Authors: Savov, E.P., P.I.Nenovski, I.I.Bogomilov, L.I.Simeonov
Reference: Comp.Rend.Acad.bulg.Sci., 43,76, 41-44, 1990
Abstract:
Space projects carried out in the past revealed that plasma
in the Solar System has cellular structure with thin boundary layers
separating plasma regions of widely different characteristics. The data
from the measurements of the charged particle distribution functions and
composition are of fundamental importance for understanding the
occurring plasma processes. These data elucidate the movements and
instabilities of the various magnetospheric boundary layers and the
related coupling mechanisms. Certain magnetopause characteristics are
inferred from the three dimensional particle distributions. The past
history of some plasma populations can be revealed by the character of
the ion distributions. The measurements of the 3D ion distributions and
composition are indispensable for mapping the connections between the
different space plasma regimes and for studying of their interactions.
This work presents a sensor for simultaneous measurement of the 3D ion
and electron distributions. It consists of two collimators and two
geometrically similar nearly quadrispherical electrostatic devices of
?top hat? type with symmetrical optics to ensure uniform velocity space
coverage. The M/Q ratio can be varied by four cross-field velocity
analyzers, occupying four 22.5º sectors. Conditions for free pass of the
ions are secured in adjacent sectors. The ions are accelerated to 20
KeV/Q. The ions and the accelerated electrons are detected on different
chevron microchannel plates and discrete collectors.