Heavy Ion Cosmic Rays Observed by the ONR-604 Instrument on the CRRES Satellite

Session 33 -- Gamma-Rays and Cosmic Rays
Display presentation, Tuesday, 9:30-6:30, Heller Lounge Room

[33.13] Heavy Ion Cosmic Rays Observed by the ONR-604 Instrument on the CRRES Satellite

Y.Sang, J.Chen, T.G.Guzik, J.P.Wefel (LSU), K.R.Pyle (U. of Chicago)

The heavy ion cosmic ray environment was measured by the University of Chicago ONR-604 instrument on the CRRES mission from September 1990 to October 1991. CRRES was in a highly elliptical orbit and traveled through the magnetosphere from a perigee of 350 km to an apogee of 33,580 km, with an inclination of 18.2 degrees. ONR-604, a solid state detector telescope, observed heavy ions at 50 to 500 MeV/nucleon. Here we report the first observation of the geomagnetically trapped high energy helium ions (120 to 400 MeV) at magnetic $L < 2.3$. Their energy spectrum, pitch angle and space distributions are presented. We also discuss measurements of the solar energetic particles from the major flares that occured during the CRRES mission. In particular, a burst of heavy ions was observed which were apparantly associated with the June 15, 1991 flare.

This work is supported in part by NASA contracts NAGW 2368, NAG 5-706, by U.S. Air Force contracts F19628-90-K-0025, -0026, and by ONR grant N00014-90-J-1466.

Tuesday program listing