  Measurements are reported of the target neutralization current, the target
charge, and the tangential component of the magnetic field generated as a
result of laser-target interaction by pulses with the energy in the range of 45
mJ to 92 mJ on target and the pulse duration from 39 fs to 1000 fs. The
experiment was performed at the Eclipse facility in CELIA, Bordeaux. The aim of
the experiment was to extend investigations performed for the thick (mm scale)
targets to the case of thin (micrometer thickness) targets in a way that would
allow for a straightforward comparison of the results. We found that thin foil
targets tend to generate 20 to 50 percent higher neutralization current and the
target charge than the thick targets. The measurement of the tangential
component of the magnetic field had shown that the initial spike is dominated
by the 1 ns pulse consistent with the 1 ns pulse of the neutralization current,
but there are some differences between targets of different type on sub-ns
scale, which is an effect going beyond a simple picture of the target acting as
an antenna. The sub-ns structure appears to be reproducible to surprising
degree. We found that there is in general a linear correlation between the
maximum value of the magnetic field and the maximum neutralization current,
which supports the target-antenna picture, except for pulses hundreds of fs
long.
