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We report on the generation of quasimonoenergetic electron beams by the laser wakefield acceleration of 17-50 TW, 30 fs laser pulses in pure neon gas jet. The generated beams have energies in the range 40-120 MeV and up to ~430 pC of charge. At a relatively high density, we observed multiple electron beamlets which has been interpreted by simulations to be the result of breakup of the laser pulse into multiple filaments in the plasma. Each filament drives its own wakefield and generates its own electron beamlet. [ABSTRACT FROM AUTHOR]

A laser wakefield acceleration (LWFA) experiment is performed using 30 TW, 30 fs, and 800 nm laser pulses, focused onto pure nitrogen plasma having relatively low densities in the range of 0.8 × 1018 cm-3 to 2.7 x 1018 cm-3 . Electron beams having a low divergence of ~3 mrad (fullwidth at half-maximum) and quasi-monoenergetic peak energies of ~105 MeV are achieved over 4-mm interaction length. The total electron beam charge reached to 2 nC, however, only 1%-2% of this (tens of pC) had energies >35 MeV. We tried different conditions to optimize the electron beam acceleration; our experiment verifies that lower nitrogen plasma densities are generating electron beams with high quality in terms of divergence, charge, pointing stability, and maximum energy. In addition, if LWFA is to be widely used as a basis for compact particle accelerators in the future, therefore, from the economic and safety points of view we propose the use of nitrogen gas rather than helium or hydrogen. [ABSTRACT FROM AUTHOR]