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This paper presents the results of experimental determination and computational simulation of the independent cross sections of 178m2 Hf production in nat Ta and nat W thin targets irradiated by mono-energetic proton beams in the energy range from ∼ 0.04 up to 2.6 GeV. The cross sections were determined using the γ -spectrometry technique without chemical separation of irradiated samples. The obtained experimental results were compared with the results of simulations based on the modified CEM03.03-ext intranuclear cascade model, which allows to analyze both the cross sections of residual nuclei production and the probabilities of long-lived isomeric states formation. Verification of the isomeric yield calculation model was demonstrated based on experimental data on high-spin isomer production cross sections in 208Pb target irradiated by protons.

The paper presents the measured cumulative yields of 44 Ti for nat Cr, 56 Fe, nat Ni and 93 Nb samples irradiated by protons at the energy range 0.04–2.6 GeV. The obtained excitation functions are compared with calculations of the well-known codes: ISABEL, Bertini, INCL4.2+ABLA, INCL4.5+ABLA07, PHITS, CASCADE07 and CEM03.02. The predictive power of these codes regarding the studied nuclides is analyzed.

The paper presents the 207Bi production cross-sections measured by the direct gamma-spectrometry technique in the samples of lead enriched with isotopes 208, 207 and 206, as well as in the samples of natural lead and bismuth, irradiated by protons of 11 energies in the range from 0.04 to 2.6 GeV. The obtained experimental results are compared with the previous measurements, with the TENDL-2019 data-library evaluations and the simulated data by means of the high-energy transport codes MCNP6.1 (CEM03.03), PHITS (INCL4.6/GEM), and Geant4 (INCL++/ABLA). The observed discrepancies between model predictions and experimental data are discussed.

A variant of the target unit based on tungsten rods cooled by molten-salt coolant (alkali-metal fluorides) in a subcritical electronuclear facility is examined. The results of calculations of its main parameters are presented: the neutron yield, neutron spectrum on the lateral surface, top and bottom ends of the target, total energy release, specific energy release and induced activity. The calculations are performed using the three codes MCNPX 2.6B, SHIELD and KATRIN-2.5 and the codes ORIHET3 and DCHAIN-SP for calculating the changes in the radioactivity of the main units. The discrepancies in the parameters of the target unit of a subcritical electronuclear facility were determined by calculating the standard deviation factors. Apparently, the uncertainties in the computational results for the differential and integral parameters are due to the nuclear models and libraries in the programs used.

The cross sections for nuclide production in thin 93Nb and natNi targets irradiated by 0.04- to 2.6-GeV protons have been measured by direct γ spectrometry using two γ spectrometers with the resolutions of 1.8 and 1.7 keV in the 60Co 1332-keV γ line. As a result, 1112 yields of radioactive residual nuclei have been obtained. The 27Al(p, x)22Na reaction has been used as a monitor reaction. The experimental data have been compared with the MCNPX (BERTINI, ISABEL), CEM03.02, INCL4.2, INCL4.5, PHITS, and CASCADE07 calculations.

The cross sections for the monitor reactions 27Al(p, x)24Na, 27Al(p, x)22Na, and 27Al(p, x)7Be at 12 proton energies, 2605, 1598, 1199, 799, 600, 400, 249, 147.6, 97.2, 66.0, 44.6, and 40.8 MeV, have been determined with 72 × 72-mm square and 10.5-mm-diameter round aluminum foils. The rates of the reactions of the production of 24Na, 22Na, and 7Be in the foils in each irradiation run have been determined by γ spectrometry, whereas the number of protons transmitted through these foils has been determined using calibrated fast current transformers. The cross sections have been determined as the ratios of the corresponding reaction to the average proton fluence.

The cross sections for the production of Gd-148 in W-nat and Ta-181 targets irradiated by 0.4-, 0.6-, 0.8-, 1.2-, 1.6-, and 2.6-GeV protons at the ITEP accelerator complex have been measured by dir ...

