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Earl of Plasma wrote: I’m trying my best to understand this process of fusion so I have some Questions.

Welcome to the Focus Fusion Society forums!

Earl of Plasma wrote: “First temperature. PPL are talking about several hundred milj kelvin acheaved in experiments. Other have problems to reach even 100 milj Kelvin. Just with electrodes as it seems? For exemple a Tokamak use current and radio waves just to reach 100 milj degrees. How is that possibly? How do they do?

Size is the key… or lack of it 🙂

LPP (Lawrenceville Plasma Physics) achieved the confinement of ions with energies in excess of 100 keV (100,000 electron volts) which is the equivalent of a temperature of over 1 billion degrees Celsius. They did this in a device called a dense plasma focus… and the plasmoid where this occurred was only a few hundred microns across and lasted only for a few microseconds.

But that was enough to achieve the desired temperatures and confinement times for boron-hydrogen fusion and that’s what matters. Now LPP is working on increasing the density of their plasmoids.

ITER, on the other hand… well, although ITER only needs to reach a temperature of 100 million degrees to fuse its deuterium-tritium fuel its tokamak design has to try to heat a volume of plasma of 840 cubic meters to that temperature for about 300-500 seconds at a time… and that’s proven to be quite a challenge for them.

Earl of Plasma wrote: Magnetic field. PPL are talking about giga Gauss in the magnetic field of the plasma. 1 giga Gauss is about 100 000 Tesla. 100 Tesla is pretty much and is hard to achieve for long time. How is that possibly?

Same way the temperatures are achieved: in a very small space for a very short time.

Rather than trying to fight the natural instabilities of the process the Focus Fusion design takes advantage of them and lets them run their course.

And LPP and Focus Fusion advocates are not the only ones to have noticed that smaller and faster might be a better route to fusion. Indeed, quite a few alternative non-tokamak fusion designs are now under development and are seeking funding.

And yet President Obama’s new budget proposal once again cuts domestic fusion research funding and transfers it to ITER…

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Francisl wrote: zapkitty, thank you for fixing the links.
The link for Ceres should be “http://en.wikipedia.org/wiki/Ceres_(organization)” . The forum software seems to change it to “http://en.wikipedia.org/wiki/Ceres_organization” . The parentheses are getting dropped for some reason, resulting in a bad link.

Yep, I missed that… sorry!

It’s a known expressionengine drawback.

And yet another reason to migrate to another CMS.

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Francisl wrote: The above links aren’t working very well today…

You were linking to en.wiki.org, which doesn’t exist… wiki.org doesn’t have an “en” subdomain.

I fixed your links by changing en.wiki.org to en.wikipedia.org

Edit by zapkitty: well, that fixed one link but ExpressionEngine simply refuses to follow the second link, the one to the Wiki page on the Ceres organition, because EE thinks that a parenthesis in an URL is a security risk… which is yet another reason we’re prepping to migrate to a new CMS.

Our apologies to those inconvenienced.

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Francisl wrote: I would like the ability to post links that don’t break because the forum doesn’t understand some links from other websites.

Can you provide an example or a more detailed description?

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rimmini wrote: I was watching the TED talk on focus fusion and it struck me. What you have here is a thermionic generator with a “virtual” emitter. Maybe I am just showing my ignorance but it seems to me that the opposing jets, being of electrons and protons respectively should set up a “battery”. This battery should have a DC voltage equal to the voltage difference between the two ends and a current proportional to the density of the electron beam.

It is true that in standard DPF units both beams, electron and ion, exit the plasmoid in opposite directions… but in a Focus Fusion generator it’s expected that the election beam will not make it out of the plasmoid.

Instead it should be absorbed by the plasmoid and further heat the plasma, resulting both in an increased fusion event rate and a decidedly lopsided beam emission as the ions make their getaway 🙂

rimmini wrote: Any way just saying hi. Hope to learn a lot more.

Welcome to the Focus Fusion Forums!

[zapkitty]

Here’s a proposal for consideration along with the background
reasoning.

The primary FFS website: News related to Focus Fusion Society efforts,
Focus Fusion news and LPP doings and fusion power news in general. Also
basic fusion info with an emphasis on aneutronic fusion and its benefits
as a power source.

Background: A needed website upgrade. The CMS in the background will be
a current version of one of the popular non-proprietary engines. Which
one depends on FFS current and projected needs. In reality any such CMS
could handle all FFS needs while being more flexible and easier to
maintain, update and upgrade with our resources than the current EE
installation.

Upshot: Ignas life easier. My life easier.

Built into the system will be a potentially community-enhancing option:
Articles by FFS members. I’m thinking this should be for paid members
(isn’t it about time for me to re-up?) Any paid member can author such
articles and any FFS site member can comment on such. I’m thinking of a
bit more formal take on the “diary” concept. Site members will be able
to add comments to the articles just as they interact in the forums now.

