Measurement of aluminum activation cross section and gas production cross section for 0.4 and 3-GeV protons

To estimate the lifetime and the radiation dose of the proton beam window used in the spallation neutron source at J-PARC, it is necessary to understand the accuracy of the production cross section of 3-GeV protons. To obtain data on aluminum, the reaction cross section of aluminum was measured at the entrance of the beam dump placed in the 3-GeV proton synchrotron. Owing to the use of well-calibrated current transformers and a well-collimated beam, the present data has good accuracy. After irradiation, the cross sections of Al(p,x)7Be, Al(p,x)22Na-22 and Al(p,x)24Na were obtained by gamma-ray spectroscopy using a Ge detector. It was found that the evaluated data of JENDL/HE-2007 agree well with the current experimental data, whereas intra-nuclear cascade models (Bertini, INCL-4.6, and JAM) with the GEM statistical decay model underestimate by about 30% in general. Moreover, gas production, such as T and He, and the cross sections were measured for carbon, which was utilized as the muon production target in J-PARC. The experiment was performed with 3-GeV proton having beam power of 0.5 MW, and the gasses emitted in the process were observed using a quadrupole mass spectrometer in the vacuum line for beam transport to the mercury target. It was found that the JENDL/HE-2007 data agree well with the present experimental data

Calculation of athermal recombination corrected dpa cross sections for proton, deuteron and heavy-ion irradiations using the PHITS code

To provide the athermal recombination corrected dpa (arc-dpa) cross sections for proton, deuteron and heavy ion irradiations in the energy range from 1 MeV/u to 3 GeV/u., the defect production efficiencies for aluminium, copper and tungsten were implemented in the radiation damage model in PHITS. In general, the dpa cross section is large with increasing the number of protons of incident particle. For high-energy (around 1 GeV/u) proton and deuteron irradiation, the dpa cross section is close to that under 12C irradiation due to secondaries produced by the nuclear reaction. The ratio of arc-dpa cross section to the conventional Norgett-Robinson-Torrens dpa (NRT-dpa) cross section is around 0.2 with incident energies over 100 MeV for proton and deuteron irradiations. For the case of 12C and 48Ca, this ratio is ranged from 0.3 to 0.4 for incident beam energies below 3 GeV/u

Validation of PHITS Spallation Models from the Perspective of the Shielding Design of Transmutation Experimental Facility

The impact of different spallation models implemented in the particle transport code PHITS on the shielding design of Transmutation Experimental Facility is investigated. For 400-MeV proton incident on a lead-bismuth eutectic target, an effective dose rate at the end of a thick radiation shield (3-m-thick iron and 3-m-thick concrete) calculated by the Liège intranuclear cascade (INC) model version 4.6 (INCL4.6) coupled with the GEMcode (INCL4.6/GEM) yields about twice as high as the Bertini INC model (Bertini/GEM). A comparison with experimental data for 500-MeV proton incident on a thick lead target suggest that the prediction accuracy of INCL4.6/GEM would be better than that of Bertini/GEM. In contrast, it is found that the dose rates in beam ducts in front of targets calculated by the INCL4.6/GEMare lower than those by the Bertini/GEM. Since both models underestimate the experimental results for neutron-production doubledifferential cross sections at 180◦ for 140-MeV proton incident on carbon, iron, and gold targets, it is concluded that it is necessary to allow a margin for uncertainty caused by the spallation models, which is a factor of two, in estimating the dose rate induced by neutron streaming through a beam duct

A comprehensive study of spallation models for proton-induced spallation product yields utilized in transport calculation

In order to understand the current status of the predictive performance of spallation models and issues towards further improvement, a comprehensive study of the proton-induced spallation product yields was conducted. In this study, four kinds of the latest spallation models (i.e. INCL++/ABLA07, INCL++/GEMINI++, INCL4.6/GEM, and CEM03.03), utilized in Monte Carlo particle transport calculation, are employed, and six pieces of cross section data measured at GSI, RIKEN, and J-PARC are used for comparison. As a result, the INCL++/ABLA07 calculations are in general agreement with the GSI and RIKEN experimental data, whereas some discrepancies are observed especially in the comparisons with the J-PARC experiments. Finally, several key issues inherent in each spallation model are described

Measurement of nuclide production cross section for lead and bismuth with proton in energy range from 0.4 GeV to 3.0 GeV