The cross sections for nuclide production in thin 56Fe and natCr targets irradiated by 0.04–2.6-GeV protons are measured by direct γ spectrometry using two γ spectrometers with the resolutions of 1.8 and 1.7 keV for the 60Co 1332-keV γ line. As a result, 649 yields of radioactive residual product nuclei have been obtained. The 27Al(p, x)22Na reaction has been used as a monitor reaction. The experimental data are compared with the MCNPX (BERTINI, ISABEL), CEM03.02, INCL4.2, INCL4.5, PHITS, and CASCADE07 calculations.

The results of an experimental determination and computational modeling of the rates of threshold reactions on 209Bi, Pb, 197Au, 181Ta, 169Tm, In, 93Nb, 65Cu, 63Cu, 64Zn, 59Co, 27Al, 19F, and C on the external surface of and inside a thick lead target irradiated by 0.8 GeV protons are presented. The reaction rates were measured by γ spectrometry using Ge and (Ge–Li) detectors with resolution 1.8 and 2.9 keV, respectively, on the 1332 keV γ-line. Measurements of 2467 independent and cumulative threshold reaction rates were performed with 244 samples. The LAHET program was used for computational modeling of the results. The MENDL and MENDL2p libraries, the EXFOR databases, and the LAHET program were used to construct the excitation functions of the nuclides formed. The experimentally measured reaction rates are compared with the computed rates. The neutron and proton fluxes along the target, both on its external surface and in the interior volume, were calculated using the experimental threshold reaction rates and the computed cross sections of the reactions averaged over the spectrum of the neutrons and protons. The reaction rates measured inside and on the surface of a natural-lead target were used to determine the accuracy with which the target’s activity is measured.

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.

The independent and cumulative measured yields of residual products in thin lead and bismuth targets irradiated with 0.04-2.6 GeV protons are compared with results by the LAHET, CEM03, LAQGSM03, INCL+ABLA, CASCADE and YIELDX codes, in order to evaluate the predictive power of the codes in this energy region. 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. On the whole, the predictive power of all codes for the data in the fission and fragmentation product regions and, especially, at the borders between spallation and fission and between fission and fragmentation regions is much worse than in the spallation region; therefore, development of better evaporation/fission/fragmentation models is of first priority.

Experimental results obtained by determining the double-differential cross sections for neutron production in Pb, W, Zr, Cu, and Al targets irradiated with 0.8-, 1.0-, and 1.6-GeV protons are presented. The spectra of neutrons were measured at 15°, 30°, 60°, 90°, 120°, and 150° with a time-of-flight spectrometer by using a proton beam extracted from the 10-GeV synchrotron at the Institute of Theoretical and Experimental Physics (ITEP, Moscow). The neutrons are recorded with 5MAB-1F6BC501A/5L liquid scintillation detectors and NE110 solid-state scintillators. The experimental data in question are compared with the results of simulations based on the CEM97, LAHET, and CASCADE codes.

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, 186W, natW, 56Fe, 58Ni, 93Nb, 232Th, 232Th, natU, 99Tc, 59Co, 63, 65Cu, natHg, 208Pb, and 27Al targets. The results of verifying the LAHET, CEM95, CEM2k, CASCADE, CASCADE/INPE, YIELDX, HETC, INUCL, and other simulation codes are presented.

The results of experimental and computer simulation studies of the yields of residual product nuclei in Bi-209 thin targets irradiated by 130 MeV and 1.5 GeV protons are presented. The yields were measured by direct high-precision gamma-spectrometry. The gamma-spectrometer resolution was 1.8 keV in the 1332 keV line. The gamma-spectra were processed by the ASPRO code. The gamma-lines were identified, and the cross sections defined, by the SIGMA code using the GDISP radioactive database. The process was monitored by the Al-27(p,x)Na-24 reaction. Results are presented for comparisons between the 209-Bi(p,x) reaction yields obtained experimentally and simulated by the HETC, GNASH, LAHET, INUCL, CEM95, CASCADE, and ALICE codes.

