Browse Physics

Where do cosmic magnetic fields come from?

Plasma chamber offers a laboratory-scale view of magnetic field eruptions on the sun’s surface.

A new phonon mode has been observed in a two-dimensional plasma crystal.

The magnetic field generated by a plasma can lack cylindrical symmetry even when the initial plasma state is perfectly symmetrical.

New satellite measurements may help solve the puzzle of how the sun’s energy heats the corona and solar wind.

The same instability that is observed in hot plasmas, such as those created in spacecraft ion thrusters, is also found in an ultracold xenon plasma.

Plasmas are normally thought of as high temperature ionized gases or fluids, such as those in the sun’s corona or those found in controlled nuclear fusion experiments. Many interesting plasma phenomena can occur, however, in plasmas at low temperature. With the help of laser trapping and cooling, atoms can be photoionized to form neutral plasmas at extremely low temperatures. These plasmas may exist in the so-called strong coupling regime, where the energy of the Coulomb interactions between particles is larger than their thermal energy. In addition to providing a test bed for studying the strongly coupled plasmas such as those found in Jovian planets and white dwarfs, ultracold plasmas play a critical role in understanding the formation of antihydrogen.

Magnetic field lines in moving plasmas can break and reform, releasing large amounts of energy. Simulations suggest this happens in a two stage process—one slow and smooth, the other rapid and chaotic.

Producing terahertz-frequency radiation with a hair-thin, laser-produced plasma could allow for remote illumination and imaging.

Researchers directly measured the time-varying field during a spark-like electrical breakdown that formed a plasma.

A new theory may explain what triggers solar flares, explosions of solar energy that can affect earthly communications.

A simple arrangement of electric and magnetic fields causes plasma to form shapes reminiscent of the jets generated near supermassive black holes.

Cleverly arranged electromagnetic fields could form a ‘one-way door’ that allows electrons through on one side but repels them from the other.

Bombarding aluminum with protons provides a glimpse of warm dense plasma, a rarely observed form of matter.

The mystery of the sun’s blazing corona may be partially solved by a theory describing how magnetic events lead to heating at the corona’s base.

A plasma lens focuses a high energy beam of positrons.

An ultracold plasma can form spontaneously from a cloud of cold, excited atoms.

Physicists have used an artificial aurora to illuminate a layer of the ionosphere that has been difficult to observe.

Researchers have demonstrated a new way to make high frequency coherent light. A similar process could lead to a compact source of coherent x rays.

Physicists have successfully tested a technique for driving current in fusion-based electric power plants of the future.