Th, 230Th and low level of minor actinides (237Np, 241Am, 243Am, 244Cm) for final disposal in geological repositories. From a geochemical point of view, monazite (LnPO4 with Ln: rare earths) is the most abundant lanthanide phosphate observed in natural samples). Such minerals appear as the major thorium source on earth, especially in several ores which contain up to 29 wt% of ThO2, 16wt% of UO2, respectively

  18. Discovery of the New Element Z=117 and Confirmation of 115

    Oganessian Yu. Ts.

    2011-10-01

    Full Text Available The discovery of the new chemical element with atomic number Z=117 is presented. The isotopes 293 117 and 294117 were produced in fusion reactions between 48Ca and 249Bk. The 249Bk was produced in the High Flux Isotope Reactor and chemically separated at Oak Ridge. Decay chains involving eleven new nuclei were identified by means of the Dubna Gas-Filled Recoil Separator. The measured decay properties show a strong rise of stability for superheavy nuclei toward N=184.The reaction 243Am+48Ca was studied at three energies. Twenty one decay chains of 288115 and one decay chain of 289115 were observed to confirm the earlier discoveries of Z=115 and 117.

  19. Determination of fission cross-section and absolute fission yields using track-cum gamma-ray spectrometric technique

    The fission cross-section of 233Pa(2nth, f) using fission track technique has been determined for the first time using thermal neutron flux of the reactor APSARA. This is important from the point of view of advance heavy water reactor (AHWR), which is to be described. On the other hand, the yields of fission products in the fast neutron induced fission of minor actinides are important from the point accelerator driven sub critical system (ADSS). In view of that, absolute yields of fission products in the fast neutron induced fission of 238U, 237Np, 238,240Pu, 243Am and 244Cm have been determined using the fission track-cum gamma-ray spectrometric technique. The total number of fission occurring in the target was estimated by track technique, whereas the activities of the fission products have been determined using gamma-ray spectrometric technique. Detailed procedure and its importance are to be discussed. (author)

  20. Monte Carlo modeling of spallation targets containing uranium and americium

    Neutron production and transport in spallation targets made of uranium and americium are studied with a Geant4-based code MCADS (Monte Carlo model for Accelerator Driven Systems). A good agreement of MCADS results with experimental data on neutron- and proton-induced reactions on 241Am and 243Am nuclei allows to use this model for simulations with extended Am targets. It was demonstrated that MCADS model can be used for calculating the values of critical mass for 233,235U, 237Np, 239Pu and 241Am. Several geometry options and material compositions (U, U + Am, Am, Am2O3) are considered for spallation targets to be used in Accelerator Driven Systems. All considered options operate as deep subcritical targets having neutron multiplication factor of k∼0.5. It is found that more than 4 kg of Am can be burned in one spallation target during the first year of operation

  1. The simultaneous neutron and photon interrogation method for fissile and non-fissile element separation in radioactive waste drums

    Measuring α-emitters such as (234,235,236,238U, 238,239,240,242,244Pu, 237Np, 241,243Am, ...), in solid radioactive waste allows us to quantify the α-activity in a drum and then to classify it. The simultaneous photon and neutron interrogation experiment (SIMPHONIE) method dealt with in this paper, combines both active neutron interrogation and induced photofission interrogation techniques simultaneously. Its purpose is to quantify fissile (235U, 239,241Pu, ...) and non-fissile (236,238U, 238,240Pu, ...) elements separately in only one measurement. This paper presents the principle of the method, the experimental setup, and the first experimental results obtained using the DGA/ETCA Linac and MiniLinatron pulsed linear electron accelerators located at Arcueil, France. First studies were carried out with U and Pu bare samples

  2. Delayed neutron spectra and their uncertainties in fission product summation calculations

    Miyazono, T.; Sagisaka, M.; Ohta, H.; Oyamatsu, K.; Tamaki, M. [Nagoya Univ. (Japan)

    1997-03-01

    Uncertainties in delayed neutron summation calculations are evaluated with ENDF/B-VI for 50 fissioning systems. As the first step, uncertainty calculations are performed for the aggregate delayed neutron activity with the same approximate method as proposed previously for the decay heat uncertainty analyses. Typical uncertainty values are about 6-14% for {sup 238}U(F) and about 13-23% for {sup 243}Am(F) at cooling times 0.1-100 (s). These values are typically 2-3 times larger than those in decay heat at the same cooling times. For aggregate delayed neutron spectra, the uncertainties would be larger than those for the delayed neutron activity because much more information about the nuclear structure is still necessary. (author)

