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Dose monitor chamber
31
Varian True beam
Transmission ionization chamber that monitors and controls
delivered dose (MU), dose rate, beam symmetry and flatness.
Utrecht 2016
•
Dose (MU) determined by summing up all
sectors, divided into two independent
channels.
•
Symmetry determined through comparisons
between left/upper and right/lower side.
•
Flatness (new on True Beam) is determined
by comparing ratios between (A+B) and I or
(C+D) and J.