The Max-Planck Princeton Center for Fusion and Astro Plasma Physics was created on March 29, 2012 through a cooperative agreement between the Max-Planck Society in Germany, and Princeton University. Below find more information about the center and its goals.
A plasma is a gas of charged particles (ions and electrons). Most of the visible matter beyond the Earth is a plasma, including stars, the interstellar medium (matter between the stars) and the intergalactic medium (matter between galaxies). On Earth, plasmas are important for producing energy through fusion reactions, as well as many other technologies.
The goal of the center is to understand several fundamental problems in plasma physics. Solving these problems could lead to new breakthroughs in producing clean and reliable fusion energy, as well as help us to understand the Universe in which we live.
Plasmas are permeated by magnetic fields. When oppositely directed fields are pushed together in a plasma, they reconnect, releasing energy and heating the plasma. Many violent processes in astrophysics are thought to be powered by reconnection, for example on the sun reconnection produces solar flares. However, the processes that control the rate of reconnection in a plasma are poorly understood. Through both experiments and theoretical modeling, members of the center are trying to understand magnetic reconnection.
Not all ions and electrons in a plasma have the same energy (move at the same speed). Some have much more energy than the average, and these are called energetic particles. They are observed on Earth as cosmic rays from interstellar space, and they are important source of cooling in fusion reactors. Energetic particles are thought to be produced by reconnection, or by shock waves in astrophysical plasmas. Members of the center are trying to understand the detailed physics which results in the production of energetic particles in plasmas, how those particles affect the dynamics of the plasma itself, and how such particles diffuse and transport energy through the plasma.
Much like the atmosphere, most plasmas are turbulent, that is they contain seemingly random fluctuations in velocity over a large range of scales. Turbulence in plasmas can have a variety of important effects. It can result in energy and momentum transport in fusion experiments.
In astrophysics, it can produce angular momentum transport and accretion of matter onto compact objects such as neutron stars and black holes, and it dominates the dynamics of the interstellar medium from which new generations of stars are born. Members of the center are studying the properties of turbulence in plasmas over a wide range of regimes.
Astrophysical Plasma Physics
There is an increasing appreciation that we cannot understand many of the astrophysical systems we observe through telescopes without understanding many aspects of plasma physics. For example, accretion of matter into black holes (which powers the most energetic events observed in the Universe) is controlled by plasma processes (the magneto-rotational instability, and turbulence).
The formation of cosmic rays requires understanding the acceleration of energetic particles in shocks. Understanding the death of massive stars in supernovae requires understanding gravitational collapse and radiation transfer in a plasma. All of these processes and more are studied by members of the center.
Fusion holds the promise to provide clean, safe, abundant energy. One of the most promising methods for producing fusion energy is through magnetic confinement of a very hot plasma.
On the other hand, most of the visible Universe is a plasma. The same processes that control accretion of matter into a black hole, or produce cosmic rays that hit the Earth, are also important in fusion devices.
By bringing together fusion scientists and astrophysicists to share expertise, computational tools, and experimental facilities, it is hoped that new discoveries in plasma physics will be accelerated.
A unique aspect of the center is the international collaboration it enables between Germany and the USA. In fusion science, members of the center will design are perform joint experiments on facilities such as the NSTX at PPPL in the USA, and Wendelstein 7-X stellerator at the IPP in Greifswald, Germany. Similarly, scientists will work together to develop and test the next generation of computer codes that can be used to model plasma dynamics in both fusion reactors and astrophysics.
Working together, scientists in both countries can achieve far more than working alone.