Search

We describe an experiment on the interaction of a dipolar magnetic field with the laser plasma flow produced inside of a laboratory magnetosphere. This interaction is found to exhibit two dynamic stages: after a prompt displacement of the dipole field by the laser plasma, the magnetic field is captured and carried outside of the magnetosphere. The resultant data confirm the results of previous measurements carried out far beyond the magnetosphere and provide additional information about the new process of capturing the dipolar magnetic field by the internal magnetospheric plasma flow.

The limiting mode of the generation of low-frequency torsional whistlers is obtained for the first time. Laser plasma clouds create only weak whistlers in a weakly magnetized laboratory plasma (argon), allowing the whistler magnetic field to reach record values of ~25% of the background magnetic field.

An experimental study is performed of the collisionless interaction of plasma flows using spectral diagnostics. A monochromator with registration by a photo-electron multiplier (PMT) and a charge-coupled device (CCD) allows detection of ion acceleration as a laser plasma expands into a magnetized background plasma. The laser plasma ions show deceleration, the magnitude of which depends on the charge.

We report the results for the first complex experiment on the formation of an extended (up to ~0.5 m) plasma jet in a magnetic field (up to 300 G) in vacuum. The jet appears due to the injection of laser plasma bunches with a kinetic energy up to ~50 J across the magnetic field (in a solid angle Ω ≈ 1 sr) and a high degree of magnetisation of ions on the calculated scale field-induced deceleration of the bunch as a part of a sphere. A plastic target (polyethylene) has been irradiated by a CO2 laser in the most energy-efficient regime (near the plasma formation threshold), implemented at the expense of a wide radiation spot (diameter 2 – 3 cm) on the target. In a new-type model Super-Jet experiment on a large KI-1 facility at the Institute of Laser Physics, Siberian Branch, Russian Academy of Sciences (ILP SB RAS), the probe data on the internal structure and dynamics of plasma concentration and magnetic field strength in transverse jets, on the influence of instabilities and Hall effect have been obtained for the first time in laboratory modelling of space and astrophysical jets.

Combining such methods of plasma registration as spectral, probe and optical diagnostics, in this paper propagation of laser plasma in a vacuum magnetic field was studied. By means of Langmuir and magnetic probes such plasma parameters as velocity and the angle of expansion were measured, as well as the size of magnetic cavity. Using optical monochromator combined with CCD a Doppler broadening of a number of ionic and atomic lines was measured and the transversal speed of the plasma cloud expansion was calculated. The data plasma cloud propagation velocity and expansion angle obtained by two methods was compared with gated imaging data and magnetic probe measurements of cavity size.Combining such methods of plasma registration as spectral, probe and optical diagnostics, in this paper propagation of laser plasma in a vacuum magnetic field was studied. By means of Langmuir and magnetic probes such plasma parameters as velocity and the angle of expansion were measured, as well as the size of magnetic cavity. Using optical monochromator combined with CCD a Doppler broadening of a number of ionic and atomic lines was measured and the transversal speed of the plasma cloud expansion was calculated. The data plasma cloud propagation velocity and expansion angle obtained by two methods was compared with gated imaging data and magnetic probe measurements of cavity size.

Laboratory experiment on interaction of expanding laser produced plasma flow with magnetized background at conditions when gyroradius of ions rotation is comparable to characteristic scale of magnetic cavity is described. Practically important question on the influence of complex ion composition of plasma piston on the effectiveness of interaction at significantly super-Alfvenic velocities is investigated.

It was shown for the first time that in a laboratory experiment a train of laser plasma clouds makes it possible to increase the length of the whistler waves generated in the power tube of a magnetized medium. The intensity of waves is orders of magnitude higher than the level achieved by known methods.