Guided propagation of short intense laser pulses and electron acceleration

Abstract

The dynamics of a guided laser pulse propagation and wakefield generation in plasma channels, ionizing gases and gas filled capillaries is investigated. The efficient generation of a regular wakefield over long distances suitable for laser wakefield accelerators is demonstrated. The different schemes of electron bunch injection and compression to provide monoenergetic electron acceleration to high energies are analysed. A possibility of effective multistage acceleration of short electron bunches with low emittance and energy spread is demonstrated. The analytical results are confirmed by the results of numerical modelling.

Coupling Efficiency of Intense Laser Pulses to Capillary Tubes for Laser Wakefield Acceleration

“…The normalized ionization current G (ion) in (1) can be explicitly expressed through the zero harmonics (of the laser frequency ω 0 ) of the ionization source describing the optical field ionization using the envelope amplitude of the laser pulse by averaging the ADK formula [14], [15] over a laser period in the equations of ionization kinetics [11], [12], [16].…”

“…In the quasi-static approximation [17], the relativistic plasma response n/γ can be expressed through a single scalar function (potential) Φ [11], [12] …”

“…For the numerical modeling of the laser pulse propagation in a gas-filled (or vacuum) comparatively wide cylindrical capillary (r ≤ R cap , k 0 R cap 1) with varying radius R cap (z), the following boundary condition at the capillary wall r = R cap (z) was used [11], [12]:…”

Acceleration of electron bunches injected into a wake wave

“…In [13][14][15][16][17], an injection scheme was considered in which an electron bunch is injected into a plasma channel ahead of the laser pulse generating the wake wave; in this case, the velocity of the injected bunch must be lower than the phase velocity of the wake wave. It was shown that, after the trapping stage, the bunch length could decrease by several hundred times.…”

“…It was shown that, after the trapping stage, the bunch length could decrease by several hundred times. This makes it possible to accelerate electron bunches generated by modern injectors up to energies of 1 GeV, the electron energy spread being as low as 0.1% [15,17]. An important feature of this scheme is that electrons are injected into the spatial region free of external fields.…”