Energetic electron propagation in solid targets driven by the intense electric fields of femtosecond laser pulses

Journal Article · Wed Jun 15 00:00:00 EDT 2011 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3596538· OSTI ID:21546962

Seely, J F ^[1]; Szabo, C I ^[2]; Audebert, P; Brambrink, E ^[3]

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1. Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, DC 20375 (United States)
2. Artep, Inc., 2922 Excelsior Spring Circle, Ellicott City, Maryland 21042 (United States)
3. Laboratoire pour L'Utilisation des Lasers Intenses (LULI), Ecole Polytechnique, 91128 Palaiseau Cedex (France)

An analytical model is used to interpret experimental data on the propagation of energetic electrons perpendicular to and parallel to the propagation direction of intense femtosecond laser pulses that are incident on solid targets. The pulses with {approx_equal}10{sup 20} W/cm{sup 2} intensity are incident normal onto a gadolinium or tungsten wire embedded in an aluminum substrate, and MeV electrons generated in the focal spot propagate along the laser direction into the irradiated wire. Electrons also propagate laterally from the focal spot through the aluminum substrate and into a dysprosium or hafnium spectator wire at a distance up to 1 mm from the irradiated wire. The ratio of the K shell emission from the spectator and irradiated wires is a measure of the numbers and energies of the MeV electrons propagating parallel to and perpendicular to the intense oscillating electric field of the laser pulse. It is found that the angular distribution of electrons from the focal spot is highly non-isotropic, and approximately twice as many electrons are driven by the electric field toward the spectator wire as into the irradiated wire. This quantitative result is consistent with the qualitative experimental observation that the oscillating electric field of an intense femtosecond laser pulse, when interacting with a heavy metal target, preferentially drives energetic electrons in the electric field direction as compared to perpendicular to the field.

• OSTI ID: 21546962
• Journal Information: Physics of Plasmas, Vol. 18, Issue 6; Other Information: DOI: 10.1063/1.3596538; (c) 2011 American Institute of Physics; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ANGULAR DISTRIBUTION
CHARGED-PARTICLE TRANSPORT
DYSPROSIUM
ELECTRIC FIELDS
EMISSION
GADOLINIUM
HAFNIUM
K SHELL
LASERS
SUBSTRATES
TAIL ELECTRONS
TUNGSTEN
WIRES
DISTRIBUTION
ELECTRONIC STRUCTURE
ELECTRONS
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
LEPTONS
METALS
RADIATION TRANSPORT
RARE EARTHS
REFRACTORY METALS
TRANSITION ELEMENTS