Gigantic Coaxial Line for Experimental Studies of the Interaction of Nanosecond Electromagnetic Pulses with an Ionized Gas Medium

Abstract

A large-scale coaxial line filled with the plasma of RF discharge has been developed for laboratory modeling of the effects of the interaction of ultrashort electromagnetic pulses (EMPs) with the atmosphere and the ionosphere in the KROT facility. The oversized coaxial line ensures pulse transmission through an ionized medium in the TEM mode, which corresponds to the polarization of the transverse electromagnetic wave in free space, and in uniform isotropic plasma. The coaxial line has a length of 10 m and a diameter of 140 cm. The processes of propagation of the nanosecond and subnanosecond pulses in this line, in vacuum and with plasma, have been simulated numerically.

Microwave Cavity Sensor for Measurements of Air Humidity under Reduced Pressure

“…Under controlled external pressure and temperature conditions, the sensor can be used conveniently as a routine humidity control instrument in the laboratory modeling of electric discharge phenomena in the Earth’s atmosphere, including air ionization in the field of the electromagnetic pulse [ 38 ] and streamer discharges [ 39 ]. In geophysical sensor applications, one should allow for the influence of temperature on the device readings due to the changes in the geometric dimensions of the cavity.…”

Transformation of the Shape and Spectrum of an Ultrawideband Electromagnetic Pulse in a “Gigantic” Coaxial Line Filled with Magnetized Plasma

“…This diagram allows one to evaluate the balance of the EMP energy transmitted through, reflected from, and absorbed in the GCL filled with magnetized plasma. Note that the amplitude-frequency characteristics of the signal reflected from the GCL are uneven due to details of its design [19,20]. This diagram shows that, first, the EMP energy is dissipated in plasma at the frequencies close to f c and 2f c , i.e., resonance absorption takes place in rarified plasma.…”

“…The experiments were performed using the gigantic coaxial line (GCL) [19,20] installed inside the chamber of the large-scale Krot plasma device (Figure 1). This device is used for simulating space plasma and is described in detail in [18].…”

“…Recently, a new scientific instrument (a "gigantic" plasma-filled coaxial line, GCL) has been added to this device. The GCL was described in full detail in [19] and allows one to study the interaction of EMPs with durations from 300 ps with gases and plasmas including magnetized ones. Today, this is the only instrument of its kind that makes it possible to experimentally study linear and nonlinear effects in plasma during the passage of a UWB EMP along a path with a total length of about 10 m. The preliminary experimental results obtained by using the GCL were published in [20].…”