2 research outputs found
Investigation of ultraintense femtosecond laser–plasma interactions through ω and 2ω imaging and spectroscopy
A laser–plasma interaction experiment was performed
in order to match effective conditions for wake-field electron
acceleration. A 30-fs pulse was made to interact with a
preformed plasma generated via the exploding foil technique
from a 1-μm-thick plastic film. The irradiance of the
femtosecond pulse in the plasma was 1020
Wcm−2. The interaction conditions were
investigated via imaging and spectroscopy at the fundamental
and the second harmonic of the laser frequency, both forward
and backward. Our data clearly show that conditions suitable
for electron acceleration are achieved close to the propagation
axis and can be easily reproduced from shot to shot. In contrast,
significant growth of instabilities occurs at the boundaries
of the interaction region. These observations are consistent
with a preliminary evidence of forward acceleration of high-energy
electrons. Optical, X-ray, and γ-ray data obtained for different
positions of the foil target with respect to the laser focal plane
further support this promising scenario