NSSDCA ID: 1964-076B-03
Mission Name: Injun 4This experiment was designed to measure the net down-flux of particles from the trapping region and the intensities of geomagnetically trapped particles at low altitudes, over a wide range of latitudes and longitudes and a long period of time, and to study the long-term decay of electrons in the artificially produced "Starfish" radiation belt. Four Eon 6213 type directional GM counters were used for energy flux measurements. These counters were sensitive to electrons (E>40 keV) and protons (E>600 keV). The detectors were arranged to detect particles with pitch angles from 0 to 180 deg in four segments centered at pitch angles of 35, 90, 125, and 160 deg. Orientation was referred to the direction of the local magnetic field line such that 0 deg corresponded to a detector looking downward towards the earth in the northern hemisphere. The 6213 GM counters at 35 and 160 deg functioned normally throughout the flight, while the counter at 90 deg operated properly only until about mid-March 1965. Periods of intermittent operation commenced at that time due to continuous discharge of the GM counter, and the counter failed completely in June 1965. The fourth counter, at 125 deg, malfunctioned shortly after launch and yielded no useful data. One heavily shielded omnidirectional Eon 6213 type counter was used for the study of the Starfish radiation. This counter was sensitive to protons (E>70 MeV) but insensitive to electrons except via bremsstrahlung (E>1 MeV). One omnidirectional 5112 type GM counter of the kind flown on the Explorer 7 satellite and one omnidirectional 7302 type GM counter were used for monitoring the natural radiation zones and cosmic rays. The 5112 GM counter was sensitive to protons (E>27 MeV) but insensitive to electrons except via bremsstrahlung (E>1 MeV). The four directional type 6213 GM counter accumulators were sampled sequentially every 4 s, and the other GM counter accumulators were sampled sequentially every 8 s.
Bit rate (avg): 0.144 kbps
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Name | Role | Original Affiliation | |
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Prof. James A. Van Allen | Principal Investigator | University of Iowa |