Fig. 5: Electric signals measured for the three positive upward flashes.

a–c, Electric signals measured for the three positive upward flashes L1 (a), L3 (b) and N6 (c). Top: the electric field scale is given on the left y-axis and the current on the right y-axis. Bottom: X-ray signals detected by the scintillator, where each peak corresponds to the integrated X-rays energy collected during the 50 ns sampling. Events L1 and L3 correspond to events with a laser, whereas N6 corresponds to an event without a laser.