BEXCO - Room A(101/102)
[CRD032] Characteristics of 9-day variations in the cosmic-ray flux with LISA Pathfinder
Galactic cosmic-ray (GCR) energy spectra observed in the inner heliosphere are modulated by interplanetary magnetic structures of solar origin on intervals of time compatible with the Sun rotation period and higher harmonics. A high counting rate particle detector aboard LISA Pathfinder allows for the measurement of galactic cosmic-ray and solar energetic particle integral fluxes above 70 MeV/n up to 6500 counts/s. Data are gathered at the Lagrangian point L1 in the Earth-Sun direction at 1.5 million km from Earth, with a sampling time of 15 s. Characteristics and energy-dependence of GCR flux depressions associated with the third harmonic of the Sun rotation period (approximately 9 days) are reported here. The possibility of using the LPF GCR observations to provide alerts for geomagnetic activity is discussed.