The effect of self-shielding of resonance cross sections on performance of Swiss Lotus hybrid device

The Lotus Swiss hybrid test facility was used to investigate the influence of the self-shielding of resonance cross sections on the tritium breeding and on the thorium ratios. Nucleonic analyses were performed using the transport code ONEDANT and the Monte Carlo method. It is shown that the self-shielding of resonance cross sections results in a decrease of thorium capture rate and an increase of the tritium breeding. The Monte Carlo analysis emphasizes this effect which becomes more relevant if the neutron multiplier lead is replaced by thorium or by beryllium