  3. Measurement of fission cross section with pure Am-243 sample using lead slowing-down spectrometer

    Kobayashi, Katsuhei; Yamamoto, Shuji; Kai, T.; Fujita, Yoshiaki; Yamamoto, Hideki; Kimura, Itsuro [Kyoto Univ. (Japan); Shinohara, Nobuo

    1997-03-01

    By making use of back-to-back type double fission chambers and a lead slowing-down spectrometer coupled to an electron linear accelerator, the fission cross section for the {sup 243}Am(n,f) reaction has been measured relative to that for the {sup 235}U(n,f) reaction in the energy range from 0.1 eV to 10 keV. The measured result was compared with the evaluated nuclear data appeared in ENDF/B-VI and JENDL-3.2, whose evaluated data were broadened by the energy resolution function of the spectrometer. General agreement was seen between the evaluated data and the measurement except that the ENDF/B-VI data were lower in the range from 15 to 60 eV and that the JENDL-3.2 data seemed to be lower above 100 eV. (author)

  4. Investigation of neutronic behavior in a CANDU reactor with different (Am, Th, 235U)O2 fuel matrixes

    Recently thorium-based fuel matrixes are taken into consideration for nuclear waste incineration because of thorium proliferation resistance feature moreover its breeding or convertor ability in both thermal and fast reactors. In this work, neutronic influences of adding Am to (Th-235U)O2 on effective delayed neutron fraction, reactivity coefficients and burn up of a fed CANDU core has been studied using MCNPX 2.6.0 computational code. Different atom fractions of Am have been introduced in the fuel matrix to evaluate its effects on neutronic parameters of the modeled core. The computational data show that adding 2% atom fraction of Am to thorium-based fuel matrix won't noticeably change reactivity coefficients in comparison with the fuel matrix containing 1% atom fraction of Am. The use of 2% atom fraction of Am resulted in a higher delayed neutron fraction. According to the obtained data, 32.85 GWd burn up of the higher Americium-containing fuel matrix resulted in 55.2%, 26.5%, 41.9% and 2.14% depletion of 241Am, 243Am, 235U and 232Th respectively. 132.8 kg of 233U fissile element is produced after the burn up time and the nuclear core multiplication factor increases in rate of 2390 pcm. The less americium-containing fuel matrix resulted in higher depletion of 241/243Am, 235U and 232Th while the nuclear core effective multiplication factor increases in rate of 5630 pcm after the burn up time with 9.8 kg additional 233U production.

  5. Separation and activity determination of 239+240Pu, 241Am and Curium (242and244Cm) in evaporator concentrate by Alpha Spectrometry

    Alpha spectrometry analysis was used for activity determinations of Pu, Am and Cm isotopes in evaporator concentrate samples from nuclear power plants. Using a sequential procedure the first step was Pu isolation by an anion exchange column followed by an Am and Cm separation of U and Fe by a co-precipitation with oxalic acid. The precipitate was used for americium and curium separation of strontium by using a TRU resin extraction chromatography column. Due to their chemical similarities and energy difference it was seen that the simultaneous determination of 241Am, 242Cm and 243,244Cm isotopes is possible using the 243Am as tracer, once they have peaks in different region of interest (ROI) in the alpha spectrum. In this work it was used tracers, 238Pu, 243Am, 244Cm and 232U, for determination and quantification of theirs isotopes, respectively. The standard deviations for replicate analysis were calculated and for 241Am it was (1,040 ± 160 mBqKg-1), relative standard deviation 15.38%, and for 239+240Pu it was (551 +- 44 mBqKg-1), relative standard deviation 7.98%. In addition, for the 242Cm isotope the standard deviation for determinations was(75 ± 23 mBqKg-1), with the relative standard deviation 30.67% higher than for 241Am and 239+240Pu. The radiometric yields ranged from 90% to 105% and the lower limit of detection was estimated as being 2.05 mBqKg-1. (author)

  6. Nuclear Data and Measurements Series: The energy dependence of the optical-model potential for fast-neutron scattering from bismuth

