The Ion Mass Analyzer (IMA) of the ASPERA-4 package
flown on Venus Express provides ion measurements in the energy range 
0.01 - 36 keV/q for the main ion components H+, H2+, He+, O+, and for the 
group of molecular ions with M/q ration between 20 and 80 amu/e. IMA has a 90 deg x 360 deg field 
of view. Electrostatic sweeping performs elevation (+/- 45 deg) coverage. 
The IMA sensor is a spherical electrostatic analyzer followed by a circular 
magnetic separating section. A large diameter MCP with a discrete anode images 
the matrix azimuth x mass.

Reference: 
Barabash et al.,  The Analyser of Space Plasmas and Energetic Atoms (ASPERA-4) for the Venus Express mission,
Planetary and Space Science,
Volume 55, Issue 12, 2007, Pages 1772-1792, ISSN 0032-0633,
https://doi.org/10.1016/j.pss.2007.01.014.