THE SUDDEN INCREASE IN COSMIC RAY INTENSITY, NOVEMBER 19, 1949

• Published in: Canadian Journal of Physics
• Main Author: Rose, D. C.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1951
• Subjects: General Physics and Astronomy; Arctic
• Online Access: http://dx.doi.org/10.1139/p51-027; http://www.nrcresearchpress.com/doi/pdf/10.1139/p51-027

Cosmic ray counter telescopes were in continuous operation on November 19, 1949, at Ottawa (geomagnetic lat. 56.8°N) and at Resolute (geomagnetic lat. 83°N) in the Canadian Arctic. The two sets of apparatus were identical and consisted mainly of two counter telescopes, one with six inches and the other with 14½ inches of lead between counters. At Ottawa the counting rates of the individual counter trays were recorded as well as that of the coincidences.On November 19 at about 1048 GMT a sudden increase occurred at Ottawa. The maximum intensity reached about 70% above normal in a few minutes, then decayed slowly to normal in about four hours. The increase was similar in both counter telescopes and in the individual counter trays. At Resolute an increase was noted but of a different type. The intensity did not rise suddenly but increased slowly to about 20% above normal and returned to normal again in about three hours, centered about 1140 GMT. These results and those of other observers indicate that the beam of rays responsible for this increase must strike the earth on a limited area only. Some deductions can be made about the extent of this area.