Author Topic: diocotron instabilities  (Read 9249 times)

electrobleme

  • Administrator
  • Plasma Star
  • *****
  • Posts: 1501
  • EUreka?: +1/-0
  • It's time to step out of the Gravity, Well?
    • Electric Universe theory blog
diocotron instabilities
« on: June 06, 2010, 17:55:50 »

diocotron instabilities

theres not to much about diocotron instabilities out there that i can understand or is useful when thinking about the Electric Universe! but here is the main stuff and images that i have found so far



diocotron instability stages experiment image



diocotron instability vortices with electron beam


diocotron instability vortices



diocotron instabilities cross section and showing inside circle


Quote
Diocotron instability

The diocotron instability (also called the slipping stream plasma instability), is "one of the most ubiquitous instabilities in low density nonneutral plasmas with shear in the flow velocity [.. that can ..] occur in propagating nonneutral electron beams and layers".[2] [3] It may give rise to electron vortices,[4], which resembles the Kelvin-Helmholtz fluid dynamical shear instability, and occurs when charge neutrality is not locally maintained.[5] The term diocotron derives from the Greek, meaning "pursue."[5]

Aurora

Although usually attributed to Kelvin Helmholtz instabilities,[6] the diocotron instability has been associated with the aurora (where they are known as auroral curls or auroral vortices), the mechanism having been proposed by Hannes Alfvén in 1950.[5][7]


Galactic arms

The arms of galaxies (eg. NGC 3646) are susceptible to the diocotron instability [8] In the simulation of galaxy formation, Peratt found that:

Since Ez is out of the plane of the page, the column electrons spiral downward in counter-clockwise rotation while the column ions spiral upward in clockwise rotation. A polarization induced charge separation also occurs in each arm, which, as it thins out, produces a radial electric field across the arm. Because of this field, the arm is susceptible to the diocotron instability. This instability appears as a wave motion in each arm.[9]

Pulsars

The Diocotron instability has also been associated with a pulsar's electrosphere.[10]

Diocotron instability | plasma-universe.com


Quote
... A plasma instability is created by two sheets of charge slipping past each other. Energy is dissipated in the form of two surface waves propagating in opposite directions, with one flowing over the other... Wind creates fluid dynamic instabilities of its own and it's important not to confuse the two. Diocotron instabilities are inherently short-lived because plasma discharges are short-lived.
Is Storm Alley on Saturn a diocotron instability? | thunderbolts.info



Quote
Diocotron instability: If for some reason a separation of electric charge in the radial direction of the pinch occures, there appears a non-zero electric field which, together with the axial magnetic field Bz  produces a drift of the azimuthal velocity v?. The entire pinch then begins to rotate with differential rotation (the zones at different distances from the axis rotate with different velocity). In the surface of the pinch two zones, with different velocity, become neighbors (the pinch which rotates and its surrounding media) and can lead into an instability known from observations in fluids. We call this diocotron instability. The typical consequence is a modification of the pinch surface into a vortex structure.

Diocotron instability | aldebaran.cz





« Last Edit: June 06, 2010, 20:52:32 by electrobleme »

electrobleme

  • Administrator
  • Plasma Star
  • *****
  • Posts: 1501
  • EUreka?: +1/-0
  • It's time to step out of the Gravity, Well?
    • Electric Universe theory blog
diocotron instability - creating Saturns North Pole hexagon
« Reply #1 on: June 06, 2010, 20:51:59 »


diocotron instability - creating Saturns North Pole hexagon



Saturns North Pole Hexagon showing and forming by a diocotron instability



diocotron instability at Saturns and its north polar temperatures



diocotron instability at Saturns North Pole Hexagon and Aurora


Quote


4. Saturn's north polar hot spot and the Electric Universe "experimentum crucis."
In Science, Feb 4, 2005, the W. M. Keck Observatory reported the discovery of a south polar hot spot on Saturn. See The Spiral Galaxy at Saturn's Pole. Saturn's south pole is presently lit by the Sun but it was not expected to be the hottest place on the planet! Saturn's north pole has been in darkness since 1995, which prompted Dr. Orton to remark: "One of the obvious questions is whether Saturn's north pole is anomalously cold and whether a cold polar vortex has been established there."


>> Saturn's North Pole Hexagon and Aurora. This night-time view of Saturn's north pole by the visual and infrared mapping spectrometer on NASA's Cassini orbiter reveals a dynamic, active planet at least 75 kilometers (47 miles) below the normal cloud tops seen in visible light. Clearly revealed is the bizarre six-sided hexagon feature present at the north pole. Credit: NASA/JPL/University of Arizona.

The following day I posted the news "Saturn's Strange Hot Spot Explained." In it I made the following statement:
"The Electric Universe predicts, experimentum crucis, that BOTH poles should be hot, not one hot and the other cold." That extraordinary prediction was confirmed in a report in Science on Jan 4. Such unusual predictions have become a hallmark of the Electric Universe paradigm and establish it as a first class theory. The bizarre long-lived hexagonal feature is a mystery to astronomers. Ground-based observations published in Science, April 16, 1993, prompted the remark, "The large lifetime of cloud features poleward of ~74?N seems amazing in view of the strong seasonal insolation cycle at these latitudes."


>> Orthographic projection of Saturn's north polar temperatures in the troposphere at 100 mbar. The polar hot spot is clearly visible along with the hexagonal structure at 79?N. Credit: L. N. Fletcher et al., U. of Oxford, UK.

The polar hot spot and long-lived hexagonal feature results from a continuous electric current flowing from the Sun into the pole of Saturn. The hot spot will remain for as long as the Sun shines electrically. The blue (false color) auroral ring shows that the current flows into Saturn via a cylindrical electron beam propagating along Saturn's magnetic field and magnetically pinching (known as a Z-pinch) down to the polar region.

>>Depiction of an intense auroral funnel. The oblique upward view shows both down-flowing and up-flowing Birkeland current filaments contained within two concentric cylindrical sheets. The Z-pinch core is shown (purple).
"The auroral plasma column is susceptible to two plasma instabilities; hollowing of the relativistic electron beam to form the sheets and the diocotron instability that cause the sheets to filament into individual current strands causing the "swirls" or "curtains." These instabilities also produce the radiation observed over a wide range of the electromagnetic spectrum."
— A. Peratt. Characteristics For The Occurrence Of A High-Current, Z-Pinch Aurora, (PDF 6.6 Mb) IEEE Transactions On Plasma Science, Vol. 31, No. 6, December 2003.

Birkeland current filamentation can be seen best in the top quadrants of Saturn's blue auroral ring. The cylindrical auroral beam is subject to vortex formation, known as 'diocotron instabilities.' Historically, vortex structure and vortex interactions in charged particle beams have been known since the turn of the 19th century when Kristian Birkeland first photographed the passage of particle beams through low vacuum in his terrella cathode experiments. Neighbouring vortices are subject to long-range attractive and short-range repulsive forces, which result in a departure of the discharge pattern from a circle to a polygon.

The diocotron instabilities in the inner current cylinder are forcing the cloud pattern to form the distinctive hexagonal shape. The polar hot spot is heated by the Birkeland current discharge in the core of the Z-pinch.

It is important to note that Jupiter has been found to have a hexagonal cloud collar at its north pole. And Neptune, the most distant planet from the Sun, has a hot pole. These discoveries show that these planets are connected electrically to the Sun's circuit and real power source—the galaxy. Jupiter's Great Red Spot occasionally shows clear hexagonal morphology too, which indicates that it is an electrical tornado connected to some surface electrical anomaly beneath the clouds.
2008—Year of the Electric Universe | holoscience.com