Nuclide production cross sections measured at ITEP for the targets of nat-Cr, 56-Fe, nat-Ni, 93-Nb, 181-Ta, nat-W, nat-Pb, 209-Bi irradiated by protons with energies from 40 to 2600 MeV were used to estimate the predictive accuracy of several popular high-energy transport codes. A general agreement of the ITEP data with the data obtained by other groups, including the numerous GSI data measured by the inverse kinematics method was found. Simulations of the measured data were performed with the MCNPX (Bertini and ISABEL options), CEM03.02, INCL4.2+ABLA, INCL4.5+ABLA07, PHITS, and CASCADE.07 codes. Deviation factors between the calculated and experimental cross sections have been estimated for each target and for the whole energy range covered by our measurements. Two-dimensional diagrams of deviation factor values were produced for estimating the predictive power of every code for intermediate, not measured masses of nuclei-targets and bombarding energies of protons. Further improvements of all tested here codes are recommended. In addition, new measurements at ITEP of nuclide yields from a 208-Pb target irradiated by 500 MeV protons are presented. A good agreement between these new data and the GSI measurements obtained by the inverse kinematics method was found, 31 pages, 18 figures, 6 tables, only pdf, LANL Report LA-UR-11-02704, Los Alamos (2011), submitted to Phys. Rev. C

This work presents results of computer simulation of two experiments which aim at measuring the threshold activation reaction rates in 1 2 C, 1 9 F, 2 7 Al, 5 9 Co, 6 3 Cu, 6 5 Cu, 6 4 Zn, 9 3 Nb, 1 1 5 In, 1 6 9 Tm, 1 8 1 Ta, 1 9 7 Au, and thin samples placed inside and outside a 0.8 GeV proton-irradiated 4-cm thick W target and a 92-cm-thick W-Na composite target of 15 cm diameter both. In total, more than 1000 values of activation reaction were determined in both the experiments. The measured reaction rates were compared with the rates simulated by the LAHET code with the use of several nuclear databases for the respective excitation functions, namely, MENDL2 together with MENDL2P for cross sections of protons and neutrons up to 100 MeV, and with the recently developed IEAF-2001 that provides neutron cross sections up to 150 MeV. A comparison of simulation-to-experiment agreement obtained with MENDL2 and IEAF-2001 is presented. The agreement between simulation and experiment has been found general satisfactory for both databases. However, further studies should be done to improve the simulation of production of secondary protons and high-energy neutrons, as well as the high-energy neutron elastic scattering. Our results allow to conclude about the reliability of the transport codes and databases used to simulate the accelerator driven systems (ADS), particularly with Na-cooled W targets. High-energy threshold excitation functions to be used in the activation-based unfolding of neutron spectra inside the ADS can also be inferred from these results.

The work presents results of computer simulation of two experiments whose aim was measuring the threshold activation reaction rates in 12C, 19F, 27Al, 59Co, 63Cu, 65Cu, 64Zn, 93Nb, 115In, 169Tm, 181Ta, 197Au, and 209Bi thin samples placed inside and outside a 0.8‐GeV proton‐irradiated 4‐cm thick W target and a 92‐cm thick W‐Na composite target of 15‐cm diameter both. In total, more than 1000 values of activation reaction were determined in both experiments. The measured reaction rates were compared with the rates simulated by the LAHET code with the use of two nuclear databases for the respective excitation functions, namely, MENDL2/2P for neutron/proton cross sections up to 100 MeV, and the recently developed IEAF‐2001 that provides neutron cross sections up to 150MeV. Here, we present a comparison of the simulation‐to‐experiment agreement obtained using MENDL2 and IEAF‐2001. The agreement between simulation and experiment has been found general satisfactory for both of the databases. High‐energy thresho...

