High-energy threshold reaction rates on 0.8 GeV proton-irradiated thick Pb-target

This works presents results of activation-aided determination of threshold reaction rates in 92 209Bi, natPb, 197Au, 181Ta, 169Tm, natIn, 93Nb, 64Zn, 65Cu, 63Cu, 59Co, 19F, and 12C samples and in 121 27Al samples. All the samples were aligned with the proton beam axis inside and outside the demountable 92-cm thick Pb target of 15-cm diameter assembled of 23 4-cm thick discs. The samples were placed on 12 target disks to reproduce the long axis distribution of protons and neutrons. In June 2006, the target was exposed for 18 hours to a 800-MeV proton beam extracted from the ITEP U-10 accelerator. The proton fluence and the proton beam shape were determined using the 27Al(p,x)7Be monitor reaction. The reaction rates were determined by the direct gamma-spectrometry techniques. In total, 1196 gamma-spectra have been measured, and about 1500 reaction rates determined. The measured reaction rates were simulated by the MCNPX code using the following databases: ENDF/B6 for neutrons below 20 MeV, MENDL2 for 20-100 MeV neutrons, and MENDL2P for proton cross sections up to 200 MeV. An acceptable agreement of simulations with experimental data has been found.Comment: 4 pages, 5 figures, 3 tables, only pdf file, to be published in Proc. Int. Conf. on Nucl. Data for Sci. and Technology (ND2007), Nice, France, April 22-27, 200

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

5972 independent and cumulative yields of radioactive residuals nuclei have been measured in 55 thin 206,207,208,nat-Pb and 209-Bi targets irradiated by 0.04, 0.07, 0.10, 0.15, 0.25, 0.6, 0.8, 1.2, 1.4, 1.6, and 2.6 GeV protons. Besides, 219 yields have been measured in 0.3, 0.5, 0.75, 1.0, 1.5, and 2.6 GeV proton-irradiated 56-Fe target. The protons were extracted from the ITEP U-10 synchrotron. The measured data are compared with experimental results obtained elsewhere and with theoretical calculations by LAHET, MCNPX, CEM03, LAQGSM03, CASCADE, CASCADO, and LAHETO codes. The predictive power was found to be different for each of the codes tested, but was satisfactory on the whole in the case of spallation products. At the same time, none of the codes can de-scribe well the product yields throughout the whole product mass range, and all codes must be further improved.Comment: 4 pages, 4 figures, 2 tables, only pdf file, to be published in Proc. Int. Conf. on Nucl. Data for Sci. and Technology (ND2007), Nice, France, April 22-27, 20

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

Cross-sections for radioactive nuclide production in 56Fe(p,x) reactions at 300, 500, 750, 1000, 1500, and 2600 MeV were measured using the ITEP U-10 proton accelerator. In total, 221 independent and cumulative yields of products of half-lives from 6.6 min to 312 days have been obtained via the direct-spectrometry method. The measured data have been compared with the experimental data obtained elsewhere by the direct and inverse kinematics methods and with calculations by 15 codes, namely: MCNPX (INCL, CEM2k, BERTINI, ISABEL), LAHET (BERTINI, ISABEL), CEM03 (.01, .G1, .S1), LAQGSM03 (.01, .G1, >.S1), CASCADE-2004, LAHETO, and BRIEFF. Most of our data are in a good agreement with the inverse kinematics results and disprove the results of some earlier activation measurements that were quite different from the inverse kinematics measurements. The most significant calculation-to-experiment differences are observed in the yields of the A<30 light nuclei, indicating that further improvements in nuclear reaction models are needed, and pointing out as well to a necessity of more complete measurements of such reactions.Comment: 53 pages, 9 figures, 6 tables, only pdf file, submitted to Phys. Rev.

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

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

Measurement and simulation of the cross sections for nuclide production in 93Nb and natNi targets irradiated with 0.04- to 2.6-GeV protons

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. © 2011 Pleiades Publishing, Ltd

Measurement and simulation of the cross sections for the production of 148Gd in thin natW and 181Ta targets irradiated with 0.4- to 2.6-GeV protons

The cross sections for the production of 148Gd in natW and 181Ta 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 direct α spectrometry without chemical separation. The experimental data have been compared with the data obtained at other laboratories and with the theoretical simulations of the yields on the basis of the BERTINI, ISABEL, CEM03. 02, INCL4. 2, INCL4. 5, CASCADE07, and PHITS codes. © 2011 Pleiades Publishing, Ltd