For the Accelerator-Driven nuclear transmutation System (ADS), nuclide production yield estimation in a lead-bismuth target is important to manage the target. However, experimental data of nuclide production yield by spallation and high-energy fission reactions are scarce. In order to obtain the experimental data, an experiment in J-PARC using natPb and 209Bi samples were carried out. The samples were thin foils with about 0.1 mm thick and 25 mm × 25 mm square and were irradiated with protons at kinematic energy points of 0.4GeV, 2.2GeV, and 3.0 GeV. After the irradiation, the nuclide production cross section was determined by spectroscopic measurement of decay gamma-rays from the samples with HPGe detectors. In this paper, 14 nuclide production cross sections for lead and bismuth were obtained. They were compared with the calculated cross sections with various models and the evaluated one

Measurement of aluminum activation cross section and gas production cross section for 0.4 and 3-GeV protons

To estimate the lifetime and the radiation dose of the proton beam window used in the spallation neutron source at J-PARC, it is necessary to understand the accuracy of the production cross section of 3-GeV protons. To obtain data on aluminum, the reaction cross section of aluminum was measured at the entrance of the beam dump placed in the 3-GeV proton synchrotron. Owing to the use of well-calibrated current transformers and a well-collimated beam, the present data has good accuracy. After irradiation, the cross sections of Al(p,x)7Be, Al(p,x)22Na-22 and Al(p,x)24Na were obtained by gamma-ray spectroscopy using a Ge detector. It was found that the evaluated data of JENDL/HE-2007 agree well with the current experimental data, whereas intra-nuclear cascade models (Bertini, INCL-4.6, and JAM) with the GEM statistical decay model underestimate by about 30% in general. Moreover, gas production, such as T and He, and the cross sections were measured for carbon, which was utilized as the muon production target in J-PARC. The experiment was performed with 3-GeV proton having beam power of 0.5 MW, and the gasses emitted in the process were observed using a quadrupole mass spectrometer in the vacuum line for beam transport to the mercury target. It was found that the JENDL/HE-2007 data agree well with the present experimental data

Measurement of nuclide production cross section for lead and bismuth with proton in energy range from 0.4 GeV to 3.0 GeV

For the Accelerator-Driven nuclear transmutation System (ADS), nuclide production yield estimation in a lead-bismuth target is important to manage the target. However, experimental data of nuclide production yield by spallation and high-energy fission reactions are scarce. In order to obtain the experimental data, an experiment in J-PARC using natPb and 209Bi samples were carried out. The samples were thin foils with about 0.1 mm thick and 25 mm × 25 mm square and were irradiated with protons at kinematic energy points of 0.4GeV, 2.2GeV, and 3.0 GeV. After the irradiation, the nuclide production cross section was determined by spectroscopic measurement of decay gamma-rays from the samples with HPGe detectors. In this paper, 14 nuclide production cross sections for lead and bismuth were obtained. They were compared with the calculated cross sections with various models and the evaluated one

Measurement of displacement cross-sections of Nb irradiated by protons with kinetic energy range between 0.4 and 3 GeV

In high-intensity proton accelerator facilities, it is crucial to evaluate the damage of beam-interception materials and accelerator components, such as a superconducting magnet coil and cavity. The displacement per atom (dpa) is used as a damage index derived by integrating the particle flux and the displacement cross section. Although the dpa is employed as the standard, the experimental data of displacement cross section are scarce for a proton in the energy region above 20 MeV. To obtain the data for superconducting materials for high-intensity accelerators and magnets, we measured the displacement cross section of Nb for proton irradiation with a kinetic energy range between 0.4 and 3 GeV at J-PARC. The present experimental results were compared with the calculation of PHITS code and Karlsruhe Institute of Technology (KIT) evaluation using both NorgerttRobinson-Torrens (NRT) and the athermal recombination corrected dpa (arc-dpa) models. The experiment showed that the widely utilized NRT model overestimates the cross section by 50%. It is also found that the arc-dpa model shows remarkably good agreement with the present data

Nuclide production cross sections in proton-induced reactions on Bi at GeV energies

Proton-induced nuclide production cross sections for Bi at incident energies of 0.4, 1.5, and 3.0 GeV are measured with the activation method using the proton beams accelerated from the Rapid-Cycling Synchrotron of the Japan Proton Accelerator Research Complex (J-PARC). A total of 127 cross-section data are obtained. The measured data are compared with two types of Monte Carlo-based spallation models (i.e. INCL++ coupled with ABLA07 and INCL4.6 coupled with GEM), and the evaluated nuclear data library, JENDL/HE-2007. The result showed that INCL++/ABLA07 overall agrees with the experimental data, whereas INCL4.6/GEM underestimates the production of fission fragments