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H. Wilczyński

Publications and source records attributed to H. Wilczyński.

4 recordsLinked to original sources

Cosmic ray ensembles as signatures of ultra-high energy photons interacting with the solar magnetic field

Propagation of ultra-high energy photons in the solar magnetosphere gives rise to cascades comprising thousands of photons. We study the cascade development using Monte Carlo simulations and find that the photons in the cascades are spatially extended over millions of kilometers on the plane distant from the Sun by 1 AU. We compare results from simulations which use two models of the solar magnetic field, and show that although signatures of such cascades are different for the models used, for practical detection purpose in the ground-based detectors, they are similar.

astro-ph.HE↗

Feasibility of radar detection of extensive air showers

Reflection of radio waves off the short-lived plasma produced by the high-energy shower particles in the air is simulated, considering various radar setups and shower geometries. We show that the plasma produced by air showers has to be treated always as underdense. Therefore, we use the Thomson cross-section for scattering of radio waves corrected for molecular quenching and we sum coherently contributions of the reflected radio wave over the volume of the plasma disk to obtain the time evolution of the signal arriving at the receiver antenna. The received power and the spectral power density of the radar echo are analyzed. Based on the obtained results, we discuss possible modes of radar detection of extensive air showers. We conclude that the scattered signal is too weak for the radar method to provide an efficient and inexpensive method of air shower detection.

astro-ph.IM↗

Enhancement of the radar signal of air showers due to time compression

We investigate the feasibility of detecting extensive air showers by the radar technique at viewing angles smaller than $\sim 25^\circ$ to the shower axis. Considering a bistatic radar setup and shower geometries in which the receiver points into the arriving shower, we simulate reflection of radio waves off the short-lived plasma produced by the high-energy shower particles in the air. Using the Thomson cross-section for scattering of radio waves and summing coherently contributions of the reflected radio wave over the volume of the plasma disk, we obtain the time evolution of the signal. We analyze the spectral power density of the radar echo and the received power. Based on the obtained results, we discuss possible modes of the radar detection of extensive air showers.

astro-ph.HE↗

Radar reflection off extensive air showers

We investigate the possibility of detecting extensive air showers by the radar technique. Considering a bistatic radar system and different shower geometries, we simulate reflection of radio waves off the static plasma produced by the shower in the air. Using the Thomson cross-section for radio wave reflection, we obtain the time evolution of the signal received by the antennas. The frequency upshift of the radar echo and the power received are studied to verify the feasibility of the radar detection technique.

astro-ph.HE↗