# An isotropic point source emitting S o neutrons/s is placed in the center of a bare sphere of radius

An isotropic point source emitting So neutrons/s

is placed in the center of a bare sphere of radius R. The sphere is made up of

carbon (L2 = D/_a). Show that the general solution for flux inside the

sphere is given by:

where C1 and C2 are constants of

integration. Apply the boundary conditions and find the neutron flux anywhere

at r = R/2. [Hint: Start with Equation VIe.2.14 and make a change of function;

_ = _/r].