  This paper consists of two parts.In the first part, the scatter components of
computed tomograpahy dose profiles are modeled using various functions
including the solution to Riccati's differential equation. These scatter
functions are combined with primary components such as a trapezoidal function
and a constructed function that uses the analytic continuation of Heaviside
step function. A mathematical theory is developed in Banach space. The modeled
function is used to accurately fit data from the O-arm cone beam imaging
system. In a second part of the paper, an approach to dosimtery is developed
that shows that the results obtained from the use of a pencil shaped ion
chamber is equivalent to that from a farmer chamber. This result is verified by
presenting some preliminary experimental data measured in a 64 slice Siemens
Sensation scanner.
