WIND measurements of protonand alpha particle flow and number density

J. T. Steinberg, A. J. Lazarus, K. W. Ogilvie, R. Lepping, J. Byrnes, D. J. Chornay, J. Keller, R. B. Torbert, D. Bodet, and G. J. Needell

Center for Space Research, Massachusetts Institute of Technology, Cambridge, MA


The material summarized here is to be submitted to Geophysical Research Letters.

The WIND satellite, launched November 1, 1994, carries an array of instruments for investigating the interplanetary medium. The solar wind experiment (SWE) on WIND includes 2 Faraday cup detectors for measuring the energy/charge spectrum of solar wind protons and alpha particles. The Faraday cups provide good measurements of the ion bulk density, and thermal speed, and are particularly well suited for accurately determining the bulk velocity flow vector. Under most conditions, the density, thermal speed and velocity are obtained separately for protons and alpha particles, and the proton-alpha particle differential flow can be determined. We present early SWE Faraday cup results and compare proton and alpha particle properties.

Proceedings of Solar Wind Eight, p. 203, 1996