scholarly journals Asymmetric Backward Peaking Radiation Pattern from a Relativistic Particle Accelerated by Lightning Leader Tip Electric Field

2021 ◽  
Author(s):  
Mert Yücemöz ◽  
Martin Füllekrug
Keyword(s):  
Electric Field ◽  
Radiation Pattern ◽  
Relativistic Particle ◽  
Lightning Leader

Backward peaking radiation pattern from a relativistic particle accelerated by lightning leader tip electric field

2020 ◽  
Author(s):  
Mert Yucemoz
Keyword(s):  
Electric Field ◽  
Radiation Pattern ◽  
Gamma Rays ◽  
Relativistic Particle ◽  
Radio Waves ◽  
Radiation Patterns ◽  
Lightning Leader ◽  
Bremsstrahlung Process ◽  
Relativistic Particles ◽  
Frequency Approximation

<div> <p>Charged particles being accelerated by the lightning leader tip electric field emit electromagnetic radiation due to the Bremsstrahlung process (Celestin et al., JGR, 2012). Bremsstrahlung has a continuous spectrum of radiation which includes radio waves and ionising radiation such as gamma rays which can be recorded by detectors on board the ASIM payload on the International Space Station, the forthcoming TARANIS satellite, or on the ground (Abbasi et al., JGR, 2018).  </p> </div><div> <p>The radiation pattern of this Bremsstrahlung is not well known. Displays of radiation patterns of accelerated particles are normally limited either to a low frequency approximation for radio waves, or to linear acceleration in a high frequency approximation for gamma rays. Here we report the radiation patterns from accelerated relativistic particles at low and high frequencies of the Bremsstrahlung process. It is found that the radiation patterns have four relative maxima with two backward peaking and two forward peaking.  </p> </div><div> <p>The shape of the radiation pattern is only determined by the velocity of the particle whilst the intensity of the radiation pattern is determined by the velocity and the acceleration of the particle. For example, relativistic particles with a large velocity exhibit a radiation pattern which is more forward peaking when compared to a non-relativistic particle with a smaller velocity. Similarly, relativistic particles with a large acceleration exhibit a radiation pattern with a larger intensity when compared to relativistic particles with a smaller acceleration. All these radiation patterns exhibit backward peaking radiation. The asymmetry of the radiation pattern, I.e., the different intensities of forward and backward peaking lobes, is controlled by the asymmetric frequencies of the Bremsstrahlung radiation caused by the Doppler effect.  </p> </div><div> <p>These results are important because they enable a determination of particle properties which can be inferred from observations with networks of radio receivers and arrays of gamma ray detectors. </p> </div>

scholarly journals Radiation Pattern Reconfigurable Waveguide Slot Array Antenna Using Liquid Crystal

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Hongyu Shi ◽  
Jianxing Li ◽  
Shitao Zhu ◽  
Anxue Zhang ◽  
Zhuo Xu
Keyword(s):  
Dielectric Constant ◽  
Liquid Crystal ◽  
Electric Field ◽  
Radiation Pattern ◽  
Array Antenna ◽  
Antenna Element ◽  
Waveguide Slot ◽  
Radiation Direction ◽  
Coupled Resonator

In this paper, we proposed a radiation pattern reconfigurable waveguide slot array antenna using liquid crystal (LC). Together with the waveguide slot, the designed complementary electric-field-coupled resonator functions like a switch controlled by the dielectric constant of the LC, which can control the antenna element to radiate or not. Thus, the array factor and radiation pattern can be manipulated. The proposed antenna was simulated, fabricated, and measured. Its radiation direction can be reconfigured to 46° or 0° at about 15 GHz.

scholarly journals A model for electric field enhancement in lightning leader tips to levels allowing X‐ray and γ ray emissions

2015 ◽  
Vol 120 (6) ◽  
pp. 5087-5100 ◽  
Author(s):  
L. P. Babich ◽  
E. I. Bochkov ◽  
I. M. Kutsyk ◽  
T. Neubert ◽  
O. Chanrion
Keyword(s):  
Electric Field ◽  
Field Enhancement ◽  
Electric Field Enhancement ◽  
X Ray ◽  
Lightning Leader ◽  
Γ Ray

scholarly journals Constraints to do realistic modeling of the electric field ahead of the tip of a lightning leader

2017 ◽  
Vol 122 (15) ◽  
pp. 8120-8134 ◽  
Author(s):  
Alexander Broberg Skeltved ◽  
Nikolai Østgaard ◽  
Andrew Mezentsev ◽  
Nikolai Lehtinen ◽  
Brant Carlson
Keyword(s):  
Electric Field ◽  
Realistic Modeling ◽  
Lightning Leader
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