International Topical Meeting on Nuclear Research Applications and Utilization of Accelerators

4-8 May 2009, Vienna

ADS/ND-07

Spallation Reaction with Tin Isotopes

H. Kumawat and S. Kailas

Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai, India

Corresponding Author: kailas@barc.gov.in

In the recent past, liquid tin has been proposed as a coolant in fast reactor systems and as a spallation target that exhibits many favourable properties and attractive features, in terms of high boiling point, low melting point and low vapour pressure. With the recent availability of the spallation data for proton induced reactions on 112-124Sn isotopes at proton energies from 0.66 to 8.1 GeV, it is interesting to compare the production cross sections of light and heavy spallation products with the predictions of the well tested and successful computer code, CASCADE.04. The predictions from this code are consistent with the experimental data, in the mass range 7 - 96. E.g., In the case of 112Sn and for proton energy of 660 MeV, the production cross sections for the nuclei 77Br, 76Br and 74As are calculated to be 1.32 mb, 2.06 mb and 0.49 mb respectively. The corresponding experimental data are 1.6 mb, 0.8 mb and 0.21 mb respectively. Using this code, we have calculated the neutron yield for the tin isotopes. At proton energy of 1 GeV, the calculated neutron yield for 112Sn to 124Sn varies from 11.5 to 19.0 per proton. These values can be compared with the value of 26.5 per proton obtained for Pb. However, the tin isotopes in general have the added advantage over Pb-Bi eutectic in that they are free from Polonium radioactivity and α emitting rare earth nuclei like 146Sm, 148Gd, 150Gd and 154Dy produced in the spallation reaction on Pb-Bi eutectic. The range values of 1 GeV proton in Pb and Sn are 57 cms and 75 cms respectively. The heat density calculated for Sn is about 500 W/cm3/mA. The corresponding value for Pb is around 650 W/cm3/mA. This implies that Sn will be a better coolant from thermal hydraulics point of view.