NSSDCA ID: 2018-080A-08
Mission Name: BepiColomboThe Search for Exosphere Refilling and Emitted Neutral Abundances (SERENA) experiment comprises a suite of instruments designed to study how gas interacts within and between various regions of Mercury and its cosmic environment (its surface, exosphere, magnetosphere, the solar wind). There are four instruments in the suite, working in tandem. The primary science objectives are to study: chemical and elemental composition of the exosphere; neutral gas density profiles and asymmetries; exo-ionosphere composition; exo-ionosphere spatial and energy distribution; ion precipitation rate; surface emission rate and release processes (both neutrals and ions); and particle loss rate from Mercury's environment. Other objectives include: Remote sensing of the surface composition; profiling the magnetosphere structure and dynamics; observing planetary response to solar wind variations; ENA imaging applications for comparative solar-planetary relationships; and measuring heavy ion sputtering products.
There are four instruments comprising the SERENA suite. The Emitted Low Energy Neutral Atoms (ELENA) instrument is a neutral particle camera measuring neutral particle release from the surface. It can measure particles with energies between 20 eV and 5 keV with an angular resolution of 4.5 x 4.5 degrees. The field of view is 4.5 x 76 degrees (nadir-pointing), with the spacecraft motion providing the scanning along the surface.
The STart from a ROtating FIeld mass spectrOmeter (STROFIO) is a neutral particle spectrometer measuring exospheric gas composition. STROFIO consists of ram-facing funnels to collect low-energy particles. The neutral particles are ionized after entering the chamber, and then focused into a beam ions into a dispersing region and into a detector system that measures time-of-flight at various masses, to give a mass/charge ratio. The system can measure particles with energy under 1 eV and a mass range from 1 to 64 AMU at a mass resolution of 60 (M/delta M). The "viewing angle" is 20 degrees, time resolution is 10 seconds.
The Miniature Ion Precipitation Analyser (MIPA) is an ion monitor investigating the chain of processes by which plasma precipitates towards the surface. The ion flux arrival angle is analyzed by an electrostatic deflector and the energy by an electrostatic analyzer. The ions exiting the energy analyzer enter time-of-flight cell consisting of START and STOP surfaces and two continuous channel electron multipliers. MIPA measures particles in an energy range from 15 eV to 15 keV with an energy resolution (delta E/E) of 7%. The field of view is 90 x 300 degrees, using 4 polar and 6 azimuth pixels, giving an angular resolution of 22.5 x 60 degrees. The mass range is 1 to 50 AMU with a resolution (M/delta M) of approximately 5. It requires 18 seconds to cover 96 energy steps over the 24 pixels, giving a sampling time of 7.8 milliseconds.
The Planetary Ion CAMera (PICAM) is an ion mass spectrometer designed to study the ejection from the surface, ionization, and transport of neutral particles in the Mercury environment. PICAM operates as an all-sky camera using aa annular slit in a conical surface allowing a view of an entire hemisphere. Ions enter the slit and pass through a time-of-flight and imaging section. Mass analysis is achieved by a deflection gate, retarding potential analyzer, and detector. It can detect ions with energies up to about 3 keV and masses up to 123 AMU.
SERENA-STROFIO and ELENA are mounted on the upper instrument deck on the Mercury Planetary Orbiter. SERENA-PICAM and SERENA-MIPA are mounted next to each other on the side of the spacecraft near the radiator.
Questions and comments about this experiment can be directed to: Dr. David R. Williams
Name | Role | Original Affiliation | |
---|---|---|---|
Dr. Stefano Orsini | Principal Investigator | Istituto Nazionale di Astrofisica | stefano.orsini@iaps.inaf.it |