FEBAUSA said:
What are the problems for development, continuouly power production and economical, in a nuclear fusion reactor and nuclear fusion power plant ?
FEBAUSA,
In a word - "breakeven".
As of yet, we don't know how to achieve "breakeven" - that is to get as
much energy out of the plasma as we put into make the plasma.
The basic approaches to fusion are "magnetic confinement" and
"inertial confinement".
Magnetic confinement uses machines like "tokamaks" to confine the
plasma with magnetic fields. The problem there is that a magnetically
confined plasma has all sorts of instabilities - and it breaks up before
we can hold it long enough to get back as much energy as we put into it.
Magnetic confinement is chiefly studied at the Princeton Plasma Physics
Laboratory:
http://www.pppl.gov/
The other approach is "inertial confinement" fusion. Here, you don't
even attempt to try to "hold" the plasma. You create a very dense
plasma that burns very fast, and you count on the fact that the inertia
of the mass of the plasma will hold it together long enough to get
useful energy. The confinement time will be very short - but if the
fusion burn is fast enough - you could still get a useful amount of energy.
[ After all, that's how hydrogen bombs work - they don't hold together
very long - but they produce energy so fast that the small confinement
time is long enough ].
The problem with inertial confinement fusion is that we haven't been
able to create a plasma large enough to trap the alpha particles which
you want to do to get "ignition". That is, just as a fire uses the heat from
combustion to keep the fire going - you want to trap the alpha particles
to keep the fusion fire going. Previous experimental machines couldn't
do that - but that is changing.
The principal means of heating and compressing a plasma in inertial
confinement fusion is with lasers - also called "laser fusion". The
principal research centers are at Lawrence Livermore National Lab,
and the Laboratory for Laser Energetics at the University of Rochester.
Lawrence Livermore National Laboratory is building the NIF - the
National Ignition Facility. This 192 beam laser should be powerful
enough to create a plasma large enough to achieve ignition. The NIF
building is finished, as are the first set of lasers. More lasers will be
brought online during the next few years until the entire 192 beam
complement of lasers is finished. See:
National Ignition Facility at Lawrence Livermore National Laboratory:
http://www.llnl.gov/nif/
http://www.llnl.gov/nif/project/index.html
http://www.llnl.gov/nif/project/news_nel1.html
OMEGA laser at the Laboratory for Laser Energetics at University of Rochester:
http://www.lle.rochester.edu/
Another method for inertial confinement is to use large pulsed power
sources to "magnetically implode" plasmas in what is called "Z-pinch
inertial confinement fusion". This research is underway at the
Sandia National Laboratory in Albuquerque, New Mexico:
http://www.sandia.gov/pulsedpower/
http://www.sandia.gov/LabNews/LN09-24-99/fusion_story.html
http://zpinch.sandia.gov/
http://www.sandia.gov/media/z290.htm
http://zpinch.sandia.gov/Z/Images/z.jpg
Hope that's enough to get you started.
Dr. Gregory Greenman
Physicist
