Experiments with two ropes of different diameters and energy were done and three-dimensional (3D) plasma flows measured. Ion and electron heating of the ropes was documented and multiple QSL's were identified when three ropes were present. These experiments have identified a quasi-separatrix layer (QSL) for the first time. Experiments on two and three flux ropes resumed at UCLA in 2005 and have been previously reported.
Permute random rope define free#
The ropes twisted about one another because of their mutualįorces and then merged into a force free state. The first UCLA experiment, done over 20 years ago studied two ropes that were not kink unstable. There was no background plasma but probes were used to measure magnetic fields, temperature and density in the device and the results were compared with models. An experiment at LANL, which produced two kink unstable flux ropes using plasma guns to generate them, revealed magnetic field line reconnection when the ropes collided. Magnetosonic waves were radiated into the background plasma when this occurred.
Plasma when injected at the rope footprints trigger the eruption of the flux rope. Experiments at UCLA with a high repetition rate and a background plasma independent of the ropes allowed for magnetic field measurements. These experiments, nevertheless, generated a great deal of interest because the ropes were seen to erupt as coronal mass ejections (CMEs) do. Much of the diagnostics involved imaging by fast cameras but extensive probe measurements of the fields was not possible because of shot-to-shot reproducibility. There was no background plasma and the rope plasma was generated by the arc. Using a plasma arc in a horse shoe shaped magnetic field unstable flux ropes have been studied by Bellan et al. The first involves the generation of arched ropes to simulate what is happening near the surface of the sun. Broadly speaking experiments fit into two classes. The reason for this is simple, they are difficult to set up, and diagnose. ĭespite a great deal of interest in this field there have been very few experiments on flux ropes. The study of these objects is so rich that it has involved solar and space plasma physicists, experimentalists, those doing simulations, and topologists. The resulting motion can be violent enough to make them collide and produce bursts of magnetic field line reconnection. Under the right conditions individual ropes can be subject to the kink instability.
Permute random rope define series#
Current sheets (which can be considered to be flux rope slabs), such as those observed in the Earth's magnetotail can become unstable and tear into a series of nearly linear ropes which can interact and braid with one another. Their signature caused by light emitted by electrons moving along magnetic field lines have been recorded in ultraviolet (UV) and soft x-ray satellite photographs of the Sun. Sometimes large magnetic ropes are ejected from the Sun and if the timing and ejection are right they may come all the way to the Earth where they are detected by probes on satellites. Flux ropes routinely occur near the surface of the Sun and in all probability every other star. In instances when they do collide magnetic field can be partially converted to other forms of energy such as flows, heat, fast particles and waves. The interaction results in the ropes twisting about each other, colliding and sometimes merging. If the magnetic ropes have strong enough magnetic fields they can mutually interact.
There are quite a few situations where multiple flux ropes exist simultaneously.
Magnetic flux ropes are twisted bundles of electrical current and magnetic field which can exist in magnetized plasmas. The Lyapunov and Hurst exponents are calculated and the complexity and permutation entropy of the flows and field components are shown throughout the volume. The complexity is a function of space and time. The location of data on this map indicates if the magnetic fields are stochastic, or fall into regions of minimal or maximal complexity. The permutation entropy can be calculated from the time series of the magnetic field data (this is also done with flows) and is used to calculate the positions of the data on a Jensen–Shannon complexity map. Conditional averaging is possible for only a number of rotation cycles as the field line motion becomes chaotic. Three-dimensional magnetic field lines are computed by conditionally averaging the data using correlation techniques. Each collision results in magnetic field line reconnection and the generation of a quasi-separatrix layer. They are kink unstable and smash into one another as they move. Magnetic flux ropes immersed in a uniform magnetoplasma are observed to twist about themselves, writhe about each other and rotate about a central axis.
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