Physics Athens 2016

Beam Modifiers

 Most of the calculation time of a MCTP system is spent in the jaws and MLC (when tracking photons and electrons through high-Z materials many particles are lost, so it requires a lots of CPU time to obtain sufficient particles that manage to cross these parts)  To avoid waste of CPU time on photons and electrons tracking through MLC and other collimating devices approximations are introduced  Chen et al (2000): MCDOSE Ray-tracing based method for calculating transmission through MLC geometry (only works with virtual source model)