AbstractID: 7592 Title: MCBEAM: A Monte Carlo Tool to Simulate Medical Accelerators
MCBEAM, an EGS4/PRESTA user code, has been developed to simulate the highenergy electron and photon beams from medical accelerators. Several basic geometric
entities, such as SLABS, CONES, BLOCKS, JAWS, and FRAMES, have been
implemented in the code. They are independent, reusable, and can be used to assemble
different accelerator configurations. The code accepts different source inputs such as the
frontal point source with a variable polar angle limit, frontal parallel source, and phasespace source. Only the PEGS4 file containing cross section data and the user input file
containing the description of the accelerator geometry, incident beam and output
requirement, are required for input. Once the code is complied, it is not necessary to
compile it again for different accelerator simulations. The user only needs to change the
input file before starting the simulation of a new accelerator model. The simulated
particle can be recorded and output at several planes of different locations. The format of
the output is the same as that used by the BEAM system with similar LATCH options. In
order to speed up the simulation for the photon beams, bremsstrahlung splitting was
employed for electron transport in the target. Simulations for Varian 2300C/D have been
performed using BEAM and MCBEAM. The results have been compared with each
other. They agreed very well. The difference is within the statistic uncertainty. Compared
with the BEAM system, MCBEAM is much smaller but fully functional for medical
accelerator simulations, and it is up to 1.5 times faster.