Astatine production in a lead-bismuth target bombarded by a proton beam: a detailed study using INCL4.6-Abla07

Abstract

Liquid lead-bismuth eutectic (LBE) is often considered as a possible target in spallation neutron sources. An experiment has been performed in 2005 at ISOLDE (CERN), in which LBE has been irradiated by 1.0 and 1.4 GeV protons and isotopes of astatine, a volatile precursor of Po, have been found. Until recently no model was able to reproduce this astatine production, which is due either to double charge exchange reactions, Bi(p,π -xn)At, or to secondary reactions induced by helium nuclei. Recently, both parts of the spallation model combination INCL4-Abla have been improved leading to the new versions, INCL4.6-ABLA07. In particular, an additional mechanism to produce light and intermediate mass fragments has been added and special care has been paid to the low energy reactions. This paper first shows that all the basic features of the different reactions leading to astatine production are well predicted by the new model. The model, implemented into a beta version of MCNPX2.7 is then used to simulate the ISOLDE experiment. A very good agreement with the experimental data is observed.

The study of alpha particle induced reactions on bismuth-209 isotopes using computer code COMPLET

“…The calculated results of 209 Bi (α,xn) reaction cross-section using computer code COMPLET and the experimental data from EXFOR database are presented in tables 1 to 3 and figures 1 to 3 [10,26]. Figures 1 to 3 show the agreement between the calculated results and the experimental one.…”

“…The nuclear level density parameters which are very essential quantity, influence the shape and the height of the calculated excitation functions [10]. The default value for the level density parameter and exciton number is taken to be taken as (8, 9 ,10) and (4, 5 and 6) respectively [17,22].…”

“…The theoretical and experimental reaction cross-sections results of bismuth-209 induced by alpha particle using computer code COMPLET as seen in (figures 1 to 3 and tables 1 to 3) are compared using scientific research method [10,21]. The best level density parameter has been choosen for each reaction and radioisotope activities.…”

“…A lot of work has been done on the study of excitation function of alpha-induced reactions for various target nuclei over a wide range of energy. The comparisons between theory and experiment of 209 Bi-isotopes have not been studied well [5,10]. A theoretical analysis of the data has been carried out under the calculations based on hybrid and geometry dependent hybrid models using the computer code COMPLET which contains both compound and PE processes [9,10].…”

“…The comparisons between theory and experiment of 209 Bi-isotopes have not been studied well [5,10]. A theoretical analysis of the data has been carried out under the calculations based on hybrid and geometry dependent hybrid models using the computer code COMPLET which contains both compound and PE processes [9,10]. With this motivation the present work was undertaken to calculate the excitation function for 209 Bi with 10 MeV to 70 MeV alpha-particle energy and compare the computed results with the experimental data existing in the literature for each reactions.…”