Measurements of the inverse Faraday effect from relativistic laser interactions with an underdense plasma.
Magnetic fields in excess of 7 MG have been measured with high spatial and temporal precision during interactions of a circularly polarized laser pulse with an underdense helium plasma at intensities up to 1x10(19) W cm(-2). The fields, while of the form expected from the inverse Faraday effect for a cold plasma, are much larger than expected, and have a duration approaching that of the high intensity laser pulse ( <3 psec). These observations can be explained by particle-in-cell simulations in 3D. The simulations show that the magnetic field is generated by fast electrons which spiral around the axis of the channel created by the laser field.
Najmudin
Z
Z
Imperial College of Science, Technology & Medicine, Prince Consort Road, London SW7 2BZ, United Kingdom.
Tatarakis
M
M
Pukhov
A
A
Clark
E L
EL
Clarke
R J
RJ
Dangor
A E
AE
Faure
J
J
Malka
V
V
Neely
D
D
Santala
M I
MI
Krushelnick
K
K