[3][4] Explorer 47 continued the study begun by earlier IMP spacecraft of the interplanetary space and magnetotail regions from a nearly circular orbit, near 37 Earth radii.
[5] This experiment was designed to measure solar and galactic electrons, positrons, and nuclei, and to separate isotopes from hydrogen through oxygen.
The instrument was a telescope consisting of 11 colinear, fully depleted, silicon surface-barrier detectors inside a plastic scintillator anticoincidence shield.
Data returned consisted of 8-sectored and spin-integrated count rates for 8 different coincidence/anticoincidence modes and 2 parameter pulse-height analyses for 32 particles every 20.48-seconds.
The instrumentation consisted of a three-element telescope employing fully depleted surface-barrier solid-state detectors and a magnet to deflect electrons.
[7] This experiment was designed to determine the composition and energy spectra of low-energy particles associated with solar activity and interplanetary processes.
The telescope failed on 25 November 1972, when the window on the proportional counter weakened and burst due to exposure to UV radiation.
[8] This experiment consisted of a boom-mounted triaxial fluxgate magnetometer designed to study the interplanetary and geomagnetic tail magnetic fields.
[9] This experiment measured the energy spectra of low-energy electrons and protons in the geocentric range 30 to 40 Earth radii to further understand geomagnetic storms, aurora, tail and neutral sheet, and other magnetospheric phenomena.
The frequency channels were incremented, and the sampled sensors were alternated until a full set of data was obtained in 16 measurement periods (approximately 20-seconds).
[11] The Goddard Space Flight Center cosmic-ray experiment measured energy spectra, composition, and angular distribution of solar and galactic electrons, protons, and heavier nuclei up to Z=30.
The first system consisted of a pair of solid-state telescopes that measured integral particle fluxes above 150, 350, and 700 keV and of protons above 0.05, 0.15, 0.70, 1.0, 1.2, 2.0, 2.5, 5.0, 15, and 25 MeV.
The main telescope consisted of five colinear elements (three solid state, one CsI, and one Cherenkov sapphire) surrounded by a plastic anticoincidence shield.
[13] A hemispherical electrostatic analyzer was used to study the directional intensity of positive ions and electrons in the solar wind, magnetosheath, and magnetotail.
Energy analysis was accomplished by charging the plates to known voltage levels and allowing them to discharge with known RC time constants.
[14] A modulated split-collector Faraday cup, which was perpendicular to the spacecraft spin axis, was used to study the directional intensity of positive ions and electrons in the solar wind, transition region, and magnetotail.
[15] An electrostatic analyzer and Wien-type velocity selector were used to gain exploratory data on heavy ion composition in the solar wind.
During 30 successive spacecraft spin periods, ions of a given species were studied in 30 logarithmically equispaced bulk velocity channels from 200 to 600 km/s (120 to 370 mi/s).
A collimated stilbene crystal scintillator looking perpendicular to the spacecraft spin axis served as the principal detector.
A fully shielded CsI crystal served as a gamma-ray spectrometer and was used in coincidence with the principal detector to distinguish electrons from positrons.
In addition, the amplitude and shape of the pulse generated in the principal detector by the first stopping particle in each appropriate telemetry frame was studied.