TITLE:
Investigation of Scattered Radiation Dose at the Door of a Radiotherapy Vault When the Maze Intersects the Primary Beam
AUTHORS:
Sean Michael Tanny, Nicholas Niven Sperling, E. Ishmael Parsai
KEYWORDS:
Radiation Protection, Radiation Shielding, Scatter, Monte Carlo
JOURNAL NAME:
Journal of Modern Physics,
Vol.6 No.2,
February
25,
2015
ABSTRACT: NCRP 151 provides very detailed examples demonstrating the necessary
concerns for shielding a conventional radiotherapy vault with a maze where the
useful beam is parallel to the maze. However, it provides little guidance on
how to properly shield a vault with the maze-wall acting as part of a compound
primary barrier. We have modeled a new radiotherapy vault with this
configuration and assessed the additional photon shielding burden at the door
with MCNP5. MCNP simulations demonstrated an increase in overall photon
shielding burden at the door relative to calculations that only consider photon
workloads presented in NCRP 151. Two additional components of scattered radiation
are considered and methods for calculation are presented.