V. V. Alexeenko

Transient variations of secondary cosmic rays due to atmospheric electric field and evidence for pre-lightning particle acceleration

We present the data on short-term variations of the intensity of secondary cosmic rays during thunderstorm periods. The effect is studied separately for the soft (electrons) and hard (muons) components of cosmic rays, their intensities being correlated with the near-earth electric field using a second-order polynomial. It is shown that the linear and quadratic terms are dominant for the soft and hard components, respectively. In addition, some irregular enhancements of the soft component just before lightning discharges are observed giving evidence in favor of some particle acceleration process. They can be considered as an experimental confirmation of the runaway breakdown theory developed for the process of lightning initiation.

Baksan EAS experiment on UHE gamma ray astronomy

Baksan EAS array was among the first to make a start of the purposeful UHE gamma‐ray astronomy observations. A lot of experimental data has been recorded up to now and some positive indications on the signals from several possible sources was found. The data on steady flux from three possible sources are presented. Several burst‐like events were recorded during the observation period, and in this paper the Crab Nebula event on February 23, 1989, the only one having the confirmation from other groups, is being analysed.