COLLOQUIUM RE-SCHEDULED FROM JAN. 22 TO JAN 28
The study of plasma, a partially-ionized gas that is electrically conductive and able to be confined within a magnetic field, and how it releases energy.
The Sun emits a constant flow of particles from its surface. Mainly composed of Protons and electrons, and dragging with it magnetic fields, this Solar Wind expands outwards from the sun, interacting with planets and spacecraft alike. Since the 1960s, in situ observations have shown that the solar wind is comprised of two distinct states: slow (300550 km/s) and fast (600800 km/s). Temperature, density, and compositional variations between the two suggest different sources for the fast and slow solar wind.
Researchers at Princeton University and the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have launched a new center to study the volatile heliosphere — a complex and frequently violent region of space that encompasses the solar system. This region is carved out by the solar wind — charged plasma particles that constantly stream from the sun — and gives rise to space weather that can disrupt cell phone service, damage satellites and knock out power grids.
A key issue for the development of fusion energy to generate electricity is the ability to confine the superhot, charged plasma gas that fuels fusion reactions in magnetic devices called tokamaks. This gas is subject to instabilities that cause it to leak from the magnetic fields and halt fusion reactions.
Lyman Spitzer, Jr. made major contributions in several fields of astrophysics, plasma physics, and fusion energy. He invented the novel stellarator concept for confining plasmas for fusion, and was an early proponent of putting telescopes in space. This talk will briefly review some of Spitzer's pioneering contributions in fusion, including a pictorial history from his founding of PPPL to TFTR's achievement of 10 megawatts of fusion power. Prof. Kulsrud will provide some personal stories about his early days of working with Spitzer.
A multinational team led by Chinese researchers in collaboration with U.S. and European partners has successfully demonstrated a novel technique for suppressing instabilities that can cut short the life of controlled fusion reactions. The team, headed by researchers at the Institute of Plasma Physics in the Chinese Academy of Sciences (ASIPP), combined the new technique with a method that the U.S. Department of Energy’s Princeton Plasma Physics Laboratory (PPPL) has developed for protecting the walls that surround the hot, charged plasma gas that fuels fusion reactions.
The Lithium Tokamak eXperiment (LTX) will be discussed in the context of a more general program goal - to develop a compact realization of a tokamak fusion reactor. The general requirements for more compact tokamak reactors will be briefly discussed. The LTX project can investigate some, but not all, of these requirements, on a small scale. Recent results from LTX will be presented. Finally, the development of a toroidal system to test flowing liquid lithium walls, aimed at eventual implementation in a compact D-T tokamak, will be discussed.
Princeton astrophysicist Lyman Spitzer Jr. (1914-1997) was among the 20th Century’s most visionary scientists. His major influences range from founding the Princeton Plasma Physics Laboratory (PPPL) and its quest for fusion energy, to inspiring the development of the Hubble Space Telescope and its images of the far corners of the universe.