Jeudi 26 Mai
Résumé :
The Laboratory of Plasma Studies, Cornell University has been studying High
Energy Density (HED) plasmas produced by 1011-1012 Watt pulsed power
machines for many years. At the present time, our research includes fundamental studies and applications of HED plasmas in several configurations, but
all produced by passing up to 1 MA of current through fine (e.g., 25 µm) metal
wires or thin (e.g., 5 µm) metal foils. The resulting plasmas are as high density
and temperature as 1022/cm3 and 1.5 keV, respectively, with very short life,
<< 1 ns. Alternatively, they may last as long as a few hundred nanoseconds
at a density of 1019/cm3 or more and a temperature of a few tens of eV.
We are studying fundamental aspects of these plasmas, such as their radiative
properties and stability, as well as their applications. For example the very
short-lived, hot plasma, called an X pinch, is also very tiny and can be used
for point projection radiography ; the longer-lived plasmas can be used for
laboratory plasma astrophysics. We also devote considerable effort to diagnostic development for HED plasmas, such as X-ray absorption spectroscopy to
determine plasma density, temperature and ionization state as a function of
position. Some measurements are sufficiently accurate that they can be used
to check atomic physics calculations. A selection of these fundamental studies,
applications and diagnostic projects will be described.
RECRUTEMENT ACCES DIRECT
Le département de physique
Fête de la Science 2018 