Figure 3

Comparison to RCF stacks at Draco (Dresden): (a) is a sketch of the setup. A pulsed solenoid was used to focus a certain design energy. (b) is the measured signal and the reconstructed signal according to the energy distribution evaluated in (c). (c) shows the final reconstructed proton spectrum. (d) is the depth dose distribution determined by I-BEAT compared to the one obtained by an RCF stack. The corresponding layers of the stack are depicted and the dose (colour coded in Gy) is evaluated over a circle of 1 cm diameter (entrance of the detector) for both the RCF stack and I-BEAT. The evaluated Gaussian profile determined by I-BEAT yields \(\,{\sigma }_{r}=3.0\pm 0.2\) mm and fits very well to the dose of the RCF stack (shown in the second film picture of the stack). The upper axis shows the corresponding proton energy of different penetration depths. The error bar of I-BEAT on the y-axis is due to the calibration of the detector and the noise of measured signal. The error bar of the RCF stack is caused by calibration uncertainties⁵⁰. The grey bar t_RCF illustrates the thickness of one RCF and thus the spatial resolution.