- Hakimi, Sahel;
- Bulanov, Stepan S;
- Huebl, Axel;
- Obst-Huebl, Lieselotte;
- Nakamura, Kei;
- Gonsalves, Anthony;
- Schenkel, Thomas;
- Tilborg, Jeroen van;
- Vay, Jean-Luc;
- Schroeder, Carl B;
- Esarey, Eric;
- Geddes, Cameron R
The interaction of an ultra-intense laser pulse with a near critical density
target results in the formation of a plasma channel, a strong azimuthal
magnetic field and moving vortices. An application of this is the generation of
energetic and collimated ion beams via Magnetic Vortex Acceleration. The
optimized regime of Magnetic Vortex Acceleration is becoming experimentally
accessible with new high intensity laser beamlines coming online and advances
made in near critical density target fabrication. The robustness of the
acceleration mechanism with realistic experimental conditions is examined with
three-dimensional simulations. Of particular interest is the acceleration
performance with different laser temporal contrast conditions, in some cases
leading to pre-expanded target profiles prior to the arrival of the main pulse.
Preplasma effects on the structure of the accelerating fields is explored,
including a detailed analysis of the ion beam properties and the efficiency of
the process. Improved scaling laws for the MVA mechanism, including the laser
focal spot size effects, are presented.