Enhancement of vacuum polarization effects in a plasma

Abstract

The dispersive effects of vacuum polarization on the propagation of a strong circularly polarized electromagnetic wave through a cold collisional plasma are studied analytically. It is found that, due to the singular dielectric features of the plasma, the vacuum effects on the wave propagation in a plasma are qualitatively different and much larger than those in pure vacuum in the regime when the frequency of the propagating wave approaches the plasma frequency. A possible experimental setup to detect these effects in plasma is described.Comment: 33 pages, 3 figure

Extremely high-intensity laser interactions with fundamental quantum systems

“…It was first realized in Di Piazza et al, 2007b that this aspect can be in principle significantly improved in a plasma. For the sake of simplicity the case of a cold plasma was considered and the vacuum-polarization effects were implemented in the inhomogeneous Maxwell's equations as an additional "vacuum four-current" (Di Piazza et al, 2007b). Now, unlike in the vacuum, the field invariant F (x) for a single monochromatic circularly polarized plane wave does not vanish in a plasma.…”

“…This region of parameters is in general complex to investigate, due to the arising of different instabilities. However, the idealized situation investigated in Di Piazza et al, 2007b shows, at least in principle, the possibility of enhancing the vacuum-polarization effects by an order of magnitude at a given intensity …”

Quantum interaction among intense laser beams in vacuum

“…By exploiting the peculiar behaviour of the plasma in the presence of a wave with a frequency near the plasma frequency, i.e. at n 0,pl 1, an enhancement of vacuum polarization effects of more than one order of magnitude has been predicted theoretically in [35]. In the same paper other aspects of the problem are addressed, like the presence of collisions between electrons and ions which can be determinant in the regime of laser frequencies slightly above the plasma frequency.…”

“…Since the wave intensity is supposed to be about 10 22 -10 23 W/cm 2 , the plasma is highly relativistic and completely ionized. If we assume for simplicity that the plasma is homogeneous and that a two-fluid (electron and ion fluids) description of the plasma can be used (cold plasma approximation), it is then possible to show that, by accounting for vacuum polarization, in the presence of a circularly polarized plane wave the plasma refractive index is determined by the formula [35] n 0 = n 2 0,pl + 2α 45π…”

Numerical investigation and potential tunability scheme on and stimulated pair creation from vacuum using high intensity laser beams

“…The rapid development of ultra-intense laser facilities has rekindled the interest in proposing a possible experimental Correspondence to: I. Ploumistakis, Technical University of Crete, Laboratory of Matter Structure and Laser Physics, Chania 73100, Greece. Email: iploumistakis@isc.tuc.gr setup as seen in various works [3][4][5][6][7][8][9][10][11] . Theoretical treatment of pair creation in an oscillating pure electric field and based on the atom ionization theory, was demonstrated in Brezin and Itzykson [12] and Popov's works [13][14][15][16][17][18][19] .…”