Neutron transport initial value problem in non-multiplying medium

The transport equation is discussed for neutron density in a non- multiplying medium assuming the initial neutron density distribution is known. The characteristics of both the medium and the neutron sources are considered to be a function of time. The existence and the uniqueness of the initial problem were proved and some of the earlier results obtained by the author were generalized. The behavior is briefly discussed of Knudsen's gas in a thermal bath. (auth)