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J. Adam K. Katovsky A. Balabekyan V. G. Kalinnikov M. I. Krivopustov H. Kumawat A. A. Solnyshkin V. I. Stegailov S. G. Stetsenko V. M. Tsoupko-Sitnikov W. Westmeier 《Pramana》2007,68(2):201-212
Target-blanket facility ‘Energy + Transmutation’ was irradiated by proton beam extracted from the Nuclotron Accelerator in
Laboratory of High Energies of Joint Institute for Nuclear Research in Dubna, Russia. Neutrons generated by the spallation
reactions of 0.7, 1.0, 1.5 and 2 GeV protons and lead target interact with subcritical uranium blanket. In the neutron field
outside the blanket, radioactive iodine, neptunium, plutonium and americium samples were irradiated and transmutation reaction
yields (residual nuclei production yields) have been determined using γ-spectroscopy. Neutron field's energy distribution
has also been studied using a set of threshold detectors. Results of transmutation studies of 129I, 237Np, 238Pu, 239Pu and 241Am are presented.
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3.
V. Wagner A. Krása M. Majerle F. Křížek O. Svoboda A. Kugler J. Adam V. M. Tsoupko-Sitnikov M. I. Krivopustov I. V. Zhuk W. Westmeier 《Pramana》2007,68(2):297-306
The set-up ‘energy plus transmutation’, consisting of a thick lead target and a natural uranium blanket, was irradiated by
relativistic proton beams with the energy from 0.7 GeV up to 2 GeV. Neutron field was measured in different places of this
set-up using different activation detectors. The possibilities of using the obtained data for benchmark studies are analyzed
in this paper. Uncertainties of experimental data are shown and discussed. The experimental data are compared with results
of simulation with MCNPX code.
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4.
J. Adam Chitra Bhatia K. Katovsky V. Kumar M. Majerle V. S. Pronskikh A. M. Khilmanovich B. A. Martsynkevich I. V. Zhuk V. M. Golovatiouk W. Westmeier A. A. Solnyshkin V. M. Tsoupko-Sitnikov A. S. Potapenko 《The European Physical Journal A - Hadrons and Nuclei》2011,47(7):1-18
Spallation neutrons produced in the collision of a 2.33GeV deuteron beam with a large lead target are moderated by a thick graphite block surrounding the target and used to activate the radioactive samples of natU and Th put at three different positions, identified as holes “a”, “b” and “c” in the graphite block. Rates of the (n, f), (n, $ \gamma$ and (n, 2n) reactions in the two samples are determined using the gamma spectrometry. The ratios of the experimental reaction rates, R (n, 2n)/R (n, f), for 232Th and natU are estimated in order to understand the role of the (n, x n) kind of reactions in Accelerator-Driven Sub-critical Systems. For the Th-sample, the ratio is ~ 54 (10)% in the case of hole “a” and ~ 95 (57)% in the case of hole “b” compared to 1.73(20)% for hole “a” and 0.710(9)% for hole “b” in the case of the natU sample. Also the ratio of fission rates in uranium to thorium, natU (n, f)/ 232Th (n, f), is ~ 11.2 (17) in the case of hole “a” and 26.8(85) in hole “b”. Similarly, the ratio 238U (n, 2n)/ 232Th (n, 2n) is 0.36(4) for hole “a” and 0.20(10) for hole “b” showing that 232Th is more prone to the (n, x n) reaction than 238U . All the experimental reaction rates are compared with the simulated ones by generating neutron fluxes at the three holes from MCNPX 2.6c and making use of the LA150 library of cross-sections. The experimental and calculated reaction rates of all the three reactions are in reasonably good agreement. The transmutation power, P norm as well as P norm/P beam of the set-up is estimated using the reaction rates of the (n, $ \gamma$ and (n, 2n) reactions for both the samples in the three holes and compared with some of the results of the “Energy plus Transmutation” set-up and TARC experiment. 相似文献
5.
A. R. Balabekyan A. S. Danagulyan J. R. Drnoyan G. H. Hovhannisyan J. Adam V. G. Kalinnikov M. I. Krivopustov V. S. Pronskikh V. I. Stegailov A. A. Solnyshkin P. Chaloun V. M. Tsoupko-Sitnikov S. G. Mashnik K. K. Gudima 《Physics of Atomic Nuclei》2006,69(9):1485-1495
We measure cross sections for residual nuclide formation in the mass range 7 ≤ A ≤ 96 caused by bombardment with protons and deuterons of 3.65-GeV/nucleon energy of enriched tin isotopes (112,118,120,124Sn). The experimental data are compared with calculations by the codes FLUKA, LAHET, CEM03, and LAQGSM03. Scaling behavior
is observed for the whole mass region of residual nuclei, showing a possible multifragmentation mechanism for the formation
of light products (7 ≤ A ≤ 30). Our analysis of the isoscaling dependence also shows a possible contribution of multifragmentation to the production
of heavier nuclides, in the mass region 40 ≤ A ≤ 80.
The text was submitted by the authors in English. 相似文献
6.
