Some preliminary results of the Pioneer V magnetometer experiment

The purpose of this note is to make a preliminary report of findings provided by the magnetometer carried aboard the Pioneer V space probe. Data have been examined for the first 50 days of operation. These data are still being processed, and the analysis is incomplete. The magnetometer used for this experiment was similar to the search coil carried on Pioneer I [Sonett, Judge, Kelso, and Sims, 1960] and Explorer VI [Sonett, Smith, and Sims, 1960]. The instrument is a two-axis magnetometer measuring the amplitude of the component of the magnetic field that is normal to the spin axis of the vehicle. This component will hence-forth be designated as |B⊥|. Electronic modifications have been made to the amplifier so as to decrease the threshold, which is now 1 microgauss. In addition, the telemetry of Pioneer V is completely digitized.