P3: An installation for high-energy density plasma physics and ultra-high intensity laser–matter interaction at ELI-Beamlines

Abstract

ELI-Beamlines (ELI-BL), one of the three pillars of the Extreme Light Infrastructure endeavour, will be in a unique position to perform research in high-energy-density-physics (HEDP), plasma physics and ultra-high intensity (UHI) (1022W/cm2) laser–plasma interaction. Recently the need for HED laboratory physics was identified and the P3 (plasma physics platform) installation under construction in ELI-BL will be an answer. The ELI-BL 10 PW laser makes possible fundamental research topics from high-field physics to new extreme states of matter such as radiation-dominated ones, high-pressure quantum ones, warm dense matter (WDM) and ultra-relativistic plasmas. HEDP is of fundamental importance for research in the field of laboratory astrophysics and inertial confinement fusion (ICF). Reaching such extreme states of matter now and in the future will depend on the use of plasma optics for amplifying and focusing laser pulses. This article will present the relevant technological infrastructure being built in ELI-BL for HEDP and UHI, and gives a brief overview of some research under way in the field of UHI, laboratory astrophysics, ICF, WDM, and plasma optics.

Reaching supercritical field strengths with intense lasers

“…Experiments at a 0 ;0.4, χ e ;0.3 have demonstrated nonlinear QED effects including pair creation [6,7], and recently evidence of radiation reaction has been reported at a 0 ;10, χ e ;0.1 [27,28]. At present, the highest field strengths are equivalent to a 0 ;50 [29,30], or χ 0 ;1 at γ 0 m;1 GeV; a 0 >100 is expected in the next generation of laser facilities [31][32][33]. The stronger the electromagnetic field, the lower the electron energy that is needed to reach high χ e .…”

“…However, unless the pulse duration is as little as a few cycles in length (when radiation 'quenching' is possible [44]), radiation reaction strongly reduces the number of electrons that get close to the maximum possible χ e . This can be mitigated by moving to collisions at oblique incidence, because the spot to which a laser pulse is focussed (∼2 μm) is typically smaller than the length of its temporal profile (20 fs [31], 30 fs [29,30,33] or 150 fs [32]). Even though the maximum possible χ e at θ>0 is smaller than that at θ=0, many more electrons get close to the maximum because the interaction length is shorter and radiative losses are reduced.…”

Identifying the electron–positron cascade regimes in high-intensity laser-matter interactions

“…Illustrated are the cascading regimes 1-exponential growth, 2-saturation and 3-cascade suppressed, identified in section 2.4. 2 This can be above the critical density even before saturation has occurred (see the density spikes in figure 2), potentially leading to the spurious identification of a critical density pair plasma in figure 3. However, this is only a problem late in the exponential growth phase, which is reached after 40fs for a narrow range of initial densities and laser intensities.…”

“…An electromagnetic cascade can ensue if many generations of electrons and positrons can be generated by the fields. Usually this occurs via a two-step process whereby the electrons and positrons produced by the Breit-Wheeler process radiate photons by nonlinear Compton scattering which subsequently decay to further pairs and so on.Upcoming facilities, like several of those comprising the extreme light infrastructure (ELI) [1,2], are expected to reach laser intensities of > -…”

Characterizing extreme laser intensities by ponderomotive acceleration of protons from rarified gas

“…Over the past two decades, significant progress in short-pulse high-power laser technology has resulted in the development of petawatt-class lasers [1][2][3][4][5][6][7][8][9][10][11][12], ten petawatt-class lasers [13][14][15][16][17][18]. Even higher power laser systems have been proposed [19].…”