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.

Removal and Containment of High-Level Radioactive Polonium From Liquid Lead-Bismuth Coolant

ABSTRACTThe channels of polonium nuclide formation in lead-bismuth target irradiated by high energy protons and secondary neutrons are considered. Under off blanket condition the activity of 200po -210Po, as well as the fission and spallation product activity are calculated for 15 MW target after 1 year operation. Polonium separation methods, including removal using alkaline extraction, vacuum sublimation, and so-called carrier method are analyzed. The engineering design for experimental apparatus to test polonium removal and containment using alkaline extraction using tellurium as a chemical analog of polonium is developed. The necessary degree of polonium removal to keep concentration below levels appropriate to meet the US and Russia safety standards is estimated. Comparative analysis of alkaline extraction and vacuum sublimation techniques from the viewpoint to achieve the necessary removal depth is carried out.

Spallation Formula Deduced from Cascade and Evaporation Theories Compared with Experiments

A semiempirical formula σ(ΔA, E0, A0), giving the sum of the spallation cross sections of the products of an isobar as a function of the mass loss Δ A, the primary energy E0 of the irradiating particle and the atomic mass number A0 of the target nucleus is deduced. The formula is intended to be used for the interpretation of the spallation product distribution in meteorites, in the atmosphere of the earth and hopefully in cosmic dust and lunar surface samples.