Upshot: Functionally not much more different than the way things are
supposed to be now. That’s why paid members are labeled as Administrators
in the current EE setup: they have publishing capabilities among other
things but do not use it and at least in some cases do not fully
understand their options. So the upgrade will improve things a lot in
that aspect because people will be able to more easily understand and
take advantage of the options made available to them.

On the downside will be the minding of content and other editorial
duties. It will be a bit more work… but it’ll be stuff we’d be doing
anyway if more people were active at this time and we’ll have those same
newly active members to help each other out.

And the forums will still be needed. Needed for site members to have a
platform of sorts and needed for news items, questions, comments or
links that are too short for an article. And yes, needed for continuity.

Upshot: An upgraded forum will be easier to maintain and yet add much
more capability than the default EE forum we use now.

Thoughts?

[zapkitty]

Henning wrote: Please be aware, that the discharge time is crucial. The switch has to operate 45 kV / 2.8 MA within 100 µs or better (something of this order). And the capacitors / electric sources have to supply them within that time.

I don’t have the graphs currently, but this is a steep increase in power over time.

Gonna need some hefty wall plugs 🙂

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Breakable wrote: I guess Reddit is my ideal forum. Here is a sample:
http://www.reddit.com/r/fusion/comments/15wtyd/has_net_energy_gain_q_1_ever_been_demonstrated/

… have you tried visiting that link with cookies
disabled?

As for the general concept, that of members rating
what other members post?

It’s alright for trying to stir up interest in posting and
to enhance site traffic, and it can be used to bring
relevant articles to members attention.

But at a cost: it increases the site maintenance work
load substantially and is also subject to abuse. Just a
fact.

There are a variety of ways such an idea could be
implemented depending on how the site is set up to
function. Member-written articles or “diaries” that can
be recommended by other members is another
popular version.

And at this time most any forum post gets attention.
When the main site is updated and cleaned up it
should get more attention as well.

Right now the site and forum serve primarily as a
news forum, secondarily as an interest group forum
and as a de facto knowledge base for aneutronic
fusion and DPF technology… although the “knowledge
base” part is not very well organized.

And it could be helpful to have a general idea as to
how the new LPP site is going to be organized, so the
FFS can refer to them when appropriate.

Would also be nice to have references to other
aneutronic sites but EMC2 is basically a placeholder at
them moment and Tri-Alpha still ain’t saying much on
the net.

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The beryllium is to be recycled into new electrodes.

In fact I can’t think of anything in an FF unit that can’t be reused or recycled.

Component recycling and reusability shows an additional way that the FF unit’s lack of radioactive waste gives it a major advantage over all fission and D-T fusion plants.

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… and a stronger cathode redesign, such as this one mentioned in the July 15 2013 LPP report, might also be more amenable to cooling solutions than the current array of cylinders.

Attached files

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Tulse wrote: I believe the tungsten is just for the current round of tests. The intent is to make the production electrodes out of beryllium, as it is relatively transparent to x-rays and thus won’t heat up as much and absorb energy that would be captured by the “onion” and produce power.

Yep, but the more immediate concern would be the x-rays adding even more heat to an already serious, but solvable, electrode cooling problem.

So using tungsten or any other high-z material for the electrodes in a [em]production[/em] machine would be a recipe for deep-fried fofu.

Tungsten is needed for the intermediate stages of testing, though, as it can take quite a bit more abuse from the researchers as they figure out how to build one of these things 🙂

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ikanreed wrote: PB11 by 2015? Sounds ambitious.

… where can I buy one? 🙂

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Henning wrote: As far I understood Eric, the effect of the axial coil in FF1 is to get the plasma sheath into filaments as early as possible.

That’s what the tungsten “crown” at the base of the anode is meant to do… encourage the start of filamentation in the sheath.

The axial field is meant to impart a small rotational component to the sheath/filaments as they travel down the electrodes so that when the pinch comes the filaments more readily swirl into a vortex rather than clashing together and thus losing energy.

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asymmetric_implosion wrote: The ideas are nearly identical during the radial compression…

But I’m thinking that if the axial spin is applied during the DPF’s rundown phase by, say, a helical configuration of the electrodes instead of, and not as efficiently controlled as, FF’s axial coil (an option that has been considered elsewhere) then all that follows after the rundown, the events during the radial compression that you mention, would all happen in the DPF [em]without[/em] benefit of the initial axial field.

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Francisl wrote:

I’m nowhere near the physicist it would take to even know if Rayleigh-Taylor instabilities even affect FocusFusion. All I know is that both experiments are Z-pinch based. Is there any applicability of this info on FoFu-1?

Please consider two points:
1. This demonstrates that progress and innovation is occurring in the fusion field.
2. LPPx showed the effectiveness of a small axial magnetic field to improve the intensity of a pinch. This is similar.

Well, similar in the concept of small magnetic fields being capable of having a beneficial effect in the midst of far more powerful fields.

But just as a Focus Fusion DPF and a MagLIF device are very different devices, the small fields that each uses and their respective purposes are also very different.

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