Abstract
In the framework of activation calculation of accelerator components with Monte Carlo methods, an unsolved problem is to take spallation products of trace elements and impurities in a bulk material into account. Due to the low probability of spallation reactions with these elements, a large number of primary particles are necessary to obtain some information about their spallation products, which is far from being converged. A new algorithm of treating high energy reactions has been implemented into MCNPX 2.5.0 to overcome these deficiencies. With this algorithm spallation reactions on all constituents of a material will be performed at each high energy interaction. This leads to the production of spallation products from all elements in a material. We will present examples on how this new methodology influences the outcome of activation calculations.
