アイテム詳細

要旨

In this work we are investigating non-linear electromagnetic waves in two different physical environments: laboratories on earth and the astrophysical objects known as pulsars. In the first part of our work the interaction of electrons and positrons with strong waves in the form of high intensity laser beams is analyzed. The possibility of emission of energetic radiation which can result in prolific pair production in the focus of two short, counter-propagating ultrahigh intensity laser pulses is examined, taking into account several different possibilities for the relative polarizations and the waveform of the beams. The conclusion is reached that in the next generation laser facilities currently under construction mainly in Europe, like ELI and the 10PW Vulcan laser, pair production and electromagnetic pair cascades should be observed for intensities as low as 10²⁴Wcm⁻². In the second part of this work we focus on large amplitude, low frequency waves that are emitted by pulsars. After a brief review of the current understanding of pulsar winds and the problems inherent to it, we show that the interaction of a relativistic striped pulsar wind with the the termination shock should result in reflection of electromagnetic energy in the upstream, which can affect the outflow, creating a precursor. We then investigate the possible conversion of the pulsar wind to a superluminal linearly polarized wave propagating upstream of the termination shock and show that this will result in the transfer of energy from the fields to the outflow particles in the precursor, lowering the magnetization of the outflow and opening the way for further particle acceleration at the shock front.