A Caltech Library Service

A Search for Solar Flare Positrons

Mewaldt, R. A. and Stone, E. C. and Vogt, R. E. (1975) A Search for Solar Flare Positrons. In: Proceedings of the 14th International Cosmic Rays Conference. Vol.5. Max Planck Gesellschaft , pp. 1668-1673.

PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


The detection of solar γ-ray line emission and observations of the isotopes ^2H, ^3H and ^3He in solar cosmic rays provide direct evidence for the occurrence of high energy nuclear reactions in solar flare events. Appreciable numbers of other reaction products, including positrons with energies near ~ 1 MeV, should also be produced in such events. We have searched for positrons in the 0.16-1.6 MeV energy interval during 5 "^3He rich" solar particle events observed by the Caltech Electron/Isotope Spectrometers on IMP 7 and 8. Based on calculations of positron and ^3He production at the sun, and using a simplified model of interplanetary propagation, we might expect comparable fluences of positrons and ^3He to be observed. Summing over these 5 events, however, we find the 0.16 to 1.6 MeV positron fluence to be < 10% of the > 1 MeV/nuc ^3He fluence. This suggests that other processes, such as preferential trapping by the solar magnetic field, may be important.

Item Type:Book Section
Related URLs:
URLURL TypeDescription
Mewaldt, R. A.0000-0003-2178-9111
Stone, E. C.0000-0002-2010-5462
Contact Email
Additional Information:© 1975 MPE. Provided by the NASA Astrophysics Data System. This work was supported in part by the National Aeronautics and Space Administration under Contract NAS5-11066 and Grant NGR 05-002-160.
Group:Space Radiation Laboratory
Funding AgencyGrant Number
NASANGR 05-002-160
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Space Radiation Laboratory1975-02
Record Number:CaltechAUTHORS:20140409-104148866
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:44820
Deposited By: SWORD User
Deposited On:14 Apr 2014 23:05
Last Modified:20 Feb 2020 14:33

Repository Staff Only: item control page