High quality electron bunch generation with CO2-laser-plasma interaction

Abstract

CO 2 laser-driven electron acceleration is demonstrated with particle-in-cell simulation in low-density plasma. An intense CO 2 laser pulse with long wavelength excites wakefield. The bubble behind it has a broad space to sustain a large amount of electrons before reaching its charge saturation limit. A transversely propagating inject pulse is used to induce and control the ambient electron injection. The accelerated electron bunch with total charge up to 10 nC and the average charge per energy interval of more than 0.6 nC/MeV are obtained. Plasma-based electron acceleration driven by intense CO 2 laser provides a new potential way to generate high-charge electron bunch with low energy spread, which has broad applications, especially for X-ray generation by table-top FEL and bremsstrahlung.

Extending laser plasma accelerators into the mid-IR spectral domain with a next-generation ultra-fast CO2laser

“…rel that can reach more than 3 nC for a 100 TW-class CO 2 laser, in contrast to just hundreds of pC with a solid-state laser. This estimate agrees with recent simulations where 5.7 nC bunches are trapped and accelerated by crossing two CO 2 laser pulses with a 0 = 2 in in plasma of 3 × 10 16 cm −3 electron density [19]. Simultaneously, having a bigger size plasma bubble simplifies achieving controlled external charge injection, providing a convenient test-bed for exploring beam loading effects and precise phasing into the wake of preformed femtosecond electron bunches injected from conventional accelerators, such as with the photocathode linac available at ATF [7].…”

“…The linear dimensions of the plasma-bubble structure also grow in proportion to λ, approximately tenfold, so supporting higher accelerated charges estimated by mono ≈ that can reach more than 3 nC for a 100 TW-class CO 2 laser, in contrast to just hundreds of pC with a solid-state laser. This estimate agrees with recent simulations where 5.7 nC bunches are trapped and accelerated by crossing two CO 2 laser pulses with a 0 =2 in in plasma of 3×10 16 cm -3 electron density [19].…”

Direct acceleration of electrons by a CO2 laser in a curved plasma waveguide

“…Nowadays, high-pressure CO 2 laser has already reached multi-Terawatt-level 9 and been successfully applied for a series of proton acceleration experiments. 10,11 However, it has been less progresses in CO 2 laser-driven wakefield acceleration, 12,13 mainly because of the difficulty with building ultra-short CO 2 laser system. In general, it is well known that the longitudinal dimension of the driver of plasma wakefield should be comparable to plasma wavelength in order to resonantly excite a bubble, 3,14,15 such that for the typical CO 2 laser pulse duration (τ ∼ 10 ps), an extremely low-density plasma (n e ∼ 10 13 cm −3 ) is required, which is of little interest to the accelerator community since the maximum acceleration gradient (i.e.…”