Geiger-Muller Counter Measurements of the Eclipse

Abstract

The annular eclipse occurred in the southeast of Japan for 5 min on May 21 2012 7:32, we measured the change in ambient dose rate by using Geiger-Muller counters at three locations, which were Nagareyama, Hino, and Setagaya in Tokyo district.We calculate the frequency spectrum of the observations, and find the spectrum has two distributions. Time scale of the higher-frequency is 2∼2.6 min. We execute an inverse Fourier transformation for the higher-frequency part, and reproduce the change of ambient dose rate. It suggests a phenomenon like scintillation in secondary cosmic ray. It subsides after a delay of more than 5∼22 min from the time of maximum eclipse servings, and then, it scintillates again. We believe the scintillation relates with the solar wind because of the delay time.