Radiation-Pressure Acceleration of Ion Beams from Nanofoil Targets: The Leaky Light-Sail Regime

Proton acceleration by ultra-intense laser pulse irradiating a target with cross-section smaller than the laser spot size and connected to a parabolic density channel is investigated. The target splits the laser into two parallel propagating parts, which snowplow the back-side plasma electrons along their paths, creating two adjacent parallel wakes and an intense return current in the gap between them. The radiation-pressure pre-accelerated target protons trapped in the wake fields now undergo acceleration as well as collimation by the quasistatic wake electrostatic and magnetic fields. Particle-in-cell simulations show that stable long-distance acceleration can be realized, and a 30 fs monoenergetic ion beam of >10 GeV peak energy and <2 divergence can be produced by a circularly polarized laser pulse at an intensity of about 10 22 W/cm 2 . V C 2013 American Institute of Physics. [http://dx

Section: Introductionmentioning

confidence: 99%

Laser-driven collimated tens-GeV monoenergetic protons from mass-limited target plus preformed channel

Zheng

et al. 2013

“…[1][2][3][4][5][6][7][8][9] Considerable effort has been put into both the theoretical and, more recently, the experimental aspects 10 of this problem. RPA has been classified into two modes: "hole-boring" 3,[11][12][13][14][15][16] (HB) and "light-sail" (LS).…”

Section: Introductionmentioning

confidence: 99%

Production of high energy protons with hole-boring radiation pressure acceleration

Robinson¹

2011

The possibility of producing energetic protons with energies in the range of 100–200 MeV via hole-boring (HB) radiation pressure acceleration (RPA) at intensities around 1021 W cm−2 is reexamined. It is found that hole-boring RPA can occur well below the relativistically corrected critical density in numerical simulations, with average proton energies in good agreement with established formulas. This suggests that protons in this energy range can be produced via HB RPA at around 1021 W cm−2. It is also shown that the prospects of doing this could be improved by using lasers of the same intensity but longer wavelength.

“…[1][2][3][4][5][6][7][8][9] Highquality ion beams have many prospective applications 5 including medical isotope production, tumor therapy, ultrafast radiography, and laser-driven fusion. Theoretical models and simulations based on one-dimensional (1D) geometry have shown that radiation pressure acceleration (RPA) 3,6,7 using circularly polarized (CP) laser pulses may be a promising route to obtaining high-quality monoenergetic ion beams in a much more efficient manner, compared to the target normal sheath acceleration (TNSA).…”

Section: Introductionmentioning

confidence: 99%

Conditions for efficient and stable ion acceleration by moderate circularly polarized laser pulses at intensities of 1020 W/cm2

Qiao¹,

Zepf²,

Gibbon³

et al. 2011

Self Cite

Conditions for efficient and stable ion radiation pressure acceleration (RPA) from thin foils by circularly polarized laser pulses at moderate intensities are theoretically and numerically investigated. It is found that the unavoidable decompression of the co-moving electron layer in Light-Sail RPA leads to a change of the local electrostatic field from a “bunching” to a “debunching” profile, ultimately resulting in premature termination of ion acceleration. One way to overcome this instability is the use of a multispecies foil where the high-Z ions act as a sacrificial species to supply excess co-moving electrons for preserving stable acceleration of the lower-Z ion species. It is shown by 2D particle-in-cell simulations that 100 MeV/u monoenergetic C6+ ion beams are produced by irradiation of a Cu–C-mixed foil with laser pulses at intensities 5 × 1020 W/cm2, which can be easily achieved by current day lasers.