The many faces of the shear Alfven wave

November 8, 2010
This is a representation of the three-dimensional magnetic field (due to four currents threading the center of each helix) of a shear Alfvén wave. It was acquired at an instant of time throughout the volume of a large (60 cm diameter ,18m long) plasma in the LAPD device at UCLA. The currents and the field topology change in fractions of a millionth of a second. The sparkles are proportional to the electric field in the plasma induced by the wave. Credit: Walter Gekelman, UCLA

Scientists show that 3-D movies are no longer just for Hollywood blockbusters.

When physicists probe the mysteries of plasma, the fourth state of matter, they often discover of striking beauty. Much as when the sent back vivid images from space of ionized (an interstellar plasma), new 3D images of shear Alfvén waves are delighting both scientists and a new generation of science enthusiasts.

Plasmas support a large variety of waves. Some of these are familiar, such as light and sound waves, but a great many exist nowhere else. One of the fundamental waves in magnetized plasma is the shear Alfvén wave, named after Nobel Prize winning scientist Hannes Alfvén, who predicted their existence.

Shear waves of various forms have been a topic of experimental research for more than 15 years in the Large Device (LAPD) at the University of California, Los Angeles. When the waves were first studied, it was discovered that their creation gives rise to exotic spatial patterns, such as the one shown in Figure 1, all of them Shear Alfvén waves. Three-dimensional data, such as the magnetic field of the wave shown here, will be presented along with relevant theory. Part of the presentation will be in 3D.

It has become apparent that Alfvén waves are important in a wide variety of physical environments. They play a central role in the stability of the magnetic confinement devices used in fusion research, give rise to aurora formation in planets, and are thought to contribute to heating and ion acceleration in the solar corona. Shear waves can also cause particle acceleration over considerable distances in interstellar space.

Explore further: Scientists Explain Mysterious Plasma Jets On The Sun

Related Stories

Scientists Explain Mysterious Plasma Jets On The Sun

July 29, 2004

Scientists at the University of Sheffield and Lockheed Martin Solar and Astrophysics Lab have solved a 127-year-old problem about the origin of supersonic plasma jets (spicules) which continuously shoot up from the Sun. Their ...

Giant pipe organ in the solar atmosphere

April 19, 2007

Astronomers have found that the atmosphere of the Sun plays a kind of heavenly music. The magnetic field in the outer regions (the corona) of our nearest star forms loops that carry waves and behave rather like a musical ...

Sun's corona is both hot and kinky

March 6, 2008

Astrophysicists are having a heated debate over the wave structure of the Sun’s Corona - a debate which may one day influence solar weather forecasting and the theory behind fusion reactors.

Gravity Waves Make Tornados

March 19, 2008

Did you know that there's a new breakfast food that helps meteorologists predict severe storms? Down South they call it "GrITs."

Scientists find giant solar twists

March 19, 2009

(PhysOrg.com) -- Scientists have, for the first time, detected giant twisting waves in the lower atmosphere of the Sun, shedding light on the mystery of the Sun's corona (the region around the Sun, extending more than one ...

Cluster helps disentangle turbulence in the solar wind

October 4, 2010

From Earth, the Sun looks like a calm, placid body that does little more than shine brightly while marching across the sky. Images from a bit closer, of course, show it's an unruly ball of hot gas that can expel long plumes ...

Recommended for you

Seeing quantum motion

August 28, 2015

Consider the pendulum of a grandfather clock. If you forget to wind it, you will eventually find the pendulum at rest, unmoving. However, this simple observation is only valid at the level of classical physics—the laws ...

A little light interaction leaves quantum physicists beaming

August 24, 2015

A team of physicists at the University of Toronto (U of T) have taken a step toward making the essential building block of quantum computers out of pure light. Their advance, described in a paper published this week in Nature ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.