A particle detection system for calibrating a particle therapy machine or validating a particle therapy plan. The detector system includes one or more two-dimensional particle detection layers for receiving a particle beam and one or more compensating layers. The compensating layer(s) are configured to adjust energy loss and scatter values introduced by the one or more two-dimensional particle detection layers to match water-equivalent values. Each compensation layer is positioned adjacent a respective one of the one or more two-dimensional particle detection layers.
