Distortion of Thomson Parabolic-Like Proton Patterns Due to Electromagnetic Interference

Intense electromagnetic pulses (EMPs) accompany the production of plasma when a high-intensity laser irradiates a solid target. The EMP occurs both during and long after the end of the laser pulse (up to hundreds of nanoseconds) within and outside the interaction chamber, and interferes with nearby electronics, which may lead to the disruption or malfunction of plasma diagnostic devices. This contribution reports a correlation between the frequency spectrum of the EMP and the distortion of Thomson parabola tracks of protons observed at the kJ-class PALS laser facility in Prague. EMP emission was recorded using a simple flat antenna. Ions accelerated from the front side of the target were simultaneously detected by a Thomson parabola ion spectrometer. The comparison of the two signals suggests that the EMP may be considered to be the source of parabolic track distortion.