Fast-ion production from short-pulse irradiation of ethanol microdroplets.
We report on the first detailed measurements of ion energy distributions from microdroplet targets under ultrashort (100 fs), intense (10(16) Wcm(-2)) laser irradiation. Protons with kinetic energies of up to 20 keV are produced in a strongly anisotropic microexplosion. Modeling of the incident electromagnetic field indicates strong spatial variations over the surface of the microdroplet. Detailed numerical modeling shows that nonuniform heating on a submicron scale causes temperature inhomogeneities and nonradial pressure gradients, which drive an energetic nonspherical expansion.
Symes
D R
DR
The Blackett Laboratory, Imperial College of Science, Technology and Medicine, London SW7 2BZ, United Kingdom.
Comley
A J
AJ
Smith
R A
RA