Francesco Santoli

Calibration of the IXPE instrument

IXPE scientific payload comprises of three telescopes, each composed of a mirror and a photoelectric polarimeter based on the Gas Pixel Detector design. The three focal plane detectors, together with the unit which interfaces them to the spacecraft, are named IXPE Instrument and they will be built and calibrated in Italy; in this proceeding, we will present how IXPE Instrument will be calibrated, both on-ground and in-flight. The Instrument Calibration Equipment is being finalized at INAF-IAPS in Rome (Italy) to produce both polarized and unpolarized radiation, with a precise knowledge of direction, position, energy and polarization state of the incident beam. In flight, a set of four calibration sources based on radioactive material and mounted on a filter and calibration wheel will allow for the periodic calibration of all of the three IXPE focal plane detectors independently. A highly polarized source and an unpolarized one will be used to monitor the response to polarization; the remaining two will be used to calibrate the gain through the entire lifetime of the mission.

ISA — An Accelerometer to Detect the Disturbing Accelerations Acting on the Mercury Planetary Orbiter of the BepiColombo ESA Cornerstone Mission to Mercury: on Ground Calibration

To reach the ambitious goals of the Radio Science Experiment of the BepiColombo space mission to Mercury, among which the planet structure and rotation and test Einstein’s theory of General Relativity (GR) to an unprecedented accuracy, an accelerometer has been selected to fly on‐board the MPO (Mercury Planetary Orbiter), the main spacecraft of the two to be placed around the innermost planet of our solar system around 2017. The key role of the on‐board accelerometer is to remove from the list of unknowns the non‐gravitational accelerations that disturbs the pure gravitational orbit of the MPO spacecraft in the strong radiation environment of Mercury. In this way the “corrected” orbit of the MPO may be regarded as a geodesic in the field of Mercury. Then, thanks to the very precise tracking from Earth, the possibility to study Mercury’s center‐of‐mass around the Sun and estimate several parameters related to the planet structure and verify the theory of GR. The selected accelerometer named ISA (Italian Sp...