A New Technology for Fast Two-Dimensional Detection of Proton Therapy Beams
Spatial resolution measurement for the Micromegas chamber using a beam moving across the boundary between channels 2 and 5. The lines represent the fraction of the integrated beam profile that is delivered to channel 2 (dotted) and channel 5 (solid). The data points are the integrated charge measured on the given channel relative to the charge measured with the transmission ionization chamber in the delivery nozzle. The ratio of the signal on the two channels can be used as a beam position measurement with σ = 1.1 mm.