    Neutron differential-elastic-scattering cross sections of bismuth were measured at 0.5 MeV intervals from 4.5 to 10.0 MeV. At each incident energy ≥40 differential values were obtained, distributed between 180 and 1600. The measured data were combined with lower-energy results previously reported from this laboratory, and others available in the literature, to provide a detailed data base extending from 1.5 to 10.0 MeV. This data base was interpreted in terms of the conventional optical-statistical model and also a model inclusive of the surface-peaked real potential predicted by the dispersion relation. Particular attention was given to the energy dependence of the volume-integral-per-nucleon of the real potential, J/sub v/, to see if there was evidence of the Fermi Surface Anomaly. In the range 3.0 to 10.0 MeV the present data indicate that dJ/sub v//dE is essentially constant, with a relatively large negative value of -6.0 to -9.0 fm3, depending on the model used in the analysis. Below 3.0 MeV, there is some evidence for a decrease in the magnitude of dJ/dE. However, the effect is very small and it is only when this trend is combined with considerations of the J/sub v/ values needed to give correct bound-state energies that evidence for the Fermi Surface Anomaly emerges. J/sub v/ and the geometry of the optical potentials found for 209Bi become equal to those needed to explain the high-energy 208Pb data at about 10.0 MeV. Since dJ/sub v//dE for the latter is smaller in magnitude than for 209Bi, a change in dJ/sub v//dE is clearly indicated near 10.0 MeV. This may effect the extrapolation of higher-energy and charged-particle potentials into the lower-energy neutron domain. 47 refs., 9 figs

  7. Odd-Z Transactinide Compound Nucleus Reactions Including the Discovery of 260Bh

    Several reactions producing odd-Z transactinide compound nuclei were studied with the 88-Inch Cyclotron and the Berkeley Gas-Filled Separator at the Lawrence Berkeley National Laboratory. The goal was to produce the same compound nucleus at or near the same excitation energy with similar values of angular momentum via different nuclear reactions. In doing so, it can be determined if there is a preference in entrance channel, because under these experimental conditions the survival portion of Swiatecki, Siwek-Wilcznska, and Wilczynski's 'Fusion By Diffusion' model is nearly identical for the two reactions. Additionally, because the same compound nucleus is produced, the exit channel is the same. Four compound nuclei were examined in this study: 258Db, 262Bh, 266Mt, and 272Rg. These nuclei were produced by using very similar heavy-ion induced-fusion reactions which differ only by one proton in the projectile or target nucleus (e.g.: 50Ti + 209Bi vs. 51V + 208Pb). Peak 1n exit channel cross sections were determined for each reaction in each pair, and three of the four pairs; cross sections were identical within statistical uncertainties. This indicates there is not an obvious preference of entrance channel in these paired reactions. Charge equilibration immediately prior to fusion leading to a decreased fusion barrier is the likely cause of this phenomenon. In addition to this systematic study, the lightest isotope of element 107, bohrium, was discovered in the 209Bi(52Cr,n) reaction. 260Bh was found to decay by emission of a 10.16 MeV alpha particle with a half-life of 35 ms. The cross section is 59 pb at an excitation energy of 15.0 MeV. The effect of the N = 152 shell is also seen in this isotope's alpha particle energy, the first evidence of such an effect in Bh. All reactions studied are also compared to model predictions by Swiatecki, Siwek-Wilcznska, and Wilczynski's 'Fusion By Diffusion' theory

  8. A study of non-elastic reaction rates for the ADS materials in the environment of spallation neutrons produced by 1.6 GeV d-beam

    For the design and modeling of Accelerator Driven sub-critical System (ADS) a detailed study of response of ADS materials to the spallation neutrons is required. For this purpose reaction rates of different reactions like (n, xn) and (n, xnyp) in 209Bi, natMo, 56Fe, natNi, 55Mn, natTi and natCo materials are determined in an experiment conducted at Nuclotron of JINR, Dubna, using 1.6 GeV d-beam in the ‘Energy+Transmutation’ set-up. Reaction rates of various (n, xn) and (n, xnyp) reactions are studied in these samples. Results of reaction rates deduced from all the gamma peaks observed in case of 209Bi (n, xn) reactions with x=3−9, natMo (n, γ), (n, 3n), (n, 6n), 56Fe (n, p), (n, p2n), (n, p4n), natNi (n, 2n), (n, 3n), (n, p), (n, d), (n, t), 55Mn (n, γ), (n, 2n), (n, 4n), natTi (n, p), (n, d), (n, t) and natCo (n, γ), (n, xn) reactions with x=2–5 along with (n, p), (n, 2p2n), (n, 2p4n) and (n, 2p6n) are presented. The measured reaction rates for all the elements show good consistency for all the reaction channels and all observed Eγ's of the product nucleus. For all the above mentioned reactions, both experimental as well as theoretical spectrum average cross-sections (σsp.av.cs) are deduced and compared. A close agreement is found between the experimental σsp.av.cs and theoretical σsp.av.cs values. - Highlights: ► (n, xn) spectrum average cross-section for seven elements are calculated. ► Comparison of theoretical and experimental spectrum average cross-sections is done. ► A close agreement is found between the experimental and theoretical cross-sections.

