p-B11 Fast Ignition Scheme Using PW, ps-scale Laser Pulses

Point out news stories, on the net or in mainstream media, related to polywell fusion.

Moderators: tonybarry, MSimon

[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable
TheRadicalModerate
Posts: 145
Joined: Thu Oct 04, 2007 4:19 pm
Location: Austin, TX
Contact:

p-B11 Fast Ignition Scheme Using PW, ps-scale Laser Pulses

Postby TheRadicalModerate » Sat Nov 21, 2015 2:30 am

Here's a group that's claiming they can get ponderomotive acceleration of blocks of plasma in a magnetized target:

http://docs.google.com/viewer?url=http% ... .02465.pdf

Seems like a long shot to me, but it's kinda interesting. I think this is old (70's and 80's) theoretical work from Hora that's been revived with better laser technology. Over my head, frankly. Any opinions?

Skipjack
Posts: 6051
Joined: Sun Sep 28, 2008 2:29 pm
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Re: p-B11 Fast Ignition Scheme Using PW, ps-scale Laser Pulses

Postby Skipjack » Sat Nov 21, 2015 3:30 am

Seems like another variation of the giant NIF. PB11 would make more sense with something like that than DT I suppose, but I am still skeptical of the concept.

mvanwink5
Posts: 1809
Joined: Wed Jul 01, 2009 5:07 am
Location: N.C. Mountains
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Re: p-B11 Fast Ignition Scheme Using PW, ps-scale Laser Pulses

Postby mvanwink5 » Sat Nov 21, 2015 9:19 am

This ain't NIF.

This is not thermal compression of the pellet, but electromagnetic compression induced using two picosecond lasers; and the claimed gain is enormous.

A coil is used to generate the cylindrical kiloTesla field via laser 1 on figure 2 and that coil looks expendable. So each shot from what I am gathering will involve a PB11 pellet and sacrificial coil.

No costs associated with the pellet and coil are given, but there is one per second expended in this scheme. Still, without showing operating costs, the claim is a net $300 million for grid power per year. And further, no capital costs are shown. However, it would seem the capital costs would involve two PS lasers and the alpha collection grid.

There is no 'first wall' problem.

It seems the physics of their scheme is understood theoretically and has experimental backing. Are they asking for money yet?
Near term, cheap, dark horse fusion hits the air waves, GF - TED, LM - Announcement. The race is on.

TheRadicalModerate
Posts: 145
Joined: Thu Oct 04, 2007 4:19 pm
Location: Austin, TX
Contact:

Re: p-B11 Fast Ignition Scheme Using PW, ps-scale Laser Pulses

Postby TheRadicalModerate » Sat Nov 21, 2015 10:26 am


mvanwink5
Posts: 1809
Joined: Wed Jul 01, 2009 5:07 am
Location: N.C. Mountains
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Re: p-B11 Fast Ignition Scheme Using PW, ps-scale Laser Pulses

Postby mvanwink5 » Sat Nov 21, 2015 11:11 am

I would expect that the entire event takes place so fast that there is no possibility for the coil to contaminate the pellet.
Near term, cheap, dark horse fusion hits the air waves, GF - TED, LM - Announcement. The race is on.

Skipjack
Posts: 6051
Joined: Sun Sep 28, 2008 2:29 pm
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Re: p-B11 Fast Ignition Scheme Using PW, ps-scale Laser Pulses

Postby Skipjack » Mon Nov 23, 2015 2:15 am


mvanwink5
Posts: 1809
Joined: Wed Jul 01, 2009 5:07 am
Location: N.C. Mountains
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Re: p-B11 Fast Ignition Scheme Using PW, ps-scale Laser Pulses

Postby mvanwink5 » Mon Nov 23, 2015 9:40 am

That is just being argumentative, like saying a mouse and an elephant are both mammals. And everyone is skeptical. Come on. :roll:
Near term, cheap, dark horse fusion hits the air waves, GF - TED, LM - Announcement. The race is on.

djolds1
Posts: 1296
Joined: Fri Jul 13, 2007 8:03 am
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Re: p-B11 Fast Ignition Scheme Using PW, ps-scale Laser Pulses

Postby djolds1 » Wed Nov 25, 2015 4:58 am

Vae Victis

TheRadicalModerate
Posts: 145
Joined: Thu Oct 04, 2007 4:19 pm
Location: Austin, TX
Contact:

Re: p-B11 Fast Ignition Scheme Using PW, ps-scale Laser Pulses

Postby TheRadicalModerate » Thu Nov 26, 2015 8:00 pm


RERT
Posts: 121
Joined: Mon Jun 02, 2014 9:10 pm
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Re: p-B11 Fast Ignition Scheme Using PW, ps-scale Laser Pulses

Postby RERT » Thu Nov 26, 2015 10:39 pm

I'm quite surprised that there has been no comment on one thing which caught my eye in the paper: they talk of an 'avalanche' reaction with energetic alphas provoking further reactions.

Isn't that a chain reaction? Is the gain so high because they have managed to provoke a small (ok very small!) explosion, and is that of any significance?

R.

D Tibbets
Posts: 2775
Joined: Thu Jun 26, 2008 6:52 am
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Re: p-B11 Fast Ignition Scheme Using PW, ps-scale Laser Pulses

Postby D Tibbets » Fri Nov 27, 2015 4:14 pm

I don't believe it is a chain reaction like a supercritical fision reactor. The alphas from P-B11 fusion are hot and in the dense inertially confined plasma they heat the plasma sufficiently so that the fuel does not require continuous heating from outside. This is the typical ignition process envisioned for fusion reactors where the plasma is dense enough and contained long enough for the hot alphas to thermalize (heat) with the cooler fuel plasma. The alphas don not contribute to any further fusions themselfs. This is a qualified statement as alphas can fuse with each other. This is the triple alpha process in stars. But there are constraints on this process such that I do not think it will occur significantly in typical man made reactors.

Note that in the Polywell, the hot alphas do not hang around long enough to significantly heat the plasma. The alpha containment time is not long enough at the expected densities in a Polywell. They escape through the cusps. I have wondered though, if there is sufficient confluence (focus) of fuel ions in the center, the density in this small volume might be enough for some alpha heating, especially if one of the alphas produced is much lower energy than the other two alphas in the fusion chain. There is some information that one of the alphas may be close to or less than one MeV, and it's thermalization time will be faster than ~ 4 MeV alphas by a factor of ~ 16.

Dan Tibbets
To error is human... and I'm very human.


[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Return to “News”

Who is online

Users browsing this forum: No registered users and 3 guests