Space physics

espandiSpace physics

Codice identificativo insegnamento: 097486
Programma sintetico: il corso fornisce un'introduzione alla fisica dello spazio, con particolare riferimento alla magnetosfera terrestre ed alle sue interazioni con le particelle cariche. I principali argomenti trattati riguardano: cenni di astronomia (spettri stellari, evoluzione stellare, diagramma di Hertsprung-Russell, stelle compatte), la fisica del Sole e il vento solare, la fisica dei plasmi presenti nel sistema solare (cenni), la ionosfera e la magnetosfera terrestre e i fenomeni ad esse connessi, gli effetti dello spazio (radiazioni e microgravità) sui sistemi biologici e sulla strumentazione; principi fisici di alcune classi di strumenti (soprattutto telescopi, rivelatori e spettrometri) necessari per l'esplorazione dello spazio.

Physics of the Sun and the solar wind.
Evolution and classification of the stars. Nuclear processes in the stars: formation of the elements. Structure of the Sun. The core of the Sun and its atmosphere. The active Sun. Magnetic fields in the solar atmosphere. The spectrum of the solar radiation. The solar corona. The solar wind and its origin. The solar cycles. The solar system. Exoplanets.

Physics of Solar system plasmas.
Motion of charged particles in electric and magnetic fields. Drift motion. Plasma as an ion-electron gas; quasi-neutrality. Equations of conservation of mass, momentum and energy. Maxwell’s equations applied to a plasma; the magnetohydrodynamic (MHD) approximation and frozen-in flows, MHD wave modes; shock waves.

Physics of the Earth’s ionosphere.
Formation of the ionosphere; photoionisation and ionization of energetic particles. Loss mechanisms.

Physics of the Earth’s magnetosphere.
Structure and dynamics of the Earth’s magnetosphere. The geomagnetic field near the Earth; motion of charged particles in the geomagnetic field. The distant geomagnetic field; magnetopause and magnetospheric tail. The interaction of the solar wind with the magnetosphere: absorption and dissipation of the solar wind energy. Reconnection. Magnetospheric currents. Auroras phenomena: morphology and origin. Magnetic storms: origin and effects on technological systems. The magnetospheres of the outer planets.

Space effects on biological systems.
Radiation effects. Different kinds of radiations; their interactions with matter. Radiation units. Cellular damage: direct and indirect effects. Cellular and organ sensitivity to radiation. Effects of high and low doses of radiation. Effects of reduced gravity on the human body and on biological systems. Technological applications of microgravity. Methods to obtain microgravity on the Earth. Methods to simulate gravity in deep space.

Space weather and Universe observation.
Telescopes and radiotelescopes. Proportional counters. Scintillation counters. Solid state detectors. Cerenkov detectors. CCD detectors. Gamma ray telescopes. Mass spectrometers. Time of flight spectrometers. Magnetometers and electric field sensors. Methods to reveal neutrinos and cosmic rays. Researches on dark matter.

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