## 5 Conclusions  
The paper gives a clear picture of the transformation of the shape and spectrum of UWB EMPs in plasma, magnetized or not, in a wide range of electron densities, for all possible ratios of frequencies of the EMP spectrum, plasma, and electron cyclotron frequencies. On the one hand, the article develops the previously obtained results for isotropic plasma, calculated [4, 5, 17, 21] and experimental [16, 17, 20], for the case of magnetized plasma. On the other hand, it develops previously obtained results on excitation of the response of a dense magnetized plasma [22] for the case of a shorter pulse that excites not only low-frequency whistler waves but also high-frequency electromagnetic waves. The results obtained in this experimental configuration can be used to verify models of EMP propagation in laboratory and ionospheric plasma, including under conditions of nonlinear interaction and resonant absorption of electromagnetic energy. The GCL filled with isotropic or magnetized plasma offers an opportunity to study specific features of pulsed electromagnetic processes having characteristic times, which are shorter than or comparable with the periods of plasma resonance oscillations at the electron plasma frequency \(f_{p}\) and the electron cyclotron frequency \(f_{\rm cr}\). The plasma-filled coaxial line realizes the regime of quasiunidimensional UWB EMP propagation without refraction losses. The direct oscilloscopic detection of pulsed signals makes it possible to describe the characteristics of the EMP in magnetized plasma in terms of the functions of transmission, reflection, and absorption. A UWB EMP is distorted in isotopic plasma due to the effects of the cutoff and frequency dispersion. In dense magnetized plasma (\(f_{p}>>f_{\rm c}\)), the EMP breaks into two wave packets, the high-frequency (\(f>f_{p}\)) and low-frequency (\(f<f_{\rm c}\)) ones. The character of the distortions of the high-frequency packet is similar to the EMP distortions which arise in the case of propagation in isotropic plasma with the same density. The low-frequency packet lies in the range of whistler waves. The EMP distortion regime observed in rarefied magnetized plasma (\(f_{p}<<f_{\rm c}\)) is determined by cyclotron absorption. In this regime, the pulse is followed by a long train of damped oscillations at a frequency close to the cyclotron frequency \(f_{\rm c}\). The objective and the main result of this work are the demonstration of UWB EMP form distortion effects in laboratory magnetized plasma under the conditions of limited simulation of nano- and microsecond EMP propagation in the ionosphere of the Earth. The effects observed should be interpreted quantitatively and qualitatively in future works based on the models developed for the modes of coaxial magnetized plasma waveguides [24] and finite-difference time-domain (FDTD) simulation [21]. Finally, we note that the effects considered in the work can be used to interpret the phenomena that arise during the propagation of UWB EMPs in other media with strong dispersion and resonances, for example, in metamaterials (see [30, 31, 32]). In particular, by filling transmission lines with metamaterials with specially selected properties, controlled transformation of the shape and spectrum of UWB EMPs for basic studies and various applications is possible. Conceptualization, M.G. and I.Z. ; methodology, I.Z., S.K. and A.S.; software, I.Z. ; validation, M.G. ; formal analysis, M.G. and I.Z. ; investigation, I.Z, A.K., V.K. and I.P. ; resources, A.S.; data curation, I.Z. ; writing--original draft preparation, I.Z. and M.G. ; writing--review and editing, M.G. ; visualization, I.Z. ; supervision, M.G. ; project administration, M.G. ; funding acquisition, M.G. All authors have read and agreed to the published version of the manuscript. **Funding:** The study was supported by the Ministry of Science and Higher Education of the Russian Federation, project 075-15-2020-790. **Institutional Review Board Statement:** Not applicable. **Informed Consent Statement:** Not applicable.