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Register a new userThe prolonged gamma ray enhancement and the short radiation burst events observed in thunderstorms at Tien Shan
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A. Shepetov
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We report the observation results of the hard radiation flashes which accompanied the lightning discharges above the mountains of Northern Tien Shan. Time series of the counting rate intensity, numerical estimations of absolute flux, and energy distribution of accelerated electrons and of (20-2000)keV gamma rays were obtained at the height of 3700m a.s.l., immediately within thunderclouds, and in closest vicinity ($<$100m) to discharge region. Two different kinds of radiation emission events are presented here: a relatively prolonged rise of gamma ray intensity with minute-scale duration (the thunderstorm ground enhancement, TGE) which has preceded a negative field variation, and a short sub-millisecond radiation burst, which accompanied a close lightning discharge in thundercloud. It was revealed also an indication to positron generation in thunderclouds at the time of gamma ray emission, as well as modulation of the neutron counting rate in Tien~Shan neutron monitor which was operating at a (1.5-2)km order distance from the region of lightning development.
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A search for the possible precursors of an earthquake and its effect on the data series of diverse geophysical parameters has been made in the mountain of Northern Tien Shan. The complex installation included the NM64 type neutron supermonitor, detectors of the environmental low-energy neutrons, the scintillation gamma-detector, the sensor of the local electric field, a seismograph, and a weather-station. The specialized data filtration methodic was elaborated with an enhanced sensitivity to the transient signals of seismic origin. On the eve of, and after a 5.4 magnitude earthquake the fine features in temporal behavior of the intensity of low-energy neutron and gamma-radiation background, so as irregularities of the local electric field were observed which seem to be in a close correlation with each other. These results may be an evidence of the possibility of experimental identification of earthquakes precursors in the time up to 2-3 days before the beginning of a period of intensive tectonic activity.
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