  9. RAPID DETERMINATION OF ACTINIDES IN URINE BY INDUCTIVELY-COUPLED PLASMA MASS SPECTROMETRY AND ALPHA SPECTROMETRY: A HYBRID APPROACH

    Maxwell, S.; Jones, V.

    2009-05-27

    A new rapid separation method that allows separation and preconcentration of actinides in urine samples was developed for the measurement of longer lived actinides by inductively coupled plasma mass spectrometry (ICP-MS) and short-lived actinides by alpha spectrometry; a hybrid approach. This method uses stacked extraction chromatography cartridges and vacuum box technology to facilitate rapid separations. Preconcentration, if required, is performed using a streamlined calcium phosphate precipitation. Similar technology has been applied to separate actinides prior to measurement by alpha spectrometry, but this new method has been developed with elution reagents now compatible with ICP-MS as well. Purified solutions are split between ICP-MS and alpha spectrometry so that long- and short-lived actinide isotopes can be measured successfully. The method allows for simultaneous extraction of 24 samples (including QC samples) in less than 3 h. Simultaneous sample preparation can offer significant time savings over sequential sample preparation. For example, sequential sample preparation of 24 samples taking just 15 min each requires 6 h to complete. The simplicity and speed of this new method makes it attractive for radiological emergency response. If preconcentration is applied, the method is applicable to larger sample aliquots for occupational exposures as well. The chemical recoveries are typically greater than 90%, in contrast to other reported methods using flow injection separation techniques for urine samples where plutonium yields were 70-80%. This method allows measurement of both long-lived and short-lived actinide isotopes. 239Pu, 242Pu, 237Np, 243Am, 234U, 235U and 238U were measured by ICP-MS, while 236Pu, 238Pu, 239Pu, 241Am, 243Am and 244Cm were measured by alpha spectrometry. The method can also be adapted so that the separation of uranium isotopes for assay is not required, if uranium assay by direct dilution of the urine sample is preferred instead

  10. Application of a gamma spectroscopy system to the measurement of neutron cross sections necessary to the development of nuclear energy; Mise au point d'un systeme de spectroscopie pour mesurer des sections efficaces neutroniques applicables a un possible developpement du nucleaire comme source d'energie

    Deruelle, O

    2002-09-01

    This work concerns the development of nuclear energy and nuclear waste management in particular. Two parts of this study can be distinguished. In the first part (theoretical), a thorium-plutonium fuel based on MOX and dedicated for PWR was investigated in order to transmute plutonium in a potentially low waste fuel cycle. It was shown that this type of fuel is not regenerative but could be used for a transition to the industrial thorium fuel cycle without building new reactors. Thanks to moderated neutron spectra and high loaded actinide mass in the core, U-233 is quickly created ({approx}300 kg/y) for a loss of about {approx}1200 kg of fissile plutonium. In the second part (experimental), we have developed and built a new reaction chamber to measure neutron cross sections of actinides by alpha-gamma spectroscopy. This experimental device (in principle transportable) was commissioned in the high flux reactor of ILL Grenoble. Neutron flux was measured by gamma spectroscopy of irradiated Al and Co samples and was found to be of the order of 6,0. 10{sup 14} n.cm{sup -2}.s{sup -1} (4%). By the irradiation of 11{mu}g of Am-243 and Pu-242, corresponding capture cross sections were measured in the thermal neutron flux at 50 deg C. These are the results: {sup 243}Am(n,{gamma}) {sup 244fond.}Am = 4,72{+-}1,42b; {sup 243}Am(n,{gamma}) {sup 244total}Am = 74,8{+-}3,25b; {sup 242}Pu (n,{gamma}){sup 243}Pu = 22,7{+-}1,09b. Uncertainties of the measurements are mostly due to the determination of the neutron flux, efficiency of the electronics and ambiguities related to the definition of the area under {alpha}-{gamma} spectra. Although our measured cross sections deviate (by 10-30%) from the corresponding values widely used in evaluated data libraries such as ENDF, JEF and JENDL, in this work we have demonstrated the feasibility and principle of our experimental method. Furthermore, the value for the 243-americium capture cross-section is in very good agreement with the last two