J. Adam K. Katovsky M. Majerle M. I. Krivopustov V. Kumar Chitra Bhatia Manish Sharma A. A. Solnyshkin V. M. Tsoupko-Sitnikov 《The European Physical Journal A - Hadrons and Nuclei》2010,43(2):159-173
The spallation lead target in the “Energy plus Transmutation” set-up, covered with uranium blanket, was irradiated by the
1.6GeV deuteron beam from the Nuclotron accelerator at the Joint Institute for Nuclear Research in Dubna. The neutrons generated
in the subcritical uranium blanket are used to activate the radioactive uranium and thorium samples outside the blanket. Rates
of the (n,g \gamma) , (n, f) and (n, 2n) reactions are determined for some residual nuclei. The ratio of the reaction rates R(n, 2n)/R(n, f) is estimated to be 27(9)%. Contributions of the neutrons with energy E
n > 20 MeV to the (n, f) reaction rate is ∼ 57% for 232Th and ∼ 37% for natU , respectively. To compare with the experimental results, the reaction rates are simulated by generating the neutron fluxes
employing two different models, the beam shapes by the MCNPX 2.6.c code and making use of the appropriate libraries of cross-sections.
The transmutation power of the set-up is estimated using the average (n,g \gamma) and (n, 2n) reaction rates and compared with some of the results of the TARC experiment. 相似文献
7.
F. Křížek V. Wagner J. Adam P. Čaloun V. Henzl D. Henzlová A. Krása A. Kugler M. Majerle M. I. Krivopustov V. I. Stegailov V. M. Tsoupko-Sitnikov 《Czechoslovak Journal of Physics》2006,56(3):243-252
The Neutron Activation Analysis Method was used to study neutron field in a setup consisting of a thick lead target and a
natural uranium blanket. This setup was exposed to 1.5 GeV proton beam from the Nuclotron accelerator. By means of gamma-ray
spectroscopic measurements we determined the yields of various nuclear reactions induced in the radio-chemical sensors. The
data obtained were then compared with the results of a MCNPX simulation. 相似文献
8.
A. R. Balabekyan A. S. Danagulyan J. R. Drnoyan N. A. Demekhina J. Adam V. G. Kalinnikov M. I. Krivopustov V. S. Pronskikh V. I. Stegailov A. A. Solnishkin P. Chaloun V. M. Tsoupko-Sitnikov G. Musulmanbekov 《Physics of Atomic Nuclei》2005,68(2):171-176
The cross sections for (d, xn), (d, pxn), (p, xn), and (p, pxn) reactions on enriched tin isotopes are obtained at a projectile energy of 3.65 GeV per nucleon. The yields in the energy range 0.66–8.1 GeV are analyzed with resort to experimental data obtained previously. Experimental data are compared with the results of theoretical calculations performed within the cascade-evaporation model. The dependence of the yields on the number of emitted neutrons, the projectile type, and the isotopic composition of a target is investigated. The cross sections for the (p, xpyn) reactions on a 120Sn target are presented at a primary-proton energy of 0.66 GeV. 相似文献
9.
V. Tsoupko-Sitnikov Yu. Norseev V. Khalkin 《Journal of Radioanalytical and Nuclear Chemistry》1996,205(1):75-83
Dependence upon pH of Ac and Th distribution coefficients between the cation exchange resin and buffer citrate solutions had been investigated; the optimal conditions are suggested for effective separation of the elements in this system. These results are in successful accordance with such conditions calculated on the basement of Ac and Th citrate complex formation constants.The generator method for225
Ac periodical separation from229
Th samples is developed.229
Th storage in solution between separations excludes the contamination of actinium final solution with radiolysis products and provides 100-% yield of this isotope and its high radiochemical purity. The parent nuclide loss after continuous use of the generator does not take place. 相似文献
10.
R. Brandt M. Ochs J. -S. Wan Th. Schmidt E. -J. Langrock P. Vater J. Adam V. P. Bamblevskij V. Bradnova L. K. Gelovani V. K. Kalinnikov M. I. Krivopustov B. A. Kulakov A. N. Sosnin V. P. Perelygin V. S. Pronskikh V. I. Stegailov V. M. Tsoupko-Sitnikov G. Modolo R. Odoj P. -W. Phiippen J. -C. Adloff F. Pape M. Debeauvais M. Zamani-Valassiadou S. R. Hashemi-Nezhad K. K. Dwivedi S. -L. Guo L. Li Y. -L. Wang B. Wilson 《Radiation measurements》1999,31(1-6):497-506
Experiments using 1.5 GeV, 3.7 GeV and 7.4 GeV protons from the Synchrophasotron, LHE, JINR, Dubna, Russia, on extended Pb- and U-targets were carried out using SSNTD and radiochemical sensors for the study of secondary neutron fluences. We also carried out first transmulation studies on the long-lived radwaste nuclei 129I and 237Np.
In addition, we carried out computer code simulation studies on these systems using LAHET and DCM/CEM codes. We have difficulties to understand rather large transmutation rates observed experimentally when they are compared with computer simulations. There seems to be a rather fundamental problem understanding the large transmutation rates as observed experimentally in Dubna and CERN, as compared to those theoretical computer simulations mentioned above. 相似文献