Instrument Information
IDENTIFIER urn:nasa:pds:context:instrument:pvo.opa::1.2
NAME Solar Wind Plasma Analyzer (OPA) for Pioneer Venus
TYPE Charged Particle Detector
DESCRIPTION The Solar Wind Plasma Analyzer (OPA) is a quadrispherical electrostatic analyzer designed to measure solar wind conditions such as velocity, density, flow direction, and temperature in various locations around Venus. It weighs 3.9 kg and operates on 5 W of power. The instrument features a pair of spherical plates with an entrance aperture that allows charged particles to pass through, eventually striking one of five current collectors. It can vary the voltage between the plates from 50 V to 8000 V for ions and from 3 V to 250 V for electrons, covering an extensive energy/charge range. It has a detection capability of particle flux in a 360-degree azimuth range and +/-85 degrees in elevation. The OPA operates in two modes: a command able scan mode to identify peak particle fluxes and a step mode for specific flux measurements.
MODEL IDENTIFIER
NAIF INSTRUMENT IDENTIFIER
SERIAL NUMBER not applicable
REFERENCES Intriligator, D. S., et al., The Pioneer Venus Orbiter plasma analyzer experiment, IEEE Trans. Geosci. Rem. Sens., GE-18, No. 1, 39-43, Jan. 1980.

Wolfe, J., et al., Initial observations of the Pioneer Venus Orbiter solar wind plasma experiment, Science, 203, No. 4382, 750-752, Feb. 1979.

Intriligator, D. S., et al., Electron observations and ion flows from the Pioneer Venus Orbiter plasma analyzer experiment, Science, 205, No. 4401, 116-119, July 1979.