Rayleigh-Taylor Instability of an Ultrathin Foil Accelerated by the Radiation Pressure of an Intense Laser

Abstract

We report experimental evidence for a Rayleigh-Taylor-like instability driven by radiation pressure of an ultraintense (10(21) W/cm(2)) laser pulse. The instability is witnessed by the highly modulated profile of the accelerated proton beam produced when the laser irradiates a 5 nm diamondlike carbon (90% C, 10% H) target. Clear anticorrelation between bubblelike modulations of the proton beam and transmitted laser profile further demonstrate the role of the radiation pressure in modulating the foil. Measurements of the modulation wavelength, and of the acceleration from Doppler-broadening of back-reflected light, agree quantitatively with particle-in-cell simulations performed for our experimental parameters and which confirm the existence of this instability.

Ion acceleration with radiation pressure in quantum electrodynamic regimes

“…Light sail experiments [33][34][35][36] confirm the expected light sail scaling, but also indicate significant detrimental effects, i.e. the observed ion spectrum is relatively broad, suggesting that transverse inhomogeneity and heating effects need to be reduced.…”

Stable laser-ion acceleration in the light sail regime

“…The interaction is dominated by Rayleigh-Taylor-like instabilities [26]. We investigated the balance condition further by performing the experiment with laser pulse duration of 70 fs, i.e.…”

Enhancement of proton energy by polarization switch in laser acceleration of multi-ion foils

“…17 This is a more efficient acceleration process for producing high energy monoenergetic protons, suitable for many applications requiring that the accelerated protons have good beam quality and a narrow energy spectrum. However, previous works demonstrated with two-dimensional (2D) particle-in-cell (PIC) simulations 16,18,[22][23][24] that the Rayleigh-Taylor instability (RTI) limits the acceleration achieved by RPA and rapidly broadens the proton beam's energy spectrum. For RPA of thin-foil targets of one species, the energy scaling study with PIC simulation 18 indicates that petawatt power laser is needed to obtain $200 MeV quasi-monoenergetic protons with energy spread within 20% of the peak flux energy, which may make the laser proton acceleration scheme less attractive for commercial practical applications, as it is difficult to build a petawatt laser, and the laser also produces strong radiation that is difficult to shield.…”