Focus Fusion news story

MSimon · Post by **MSimon** » Mon May 07, 2012 2:06 pm

Joseph Chikva wrote:
ladajo wrote:I have to wonder what DMV looks like in the former Soviet Union...
What is "DMV"?

DMV - Department Of Motor Vehicles.

Where you get tested and get papers saying you are qualified to operate a motor vehicle.

MSimon · Post by **MSimon** » Mon May 07, 2012 2:10 pm

ladajo wrote:Thanks, I'll think about this.

93413 is correct. But I don't have a phD to back it up. Or even a degree in anything.

Ivy Matt · Post by **Ivy Matt** » Mon May 07, 2012 2:14 pm

MSimon wrote:
Mike_P wrote:I have been reviewing the RT video piece
I have been out of the loop for a while what is the RT video?

RT, the news agency formerly known as Russia Today:

http://www.youtube.com/watch?v=49p0cZEisTA

http://rt.com/usa/news/plasma-fusion-en ... clear-080/

MSimon · Post by **MSimon** » Mon May 07, 2012 4:03 pm

Ivy Matt wrote:
MSimon wrote:
Mike_P wrote:I have been reviewing the RT video piece
I have been out of the loop for a while what is the RT video?
RT, the news agency formerly known as Russia Today:

http://www.youtube.com/watch?v=49p0cZEisTA

http://rt.com/usa/news/plasma-fusion-en ... clear-080/

Thanks!

KitemanSA · Post by **KitemanSA** » Mon May 07, 2012 5:58 pm

ladajo wrote:
93143 wrote:
ladajo wrote:"thermalising" is flattening the distribution curve
Not strictly accurate. It's possible to specify a distribution function that most people would agree is "flatter" than a Maxwell-Boltzmann distribution; in such a case, the thermalization process would steepen the curve.
Thanks, I'll think about this.

Indeed, this seems to be the process that leads to "annealing". The tangential energy distribution of the ions at the well edge is broader (flatter) than MB and the ions bunch up toward a tighter distribution, thus they are "colder" (dethermalized, re-thermalized?) when they next fall into the well.

Mike_P · Post by **Mike_P** » Mon May 07, 2012 7:08 pm

Going back to earlier comments about POPs...

Would the point of oscillating the field strength be to change the geometry of the well such that colder ions might get a boost/bounce off the moving well wall?

93143 · Post by **93143** » Mon May 07, 2012 8:41 pm

KitemanSA wrote:
ladajo wrote:
93143 wrote: Not strictly accurate. It's possible to specify a distribution function that most people would agree is "flatter" than a Maxwell-Boltzmann distribution; in such a case, the thermalization process would steepen the curve.
Thanks, I'll think about this.
Indeed, this seems to be the process that leads to "annealing". The tangential energy distribution of the ions at the well edge is broader (flatter) than MB and the ions bunch up toward a tighter distribution, thus they are "colder" (dethermalized, re-thermalized?) when they next fall into the well.

Maybe. I'd be careful about this - remember that travelling up a potential well translates velocity-space scatter into spatio-temporal scatter (slower ions can't travel as far up it, faster ones reach the top earlier and with significant energy), which may then be compensated for by collisions and/or wave damping, etc....

ladajo · Post by **ladajo** » Mon May 07, 2012 11:51 pm

Annealing...

KitemanSA · Post by **KitemanSA** » Tue May 08, 2012 12:18 am

93143 wrote: Maybe. I'd be careful about this - remember that travelling up a potential well translates velocity-space scatter into spatio-temporal scatter (slower ions can't travel as far up it, faster ones reach the top earlier and with significant energy), which may then be compensated for by collisions and/or wave damping, etc....

But also remember that the collisional x-section is inversely related to CoM velocity. As two ions with different velocities travel "up the well", their relative velocity (CoM velocity) is quite small so the x-section is large. If they aren't DIRECTLY in line, they will tend to normalize the radial velocity while spreading the tangential. Thus, they should reach the top with a more uniform RADIAL velocity. They then slow down (the well you know) and then the CoM velocity is almost all tangential. This will tend to "thermalize" into a tighter distribution, no?

Joseph Chikva · Post by **Joseph Chikva** » Tue May 08, 2012 3:30 am

KitemanSA wrote:This will tend to "thermalize" into a tighter distribution, no?

If you when saying "a tighter distribution" mean "lower temperature" and ,so, "lower internal energy" - then, no.

First Law of Thermodynamics:
The total amount of energy and matter in the system remains constant, merely changing from one form to another.

So, for lowering of temperature you need not a "closed system" but the system dissipating energy into environment in some form. Any internal interaction e.g. collisions will not help for claimed by you purpose (lowering of temperature).
Look at "annealing" not as on the mechanism of decrease of temperature but only as on the certain averaging mechanism – “relaxation”.

ladajo · Post by **ladajo** » Tue May 08, 2012 1:25 pm

As I understand, and posted even the reference, annealling is a combination of effects that occur as particles approach, enter, and then depart from the "turn-around" region. This combined effect, in turn causes particle thermal distribution to resist flattening in the aggregate. In simple terms, counter-thermalisation.

KitemanSA · Post by **KitemanSA** » Tue May 08, 2012 3:47 pm

ladajo wrote:As I understand, and posted even the reference, annealling is a combination of effects that occur as particles approach, enter, and then depart from the "turn-around" region. This combined effect, in turn causes particle thermal distribution to resist flattening in the aggregate. In simple terms, counter-thermalisation.

Yup, in essense. Thermalization in the low k.e. region tightens the broadened distribution that was initiated by thermalization in the HIGH k.e. region; thermalization, counter-thermalization..

Joseph Chikva · Post by **Joseph Chikva** » Wed May 09, 2012 2:15 am

KitemanSA wrote:thermalization, counter-thermalization..

There is one Kazakh fairy tail in which the man is dressed in a coat full of holes. And on a question "not a cold?" answers that the cold enters into the one hole and leaves from another. So, cold, counter-cold.

hanelyp · Post by **hanelyp** » Thu May 10, 2012 1:51 am

Someone is, as usual, having a problem with comprehension.

Thermalization at low average energy (where collision cross section happens to be larger) is countering thermalization at high average energy. The ions are cycling between regions of high and low kinetic energy. One more effect where the electric potential well is vital to the polywell.

Joseph Chikva · Post by **Joseph Chikva** » Thu May 10, 2012 3:29 am

hanelyp wrote:Someone is, as usual, having a problem with comprehension.

Thermalization at low average energy (where collision cross section happens to be larger) is countering thermalization at high average energy. The ions are cycling between regions of high and low kinetic energy. One more effect where the electric potential well is vital to the polywell.

I like "as usual"

Countering to more thermalization? Some share to thermalization from low cross section collisions but high coherent component and some share from high cross section collisions but low coherent component. Not countering but adding. And due to intense mass transfer uniform temperature in all space occupied by plasma.
And this all in case if: "The ions are cycling between regions of high and low kinetic energy" – the desired Polywell principle works. As more likely that "better heating by external injection" means conventional heating and not oscillations of ions around negative well located in center.