## Thursday, October 09, 2014 ... /////

### Fusion: dynomak, a new compact rival of tokamak

Fusion is the energy of the future, and it always will be. Despite this proverb, many teams are working hard to confine the hot plasma for a sufficient time and allow the fusion to be sufficiently long-lived and economically feasible.

I do follow the fusion research in some moderate detail because I do think that it's the most likely future advance that could make a "qualitative abrupt change" in the methods that we exploit to obtain energy. If you look at the fusion category of TRF blog posts, you will find some texts debunking Andrea Rossi's cold fusion but many more "real experiments" such as NIF with its lasers, the Z-machine, and – obviously – ITER, a French-international version of the tokamak concept.

Yesterday, University of Washington released a press release on their dynomak paradigm.

The picture above shows that it is a nicely compact prototype. I haven't been able to see what the successes have been but they say that it could be cheaper to be built than coal power plants etc.

The design originated from term paper in the classrooms of University of Washington which is pretty cool. In April, Elsevier's journal Fusion Engineering and Design published their
The dynomak: An advanced spheromak reactor concept with imposed-dynamo current drive and next-generation nuclear power technologies
by 10 UW authors including Derek Sutherland and Thomas Jarboe.

The design is known as "spheromak" – it's a word used at least since the late 1970s – or "dynomak" – which is their new name for this particular University of Washington incarnation of the idea. The word "spheromak" has mostly meant that the magnetic field needed to confine the plasma is generated... by currents running through the plasma itself. The abstract of that paper tells you quite a lot what molten salt they propose for first-wall cooling and tons of other technical issues as well as some economic and efficiency estimates.

I wish them a lot of good luck. If electric energy were produced mostly by similar gadgets in the future, I think that it would get cheaper and people would finally start to switch to electric cars and other things that are economically inferior these days.

#### snail feedback (88) :

If the corrosion problem with molten salt (of some sort) thorium reactors can be overcome it could be a nice solution until this still further into the future prospect (it seems to me) might be realized.

Meanwhile, back in the real world, the unmentionable fusion seems to be doing well. Another test, another report, but still the fraudulent method that must be there is elusive:

It's doing well, especially the "Gentlemen" who perpetrate this fraud. It just hasn't generated a single joule of energy.

Yet more fusion fraud. At least Fleischmann and Pons were merely confused. These criminals should be in prison.

Huh, do you mean the dynomak? I can't believe you have these ideas. Why do you think that the Sun is shining? Is it due to lots of blue LED diodes on the surface?

The dynomak research should be given a boost of a billion of dollars and copied at several other places.

OK, fusion is *much* cooler - I shouldn't use this adjective, I guess LOL - and it can't be quite excluded that it will run before the modest thorium-based fission reactors.

Given that energy density is the central concept for assessing the technologies of energy production, there can be no doubt that fusion is the [future advance that could make a "qualitative abrupt change" in the methods that we exploit to obtain energy].

But I’m betting one of physics' more embarrassing lacuna, a thorough characterization of turbulence, will stifle the magnetic confinement approaches. Given the intrinsic non-linearities of gas dynamics, plasma’s at those temperatures are riddled by turbulent instabilities giving rise to most daunting of engineering challenges.

I’ll bet on laser inertial confinement winning the race.

Thanks for this first remotely on-topic and not staggeringly insane comment, Tom. ;-)

I think that the masks are automatically deployed whenever there is a sudden depressurization, as would surely happen if the aircraft's fuselage was ruptured at high altitude.

Excellent you said it this explicitly. How quickly do you think the folks would die after the hit by a BUK missile?

Could the oxygen mask end on his neck by coincidence?

Just an opinion for sure, but I did do a fair amount of CFD back in the day.

You are in for a big surprise and a lot of self-doubt.

Cool, you should have said.

What seems sort of strange is that you make it sound that the MHD instability is a "new threat" of a sort that makes this spheromak harder.

It makes fusion harder but spheromaks are already an *answer* to the pre-existing MHD instability problem - that's why the MHD instability appears in the title of the first famous spheromak article.

