AC and Transient Magnetic Emissions of the Juice Ganymede Laser Altimeter

We report here on qualification and calibration test results constraining the AC magnetic emissions of the JUICE Ganymede Laser Altimeter (GALA) in the frequency range from 0.1 Hz to 50 kHz. The GALA instrument is intended to be launched in 2023 onboard ESA's JUICE spacecraft. It shall map the planetary surfaces of the Jovian moons Europa, Callisto, and Ganymede. The highest AC magnetic emissions are generated at the pulse repetition frequency of 30 Hz and their harmonics by the pump diode laser current pulses with an amplitude of 200 A and a width of 50 to 60 µs and by the load currents of the capacitor reservoirs that drive these current pulses. Additional signatures arise from currents caused by software processes.