An intracloud discharge caused by extensive atmospheric shower

The observational evidence of RB-EAS discharge in a thunderstorm atmosphere is presented. After RB-EAS discharge we name a discharge of a special type developing due to the runaway breakdown (RB) mechanism while an extensive atmosphere shower (EAS) passes through a thundercloud electric field. The observations were fulfilled at the Tien-Shan Mountain Cosmic Ray Station. The widely spread system of oscillation detectors, the special EAS trigger array and the HF radio interferometer were used for measurements.     

Gamma-ray emission from thunderstorm discharges

Fine features of gamma-ray radiation registered during a thunderstorm at Tien-Shan Mountain Cosmic Ray Station are presented. Long duration (100-600 ms) gamma-ray bursts are found. They are for the first time identified with atmospheric discharges (lighting). Gamma-ray emission lasts all the time of the discharge and is extremely non-uniform consisting of numerous flashes. Its peak intensity in the flashes exceeds the gamma-ray background up to two orders of magnitude. Exclusively strong altitude dependence of gamma radiation is found. The observation of gamma radiation at the height 4-8 km could serve as a new important method of atmospheric discharge processes investigation.     

First experience on spatial discrimination of large-scale natural elf interference on the example of two-point measurements of the magnetic field of an artificial ionospheric source

We present the results of an experiment on the generation of extremely low-frequency (ELF) electromagnetic fields at frequencies near the first Schumann resonance upon the ionosphere modification by modulated powerful radio emission. The reception was performed at two sites spaced by 14 km in the distance from “SURA” facility. It was found that the natural noise at different reception sites is highly correlated, which allows one to achieve the noise suppression by about an order of magnitude by subtracting the measurement results. We demonstrate the opportunities of spatial discrimination of the interference upon the two-site reception of the “small-scale” field of an artificial ionospheric source. The directions of future studies and possible applications are discussed. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radio.zika, Vol. 49, No. 12, pp. 1030–1042, December 2006.     

砷化镓光阴极直流高压注入器研究进展

主要介绍自由电子激光相干强太赫兹源（FEL-THz）装置上的砷化镓光阴极直流高压注入器的研究进展,并讨论其驱动未来高重复频率短波长自由电子激光器的差距。通过综合砷化镓阴极寿命的三大影响因素,提出了其工作寿命的定性物理模型;通过该模型对阴极和注入器进行优化,在直流高压电子枪上得到了5 mA, 32 min的连续稳定输出;测量了电子束在4.8 mA下归一化发射度约为4.0 mmmrad,阴极热发射度约为0.6 mmmrad,电子束本征横向能量约为92 meV,250 keV电子束在距离阴极90.6 cm处纵向均方根长度约为11.5 ps。这一束流状态已经基本满足FEL-THz需求。     

Study of interrelation between processes in the thunderstorm atmosphere and energetic cosmic rays with the Groza Tien Shan developmental installation

A Groza installation for studying a lightning discharge mechanism in thunderclouds and clarifying its interrelation with cosmic rays has been designed in the Tien Shan high-altitude cosmic-ray station. The basic results obtained with the Groza installation consisting of detectors serving different purposes and synchronously initiated by a trigger pulse are presented.     

Shape resonances in slow electron scattering by aromatic molecules. I. Anthraquinone derivatives

A series of anthraquinone (C(14)O(2)H(8)) derivatives has been studied by means of electron capture negative ion mass spectrometry (ECNI-MS), photoelectron spectroscopy (PES), and AM1 quantum chemical calculations. Mean lifetimes of molecular negative ions M(-.) (MNI) have been measured. The mechanism of long-lived MNI formation in the epithermal energy region of incident electrons has been investigated. A simple model of a molecule (a spherical potential well with the repulsive centrifugal term) has been applied for the analysis of the energy dependence of cross sections at the first stage of the electron capture process. It has been shown that a temporary resonance of MNI at the energy approximately 0.5 eV corresponds to a shape resonance with lifetime 1-2.10(-13) s in the f-partial wave (l = 3) of the incident electron. The next resonant state of MNI at the energy approximately 1.7 eV has been associated with the electron excited Feshbach resonance (whose parent state is a triplet npi* transition). In all cases the initial electron state of the MNI relaxes into the ground state by means of a radiationless transition, and the final state of the MNI is a nuclear excited resonance with a lifetime measurable on the mass spectrometry timescale. Copyright 1999 John Wiley & Sons, Ltd.     

High-Frequency Radio Emission of the Lightning Discharge

A special system created to register short electromagnetic pulses has been used to study high-frequency (0.1–30 MHz) radio emission of lightning discharges. It has been shown that the emission is a sequence of short pulses. The shape, width, and amplitude of the first (bipolar) pulse agree with those predicted by theory with account for the combined action of the effect of the runaway electron breakdown and an extensive atmospheric shower for the energy of the initial particle of the order of 10¹⁶ eV. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 48, No. 9, pp. 800–809, September 2005.     

The effect of the thunderstorm activity on the tien shan neutron monitor data

Variations in the neutron monitor counting rate at the at the mountain level (3340 m above sea level) during the passage of electrically charged clouds above the installation have been investigated. It is established that the decrease in the counting rate with respect to fair-weather level is due to positive values of the atmospheric electric field (～40–50 kV m^?1). This effect is observed in the low-energy part of the neutron component intensity and is absent in the high-energy part (neutron emission multiplicity exceeds 6).