Rosanna Rispoli, Elisabetta De Angelis, Luca Colasanti, Nello Vertolli, Stefano Orsini, Juergen Scheer, Alessandro Mura, Anna Milillo, Peter Wurz, Stefano Selci, Andrea Di Lellis, Roberto Leoni, Marco D'Alessandro, Francesco Mattioli, Sara Cibella
Microchannel plate (MCP) detectors are frequently used in space instrumentation for detecting a wide range of radiation and particles. The capability to detect non-thermal, low energy, neutral species is crucial for the Emitted Low-Energy Neutral Atoms (ELENA) sensor, which is part of the Search for Exospheric Refilling and Emitted Natural Abundances (SERENA) package on board the Mercury Planetary Orbiter (MPO) spacecraft of the BepiColombo mission of European Space Agency to Mercury, which is scheduled for launch in August 2015. ELENA is a time-of-flight sensor based on a novel concept using an ultrasonic oscillating shutter (start section) and MCP detector (stop detector). The ELENA scientific objective is to monitor the emission of neutral atoms from the surface of Mercury by detecting energetic neutral atoms in the range 10 eV to 5 keV, within 76 deg FOV, perpendicular to the S/C orbital plane. The surface is scanned due to the spacecraft motion. In particular, processes of particle release from the surface will be investigated by identifying particles released via solar wind-induced ion sputtering (with energies >1 eV to <100 eV ) as well as energetic hydrogen atoms, which are back-scattered solar wind protons, at energies of hundreds of eV. MCP absolute detection efficiency, for very low energy neutral atoms (E<30 eV ), is a crucial point for this investigation. At Messkammer für Flugzeitinstrumente und time-of-flight facility of the University of Bern, measurements on three MCP, with different coatings, have been performed providing the first data of MCP detection efficiencies in the energy range 10 eV to 1 keV.
R. Rispoli, E. De Angelis, L. Colasanti, N. Vertolli, S. Orsini, J. Scheer, A. Mura, A. Milillo, P. Wurz, S. Selci, A. M. Di Lellis, R. Leoni, M. D'Alessandro, F. Mattioli, S. Cibella
Microchannel Plates (MCP) detectors are frequently used in space instrumentation for detecting a wide range of radiation
and particles. In particular, the capability to detect non-thermal low energy neutral species is crucial for the sensor
ELENA (Emitted Low-Energy Neutral Atoms), part of the package SERENA (Search for Exospheric Refilling and
Emitted Natural Abundances) on board the BepiColombo mission of ESA to Mercury to be launched in 2015. ELENA is
a Time of Flight (TOF) sensor, based on a novel concept using an ultra-sonic oscillating shutter (Start section), which is
operated at frequencies up to 50 kHz; a MCP detector is used as a Stop detector. The scientific objective of ELENA is to
detect energetic neutral atoms in the range 10 eV – 5 keV, within 76° FOV, perpendicular to the S/C orbital plane.
ELENA will monitor the emission of neutral atoms from the whole surface of Mercury thanks to the spacecraft motion.
The major scientific objectives are the interaction between the plasma environment and the planet’s surface, the global
particle loss-rate and the remote sensing of the surface properties. In particular, surface release processes are investigated
by identifying particles released from the surface, via solar wind-induced ion sputtering (< 1eV – < 100 eV) as well as
Hydrogen back-scattered at hundreds eV. MCP absolute detection efficiency for very low energy neutral atoms (E <
30 eV) is a crucial point for this investigation. At the MEFISTO facility of the Physical Institute of the University of
Bern (CH), measurements on three different types of MCP (with and without coating) have been performed providing
the detection efficiencies in the energy range 10eV – 1keV. Outcomes from such measurements are discussed here.
ADAHELI ADvanced Astronomy for HELIophysics is a solar satellite designed to investigate the fast dynamics of
the solar photosphere and chromosphere performing visible and NIR broad-band and monochromatic observations
of selected atomic lines. ADAHELI is an Italian Space Agency (ASI) project, approved for a feasibility study
within the ASI Small Missions call. ISODY Interferometer for SOlar DYnamics is a Gregorian telescope and
its focal plane suite (FPS). The FPS is composed of a high-resolution fast acquisition system, based upon a
tandem of Fabry-Pérot interferometers operating in the visible and NIR regions on selected solar atmospheric
lines, a broad band channel, and a correlation tracker used as image stabilization system. In this contribution we
describe the Fabry-Pérot étalon prototype, based on the capacitance-stabilised concept, realized in our laboratory
to perform preliminary mechanical and optical tests with a view to a future Fabry-Pérot étalon prototype for
space application.
We have realized a novel optical microscope that uses the coherent superposition of diffused and diffracted beams. A laser emitting at 670nm is illuminating at oblique incidence the sample surface while a sharp metallic tip is partially obstructing the beam. The coherent superposition of diffracted radiation, coming from the tip sample region, and the reference beam, diffused by the whole surface, is collected in the far field during XY scan, obtained moving the sample only. The aperture between the tip, kept fixed at a working distance of the order of 20μm, and the local surface topography realizes a variable diffracting aperture, producing an intensity variations at the detector plane. We show clear images of a test structure with a resolution better than λ/10. A simple model is used and it is shown to be able to explain the obtained results.
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