Solar protons and magnetic storms in February 1962

The satellite Injun 1 (1961o2) detected solar protons during February 2–7, 12, and 20–23, 1962. We will discuss the first of these three periods in detail, with only a brief reference to the following relatively smaller events. Injun 1 was designed and built at the State University of Iowa. It is described in detail by O'Brien and Whelpley [1962]. The satellite was launched on June 29, 1961, and is in an orbit of inclination 66.8°, apogee altitude 998 km, perigee altitude 881 km, and period 104 minutes; the orbit carries the satellite to a geomagnetic latitude of 78°. Injun's fourteen radiation detectors include an APL package of four silicon p–n junction detectors [Pieper, 1961] and a SUI spectrometer background Geiger counter that is sensitive to protons with energy above 40 Mev and forms part of a magnetic electron spectrometer developed by Laughlin [1960] and also described by O'Brien, Van Allen, Laughlin, and Frank [1962]. The APL unit has two orthogonally mounted pairs consisting of detector PNA with its background monitor PNB and PNC with its monitor PND. Detectors PNA and PNC are sensitive to protons in the energy ranges 1.4–17 Mev and 1.6-11 Mev, respectively. As in earlier reports, for brevity we treat the PN energy ranges as 1–15 Mev.