Upper limit for the solar neutron flux in the energy interval 20–120 MeV

✍ Scribed by D. J. Forrest; E. L. Chupp

• Book ID: 104641102
• Publisher: Springer
• Year: 1969
• Tongue: English
• Weight: 644 KB
• Volume: 6
• Category: Article
• ISSN: 0038-0938
• DOI: 10.1007/bf00146469

✦ Synopsis

An experiment has been performed to search for the existence of a flux of solar neutrons at the earth using a detector sensitive to neutrons in the energy region 20--120 MeV. The instrument was carried by balloon to an atmospheric depth of ~ 4 g/cm ~', from Palestine, Texas on the morning of November 2, 1967 and flown through sunrise and for about 7 hours into the day. Numerous flares of importance IB or less occurred during the float period. By comparison of night and day counting rates we have deduced that the upper limit to the continuous emission of solar neutrons at the earth is ~ 2 • 10 -~ neutrons/cm 2 sec in the above energy region. Using a theoretical form for the neutron differential energy spectrum we have expressed this result as an upper limit differential solar neutron flux. If neutrons were emitted in association with any of the small flares then the maximum flux at the earth was less than ~ 4 • 10 z neutron/cm z sec in the same energy region. The minimum detectable flux with the present instrument is therefore well below the predicted flux from a 3B flare (e.g., Nov. 12, 1960) of 5-+," 50 neutrons/cln'-' scc.