Carlo Studies of Neutron Penetration in Water

Monte Carlo Studies of Neutron Penetration in Water -J. W. Butler, J. F. Hall (Physics Div.) 

Approximately 20,000 neutron histories have been computed on the AVIDAC and a partial svimmary of the results obtained is presented in Tables VII and VIII. The fraction s/a is the parameter of the exponential transformation in units of the minimum total cross section in the energy range from zero to the initial energy. The lower entry in parentheses is the total number of neutron histories computed to obtain the result in each case. 

The numbers shown in Table VII are all for the case of normal. incidence. While no firm conclusions can be drawn it does appear that the values for reflection and transmission through 20 cm are fairly consistent. Values for transimission through 30 cm are quite erratic, and similar figures for 50-cm slabs (not shown here) are much worse. 

TEUNSMISSIWi AND REFLECTION OF ENERGETIC NEUTRCWS NORMAL TO WATER SLABS 

Fraction of energy reflected Fraction of energy transmitted 

---