Thursday, February 14, 2008


I do believe plasma physics has gone astray by the unfortunate use of the term instability to describe how a plasma reacts on itself. I think the term reaction would help to open up people's mindset. A plasma is not a stable thing. It reacts to everything including itself.

Plasma kinking is not an instability, plasma kinking is a reaction.


brent said...

I'm taking a Advanced Thermodynamics course and we've touched upon the issues of modeling molecular systems to determine thermodynamic quantities. One of these is using the Monte Carlo method in the context of statistical mechanics. I realize from searching the web that some studies using the Monte Carlo method have progressed both through Mike Rosing's
and Nicholas Krall's
. Forgive me for those I haven't turned up. I recently put up a weblog posting in an attempt to describe what I know about Polywell. More specifically for this case, I gave thoughts about dynamics simulations and statistical mechanics that have been derived from the class I am in.

baley said...

I think the correct way is instability don't forget that the people that did use that term are engineers. They are talking about a fluid mechanic macroscopic effect very similar to the instabilities seen in turbulent flows.

Furtermore if they were to call it reaction you would confuse it with the nuclear reaction.

M. Simon said...

Instability takes you down the wrong road. It gives you a mind set that there is some naturally stable plasma state. Bad mind set.

As to reaction - we have reaction mass and chemical reactions. We have biological reactions. It is a very useful word.

baley said...

Maybe we engineers are lazy with the names, but the reasons for the name is because it's a term frequently used in fluid dynamics (hence plasma turbulence too). And don't worry Engineers know that it's unstable only too well (after 40+ years of tokamak research!).

BTW do you know of any recent scientific journals that Bussard published (or any of the people continuing his work) regarding the polywell device, the results and so on? I recently searched but with no results.

M. Simon said...

The trouble with "instabilities" is that it posits a stable regime i.e. laminar vs turbulent flow.

In plasma there is no stability, only reaction.

M. Simon said...

As to publications: what there are are listed on the sidebar.

baley said...

Engineers don't like arguing about semantics, that's the name stick with it :P ...

FYI when the plasma gets really kinky then they don't call it instabilities anymore but disruptions and when they are bad disruptive disruptions.

See this book (the science of JET):