.. "'"

Figure 160 Q I as a function of frequency for lead and alloys prepared from 99.9999% Pb and high-purity alloying additives [262]. (Courtesy of Lead Development Association, London.)

on the "Monte Carlo" method. The choice depends largely on the geometry and the materials involved. Some of the methods of calculation and an extensive bibliography are given in Reactor Shielding for Nuclear Engineers, edited by N. M. Schaeffer [273] and other references [272,274-276].