 |
| |
|
General Information
|
Pulsed-power-based sciences encompass areas of research that that make use of pulsed power generators, machines that produce submicrosecond electrical pulses at the level of >1010 W. The Laboratory of Plasma Studies (LPS) at Cornell University has been involved in many aspects of pulsed-power-based-plasma sciences since the Laboratory's inception in 1967. Early research generation of electron and ion beams at the 1010 to 1012 W power levels and their interaction with gases and plasmas. Applications of interest include magnetic and inertial confinement fusion and high power microwave pulse generation. At the present time, the FIREX experiment (Field-reversed ion ring experiment) carries on the LPS tradition of excellence in intense ion beam experiments for application to magnetic confinement fusion.
In recent years our research emphasis has shifted in the direction studies of high energy density plasma studies, including exploding fine metal wires, typically 25µm in diameter, with currents as high as 500,000 Amperes. Among the interesting results from such experiments are that we have been able to observe, using x-ray radiography, that the wires pass through a mixed (liquid-vapor) phase stage as a result of plasma formation around the wires before the wires are fully vaporized. Both the mixed phase wire stage and the ability to generate the very short diagnostic x-ray pulse from a tiny (~1µm) hot (~10,000,000K) plasma produced by exploding two crossed wires (see below) have turned out to be very interesting aspects of our research.
The Center for the Study of Pulsed-Power-Driven High Energy Density Plasmas has been established to enable us to continue and even expand our studies of exploding wires and their applications. This work is being carried out in collaboration with researchers at Imperial College, London, the University of Nevada, Reno, the Weizmann Institute of Science in Israel and the P.N. Lebedev Physical Institute in Moscow. In addition, we will expand our range of applications of pulsed-power-driven high energy density science to include isentropic compression experiments that take advantage of the ultra-high magnetic pressures that can be generated with a 1,000,000 Ampere pulsed power generator. We will also be looking for additional practical applications, (such as in the biological or medical sciences) of the high resolution x-ray imaging capability that we have developed for the exploding wires.
The Center for Pulsed-Power-Driven High Energy Density Plasma Studies is funded through a Cooperative Agreement with the Department of Energy and its National Nuclear Security Administration (NNSA). High energy density, rapidly evolving plasmas are central to the NNSA stockpile stewardship program. For some important high energy density plasma (HEDP) applications, pulsed-power generators are the most cost-effective way to produce the desired experimental conditions. This is the case for generating high energy, short pulse x-ray sources for inertial confinement fusion studies. The Sandia National Laboratories, Albuquerque, uses their Z-machine, a 20 million Ampere pulsed power generator, explode cylindrical arrays of metal wires to generate up to 2 million Joules of x-rays [Gerold Yonas, Scientific American, August 1998, p. 40]. The Sandia experiments motivated our initial studies of individual exploding wire dynamics at Cornell, and the are the reason why the Imperial College, London, group with which we collaborate in the Center initiated its studies of circular arrays of exploding wires.
|
|
| |
|
|