Tabletop Particle Acceleration
With their intense fields, lasers are able to accelerate electrons to relativistic velocities in very small lengthscales. This occurs over such a small timescale that ion movement is negligible and extremely large fields form from the charge separation. Manipulating this charge separation enables acceleration of electrons and ions to energies to the MeV or GeV level. A university-scale laser can accelerate electrons to the same energies as a 100-meter, $100 million dollar synchrotron. Through the strongly nonlinear interaction secondary processes can be utilized to generate high brightness, MeV beams of neutrons or even beams of positrons. |
Coherent X-ray Generation
Light is produced by the acceleration of charged particles, and the very large, nonlinear acceleration that occurs in intense laser interactions provides a means for upconverting optical light to very high frequencies. The x-rays produced have some unique properties that enable unique spectroscopies, such as pulse durations on the order of single femtoseconds or less; and being spatially coherent so that the x-rays have laser like properties. Applications such as elemental specific dynamic studies and phase contrast imaging are possible with these sources. X-rays are produced from several different mechanisms from varying intensity regimes, and can have a wide variety of energies spanning from tens of eV to tens of keV. |
The relativistic interactions make it difficult to gain a full understanding of the interaction from diagnostics alone. Combining relativistic electrodynamics with non-equilibrium plasma physics innate in these interactions requires modeling very nonlinear, highly coupled systems. To this extent, complex numerical simulations are required in order to gain insight into the interaction and make meaningful predictions. The use of radiation hydrodynamics, Monte Carlo, and particle-in-cell simulations enable numeric modeling of a wide subset of interactions and can provide insight that is difficult or impossible without. Indeed, tabletop acceleration was born from a simulation performed years before such experiments were performed. |