Alina-Mihaela Badescu

Propagation effects on radio signals emitted in salt by neutrino-induced electromagnetic showers

We are investigating the possibility to reconstruct the energy and direction of cosmic neutrinos from the measured voltage of the radio signals emitted. The detector based on the Askaryan effect is built in salt so all propagation effects that affect the characteristics of the generated radio signal should be characterized. Measurements are also influenced by the properties of antenna so its behavior is briefly discussed. We have considered that limitations in resolution of the electronic system is given by ADC and presented its influence on the recovery of direction of the incoming neutrino.

Studies on solar power satellites with down-converter solar cells

ABSTRACT The Solar Power Satellite (SPS) is a renewable energy technology potentially capable of meeting the projected worldwide energy demand for future generations. Some general aspects of SPSs are discussed in this paper. It was calculated that a power output of 97.24 MW (almost double the power produced by a typical natural gas plant) could be generated using a theoretical system with solar photovoltaics with a total optimised dimension of 0.18 km2. Among the potential problems discussed are the possible effect of microwaves on living organisms and the high capital costs involved in building and launching the satellite into a suitable orbit.

Radio-Wave Propagation in Salt Domes: Implications for a UHE Cosmic Neutrino Detector

Salt deposits can be used as a natural dielectric medium for a UHE cosmic neutrino radio detector. Such a detector relies on the capability of reconstructing the initial characteristics of the cosmic neutrino from the measured radio electrical field produced at neutrino’s interaction in salt by the subsequent particle shower. A rigorous characterization of the propagation medium becomes compulsory. It is shown here that the amplitude of the electric field vector is attenuated by almost 90% after 100 m of propagation in a typical salt rock volume. The heterogeneities in salt also determine the minimal uncertainty (estimated at 19%) and the resolution of the detector.

Propagation effects in synchronous underground CDMA systems

This paper investigates the behavior of a CDMA system in conditions of underground propagation collaborated with QPSK modulated signals. The antennas contained in boreholes were modeled as transmission lines. We studied the influence of the impurities of the propagation medium and also presented the role of the dimensions of the drilled cavity that the antennas are contained in. We also investigated the noise introduced by linear quantization. Following the simulation results several conclusions can be drawn in the last chapter.

Consideration on wave propagation in underground dielectrics

We present a study of underground wave propagation in dielectrics. We have determined the influence of the impurities of the propagation medium, of the polarization of waves and the effect that reflections have on the transmitted power. As the antennas as borholed in cavities, we have also presented the influence of the dimensions of the drilled cavity and the role of the medium that fills it.