Instrument Overview
  ===================
    The plasma analyzer instrument carried by the Pioneer 10 spacecraft
    looked toward the Sun through a hole in the spacecraft's large
    dish-shaped antenna. The solar wind entered the plasma analyzer
    apertures between 2 quadraspherical plates where the direction of
    arrival, the energy, and the number of ions and electrons making up
    the solar wind were measured.
 
    The instrument had a high resolution and a medium resolution
    analyzer to detect particles of different energy levels. Energies of
    these particles were described in terms of electron volts (eV).
 
    A voltage was applied across the quadraspherical plates in a maximum
    of 64 steps, at a rate of one step per spacecraft revolution, to
    count particles in discrete energy ranges. Direction of particle
    travel was found from the way the instrument was pointed and from
    the particular target within the instrument that detected it.
 
    The high resolution analyzer had 26 continuous-channel multipliers
    (CCM) to measure the number of ions per second between 100 and 8,000
    electron volts. The medium resolution analyzer had five
    electrometers to count ions of 100 to 18,000 electron volts and
    electrons of 1 to 500 electron volts.
 
  ['Instrument Overview' was adapted from FIMMELETAL p. 50-51.]