Spallation and fission residues produced by the proton irradiation of 206Pb, 207Pb, and 208Pb targets at energies from 0.15 up to 2.6 GeV have been studied recently at ITEP. These data allow testing various versions of the intranuclear cascade models widely used for simulation of spallation product yields. The main differences between codes are briefly reviewed. Modifications of the LAHET and CASCADO codes, which are required to reduce the deviations from experimental data, are discussed.

More than 5500 independent and cumulative yields of radioactive residual product nuclides with lifetimes ranging from 13.2 min (187Re) to 31.55 years (207Bi) are measured in 208, 207, 206, natPb and 209Bi thin targets irradiated by 0.04, 0.07, 0.10, 0.15, 0.25, 0.40, 0.60, 0.80, 1.20, 1.60, and 2.60 GeV external proton beams from the ITEP U10 accelerator. The measured yields are compared with results by the LAHET (Bertini and ISABEL options), CEM03, LAQGSM03, INCL4+ABLA, CASCADE, CASCADE‐2004, CASCADO, and the LAHETO codes, in order to evaluate their predictive powers in this energy region. 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. On the whole, the predictive power of all codes for the data in the fission and fragmentation product regions and, especially, at the borders between sp...

114 cross sections for nuclide production in a 1.0 GeV proton-irradiated thin 208Pb target have been measured by the direct gamma spectrometry method using a high-resolution Ge detector. The gamma spectra were processed by the GENIE-2000 code. The ITEP-developed SIGMA code was used together with the PCNUDAT nuclear decay database to identify the gamma lines and to determine the cross sections. The 27Al(p,x)22Na reaction was used to monitor the proton flux. Results of a feasibility study of the auxiliary 27Al(p,x)24Na and 27Al(p,x)7Be monitor reactions in the 0.07-2.6 GeV proton-energy range are presented as well. Most of the experimental data have been analyzed by the LAHET (with ISABEL and Bertini options), CEM95, CEM2k, INUCL, CASCADE, CASCADE/INPE, and YIELDX codes that simulate hadron-nucleus interactions.

Considering the prospects of using the W-Na target assemblies in ADS facilities, the experiments were made to study the nuclear-physics characteristics of W and Na, and the composite structures thereof in their interactions with 0.8-GeV and 1.6-GeV protons. The neutron and proton-induced reaction rates were measured inside, and on the surface of, a cylinder-shaped heterogeneous W-Na assembly together with the double-differential spectra of secondary neutrons emitted from different-depth W and Na discs. The measurement results were simulated by the LAHET, CEM2k, and KASKAD-S codes in terms of the latest versions of nuclear databases., Comment: Proc. Int. Conf. on Nuclear Data for Science and Technology (ND2001), October 7-12, 2001, Tsukuba, Ibaraki, Japan, 4 pages, 5 figures, only pdf file

Experimental data on the yields of groups of delayed neutrons are of interest for two reasons. First, the values of these yields are independent nuclear constants, which are very important in practice. Second, comparison of the experimentally determined values of yields of groups of delayed neutrons with predictive estimates, obtained with the aid of computational sets of independent fission yields, allows the consistency of these sets to be judged. The sensitivity of this method of checking is fairly high (at least at the level of the significance of parity effects in the charge distributions of the fission products [I]).

Organization of the external fuel cycles in nuclear power requires that the radiative capture cross section of /sup 236/U nuclei for neutrons with an energy ranging from several kiloelectron-volts to megaelectron-volts be estimated with an error of under 4%. From this point of view the available information about sigma/sub n,..gamma../ is unsatisfactory since in actual fact in the range 0.5-5 MeV it is based on two groups of data that at times differ by a factor of more than two. The main objective of this work was to compare the values we obtained for sigma/sub n,..gamma../ (/sup 236/U) with the data of both groups in order to determine the degree of their relative reliability