The energy of both the electron and positron beams are measured on a pulse by pulse basis by the Wire Imaging Synchrotron Detector (WISRD) [44]. One detector sits in each extraction line and is able to measure the beam energy by the profile of synchrotron radiation the beam emits as it is passed through an analyzing magnet. This is shown in Figure 4.13. The Wire Imaging Synchrotron Detector (WISRD) Energy Spectrometer.