3.3.3 Post-Processing Codes
3.3.3.1 Data management utility (PENDATA)
Immediately following a transport calculation, a data management utility, PENDATA,
seamlessly gathers parallel stored data automatically following a parallel PENTRAN run, and
provides several options for the user in stripping results from parallel output files, including data
extractions from binary file storage which is an essential utility for a code with parallel I/O.
3.3.3.2 Dose calculation code (3-D-DOSE)
The 3-D-DOSE code, developed by Al-Basheer is used to render absorbed doses based on
photon fluence results derived from the PENTRAN transport calculations. In doing so, a
methodology for determining absorbed dose in the phantom based on photon fluence was
developed for situations where electron transport effects do not require specific treatment. CPE is
assumed to be established in a volume when the energy carried into the volume by charged
particles is balanced by the energy carried out of the volume by the charged particles.
In the example simulation in Section 3.4, the maximum energy used is 90 kV, for which
the range of the secondary electrons produced is smaller than smallest voxel dimensions used in
the model. Moreover, the atomic number of the material Z is relatively low, excluding major
production of bremsstrahlung radiation, thus depositing all the photon energy in the voxel,
achieving CPE. Consequently kerma is equal to absorbed dose in this case. We note this is not
true for regions in close proximity to the surface of the model using higher energies due to
absorbed dose buildup, where corrections for secondary electron transport may be quite
significant, especially for high energy beams. After extracting 3-D scalar fluxes from the
phantom model we apply the 3-D-DOSE code. Based on fitted mass-energy absorption
coefficients 44, Shown in Figure 3-3, and the scalar fluxes from the PENTRAN calculations, 3-D-