Possible measurement of the gravitational acceleration of antiprotons in the presence of “strong” patch effect electrical fields
The role of electrical fields due to the patch effect in a Penning trap used to measure the Earth's gravitational accelerationg on antiprotons is analyzed. Theg measurement method is based on the study of the gravity-induced shift of the center of the radial orbits of particles stored in a Penning trap having the magnetic field perpendicular to the direction of the force of gravity. The analysis of the radial motion shows that forces originating from patch effect electrical fields about ten times stronger than the force of gravity, still allow a differential measurement ofg for antiprotons and matter particles (H−). As the precision of the measurement is affected by the particle axial energy distribution, particular care must be devoted to injecting antiprotons and H− ions into the trap with very similar initial conditions.
This paper reviews results obtained by the ESA observatory XMM-Newton in the field of Active Galactic Nuclei (AGN) research. I will cover six main areas: a) relativistic spectroscopy; b) soft excess; c) the quest for relativistic outflows; d) obscured AGN; e) scaling laws between Galactic and supermassive black holes, and f) AGN evolution and their contribution to the Cosmic X-ray Background.