44th EPS Conference on Plasma Physics
P5.222
Generation of sub-MG quasi-stationary magnetic field using cm scale
capacitor-coil targets
D. Kumar1 , S. Singh1 , H. Ahmed2 , R. Dudzak3 , J. Dostal3 , T. Chodukowski4 , L. Giuffrida1 ,
P. Hadjisolomu2 , T. Hodge2 , J. Hrebicek3 , L. Juha3 , Z. Kalinowska4 , E. Krousky3 , M. Krus3 ,
P. Lutoslawski1 , M. De Marco1 , M. Pfeifer3 , J. Skala3 , J. Ullschmeid3 , T. Pisarczyk4 ,
M. Borghesi2 and S. Kar2
1
2
ELI Beamlines, Institute of Physics, Dolni Brezany, Czech Republic
School of Mathematics and Physics, Queen’s University Belfast, Belfast, United Kingdom
3
Prague Asterix Laser Facility, Institute of Plasma Physics, Prague, Czech Republic
4
Institute of Plasma Physics and Laser Microfusion, Warsaw, Poland
A controlled and strong magnetic field is extremely useful in various
laser plasma experiments with applications to fast ignition, laboratory
astrophysics and charged particle beam lensing. Mega Gauss (MG)
level quasi-stationary fields for such applications can be created by
the interaction of a kJ-ns class laser with a capacitor-coil target[1, 2].
Previous experiments used two parallel foils with lateral dimension
of several mm and a gap between the foils of a fraction of a mm. In
the experiment conducted at the Prague Asterix Laser Facility, the Iodine laser (600 J, 350 ps, Iλ 2 = 1016 − 1017 W/cm2 µm2 ) was used
to irradiate much larger (upto 2 cm lateral dimension) macroscopic
targets. With these large targets, the ablated plasma was about 3 cm
from the center of the coil, thus preventing damage to the coil or to
Figure 1: Example of the
measured Faraday rotation in degrees through a
0.5 mm thick TGG crystal
placed about 0.3 mm behind the coil. Inset shows
the TGG crystal used for polarimetry - an extremely desirable feature the target used for this
for developing future applications. Spatial distribution and temporal shot.
evolution of the magnetic field at the coil was characterized simultaneously by polarimetry technique at 2 different wavelengths - (a) imaging using a short pulse
probe beam of duration 30 fs and center wavelength 810 nm and (b) streaked using the 2ω probe
beam derived from the main pulse. Figure 1 shows an example of the data obtained from the fs
polarimetry imaging diagnostic. For coils of 1 mm diameter, magnetic fields of up to 0.3 MG
were measured in the experiment lasting for several ns.
References
[1] J. J. Santos et al, New J. Phys. 17, 083051 (2015)
[2] L. Gao et al, Phys Plasmas 23, 043106 (2016)