The Giotto RPA-Copernic plasma experiment

The RPS-Copernic plasma experiment for the Giotto mission consists of the RPA1-EESA spectrometer and the RPA2-PICCA electrostatic mass analyzer. The RPA1-EESA measures the three-dimensional distributions of electrons between 10 eV and 30 keV. The electron measurements should contribute to defining the properties of the cometary plasma and its interaction with the solar wind. The RPA2-PICCA is designed to measure the composition and the distribution of thermal cometary positive ion, including clathrate hydrates in the mass range 10 to 203 amu. This instrument should probe the interaction processes producing these ions, and provide information on the spatial distribution and chemical composition of the soldi, gas, and plasma components of the cometary environment. Such information should allow identification of parent molecule and hence give knowledge of the composition of the cometary nucleus.