Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userLaser electron acceleration on curved surfaces
63
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
Electron acceleration by relativistically intense laser beam propagating along a curved surface allows to split softly the accelerated electron bunch and the laser beam. The presence of a curved surface allows to switch an adiabatic invariant of electrons in the wave instantly leaving the gained energy to the particles. The efficient acceleration is provided by the presence of strong transient quasistationary fields in the interaction region and a long efficient acceleration length. The curvature of the surface allows to select the accelerated particles and provides their narrow angular distribution. The mechanism at work is explicitly demonstrated in theoretical models and experiments.
rate research
Read More
A detailed study of direct laser-driven electron acceleration in paraxial Laguerre-Gaussian modes corresponding to helical beams $text{LG}_{0m}$ with azimuthal modes $m=left{1,2,3,4,5right}$ is presented. Due to the difference between the ponderomotive force of the fundamental Gaussian beam $text{LG}_{00}$ and helical beams $text{LG}_{0m}$ we found that the optimal beam waist leading to the most energetic electrons at full width at half maximum is more than twice smaller for the latter and corresponds to a few wavelengths $Delta w_0=left{6,11,19right}lambda_0$ for laser powers of $P_0 = left{0.1,1,10right}$ PW. We also found that for azimuthal modes $mgeq 3$ the optimal waist should be smaller than $Delta w_0 < 19 lambda_0$. Using these optimal values we have observed that the average kinetic energy gain of electrons is about an order of magnitude larger in helical beams compared to the fundamental Gaussian beam. This average energy gain increases with the azimuthal index $m$ leading to collimated electrons of a few $100$ MeV energy in the direction of the laser propagation.
We study and discuss electron acceleration in vacuum interacting with fundamental Gaussian pulses using specific parameters relevant for the multi-PW femtosecond lasers at ELI-NP. Taking into account the characteristic properties of both linearly and circularly polarized Gaussian beams near focus we have calculated the optimal values of beam waist leading to the most energetic electrons for given laser power. The optimal beam waist at full width at half maximum correspond to few tens of wavelengths, $Delta w_0=left{13,23,41right}lambda_0$, for increasing laser power $P_0 = left{0.1,1,10right}$ PW. Using these optimal values we found an average energy gain of a few MeV and highest-energy electrons of about $160$ MeV in full-pulse interactions and in the GeV range in case of half-pulse interaction.
A set of ballpark parameters for laser, plasma, and accelerator technologies that define for electron energies reaching as high as TeV are identified. These ballpark parameters are carved out from the fundamental scaling laws that govern laser acceleration, theoretically suggested and experimentally explored over a wide range in the recent years. In the density regime on the order of 10^{16} cm^{-3}, the appropriate laser technology, we find, matches well with that of a highly efficient high fluence LD driven Yb ceramic laser. Further, the collective acceleration technique applies to compactify the beam stoppage stage by adopting the beam-plasma wave deceleration, which contributes to significantly enhance the stopping power and energy recovery capability of the beam. Thus we find the confluence of the needed laser acceleration parameters dictated by these scaling laws and the emerging laser technology. This may herald a new technology in the ultrahigh energy frontier.
Dynamics of self-injected electron bunches has been numerically simulated in blowout regime at self-consistent change of electron bunch acceleration by plasma wakefield, excited by a laser pulse, to additional their acceleration by wakefield, excited by self-injected bunch. Advantages of acceleration by pulse train and bunch self-cleaning have been considered.
Laser wakefield accelerators rely on the extremely high electric fields of nonlinear plasma waves to trap and accelerate electrons to relativistic energies over short distances. When driven strongly enough, plasma waves break, trapping a large population of the background electrons that support their motion. This limits the maximum electric field. Here we introduce a novel regime of plasma wave excitation and wakefield acceleration that removes this limit, allowing for arbitrarily high electric fields. The regime, enabled by spatiotemporal shaping of laser pulses, exploits the property that nonlinear plasma waves with superluminal phase velocities cannot trap charged particles and are therefore immune to wave breaking. A laser wakefield accelerator operating in this regime provides energy tunability independent of the plasma density and can accommodate the large laser amplitudes delivered by modern and planned high-power, short pulse laser systems.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
