Open Access
ND 2007
Article Number 281
Number of page(s) 4
Section Spallation measurements
Published online 17 June 2008
International Conference on Nuclear Data for Science and Technology 2007
DOI: 10.1051/ndata:07762

Volatile elements production rates in a proton-irradiated molten lead-bismuth target

Y. Tall1, S. Cormon1, M. Fallot1, Y. Foucher1, A. Guertin1, T. Kirchner1, L. Zanini2, M. Andersson2, K. Berg3, H. Frånberg2, 3, F. Gröschel2, E. Manfrin2, W. Wagner2, M. Wohlmuther2, P. Everaerts3, U. Köster3, 4, H. Ravn3, E. Noah Messomo3, C. Jost5 and Y. Kojima6

1  SUBATECH Laboratory, CNRS/IN2P3-EMN-Université, 44307 Nantes, France
2  Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
3  Paul Scherrer Institut, 5232 Villigen PSI, Switzerland 3 CERN, 1211 Genève, Switzerland
4  Institut Laue-Langevin, 38042 Grenoble, France
5  Universtät Mainz, Institut für Kernchemie, Fritz-Strassmann-Weg 2, 55128 Mainz, Germany
6  Hiroshima University, 1-4-1-Higashi-Hiroshima 7398527, Japan

Published online: 21 May 2008

The IS419 experiment at the ISOLDE facility at CERN dedicated to the measurement of production and release rates of volatile elements from an irradiated Pb/Bi target by a proton beam of 1/1.4 GeV has been completed. The release of He, Ne, Ar, Br, Kr, Cd, I, Xe, Hg, Po and At isotopes was investigated at different target temperatures, ranging from 250 °C to 600 ° C. Three experimental methods were used for the mass-separated, ionized beams: i) implantation of short- and medium-lived isotopes in a tape and on-line detection with a HPGe γ detector; ii) implantation of longer-lived isotopes in Al foils and off-line detection with a HPGe detector; iii) a Faraday Cup used mainly for stable nuclides. The results were compared with predictions from the FLUKA and MCNPX codes using different options for the intra-nuclear cascades and evaporation/fission models. Results show good agreement with calculations for Hg and for noble gases. For other elements such as iodine it is apparent that only a fraction of the produced isotopes is released. The results from FLUKA and MCNPX with the INCL4/ABLA models are in general more satisfactory than those obtained using MCNPX with the standard Bertini/Dresner model combination. Interestingly also significant yields of 204-210At isotopes were observed. At isotopes are produced either by (p, π-xn) charge exchange reactions on 209Bi or by secondary reactions involving 3He and 4He. Despite the non-release of polonium from Pb/Bi targets at typical operation temperatures, a smaller amount of highly radiotoxic Po isotopes can actually be liberated indirectly as decay daughters of the released astatine.

© CEA 2008