Thanks, Lubos, I’ll read these links later in the day. No doubt, MHD instability was the issue from day one in fusion research so my writing is (not-unusually) flawed to have conveyed a “new threat” tone.

My intuition is simply that the engineering responses to refine the confinement as instabilities arise will never be fast enough to keep up with the turbulence. I’m guessing we’re talking nanosecond time scales in a domain where only statistical fits are available. Now, if somebody gives the energy density in a turbulent flow in some kind of closed form, then maybe the engineers can come up with the necessary super-fast control circuits.

Maybe if he was scared and fast enough

Lots of things could happen in such a chaotic situation. I have no idea what the probabilities might be, and I suspect no one else does, either.

There is a reasonably informed discussion of this incident here: http://www.pprune.org/rumours-news/543733-mh17-down-near-donetsk.html
The fragmentation warhead of a BUK missile would create multiple high speed chunks peppering the fuselage. The airplane would be torn apart by aerodynamic stresses, but the pieces would still be plenty large enough to hold passengers and very 'lucky' individuals might survive decompression long enough to grab an oxygen mask. It is very unlikely that a mask would slip around a passengers neck from air turbulence.

You are too pessimistic, Lubos. Reason eventually wins out over ignorance. You can safely ignore the stupidity. And should, I think.

The masks deploy automatically when the pressure drops, or can be triggered from the flight deck:

I think it is more likely that the plane broke up (SAMs generally detonate NEAR the target and blast shrapnel through it, not exploding inside the plane like a movie) and one of the passengers remained conscious long enough to try to get the mask on. That it was only partially on shows how quickly he blacked out from the altitude.

I am sure you are right about this happy end, Gene - but I won't be around to see it.

Thanks, and concerning the last point, I think that what I wrote was nonsense because the mask was "attached" around the neck which requires one to "click" the pieces into each other - impossible to happen randomly.

Could please the people who believe that fusion is a non-existent process and those who believe that fusion may be "cold" stop posting their idiotic "contributions" to this website?

After several hours I had to cool down after those comments that made me so upset, I am still very upset so I decided to ban everyone who is this stupid and posts something like that again, whether or not he has been posting here for years.

Maybe world governments can get together and make a deal that if physicists focus on building a usable fusion reactor then the governments will pay for a great big particle accelerator.

Great. The fields are correlated although true particle physics is done for completely different motivations than fusion physics. Fusion research is applied, particle physics is pure science. Also, fusion research is a relatively low-energy (I mean QCD scale, not cold-like low haha) physics while the cutting edge is at much higher energies.

But even if one ignores the differences, I don't think that the correlation is any helpful because, as the structure of the comments before I started to impose the ban shows, the hostility against (hot!) fusion research is exactly as intense as the hostility towards pure particle physics. Most people, at least most of the loud active trolls on the Internet, are complete science---illiterate imbeciles!

I want my Mr. Fusion

wow! I think the abstract caused set my pc on fire, and I have no insurance on it. Are they even using real words?

BUK missile or fighter jet, I doubt that people would immediately become unconscious after a plane's hull is breached. Rapid decompression obviously leads to the breathable air being sucked out of the aircraft, but even if the people couldn't breath anymore, they still would have had enough oxygen in their bloodstreams to remain conscious for a minute or so. Of course, there's also the sudden extreme temperature difference after rapid decompression, but is that enough to knock someone out? Hypothetically speaking, if I leave my warm room and walk into a meat freezer, I remain conscious too, so I doubt it.

Sadly, I think only the people that were directly hit by a bullet or fragment were killed. All the others lived much longer.

In fact there are even scientists amateurs who get to do authentic fusion at home. Through a design called fusor. (Without reaching energetic gain, obviously)

http://en.wikipedia.org/wiki/Fusor
http://www.fusor.net/

A fission reactor's energy is mostly recoil of nascent fission fragments - thermal output - plus a couple or three average 0.8 MeV neutrons to chain react. D + T belches He ( 3.5 MeV ) + neutron (14.1 MeV ) 80% of fusion reactor energy is in the neutron. Go ahead, recover the energy. You then have an ocean of thermal neutrons activating everything, and decaying into beta-rays outside the reactor.

A thick blanket of molten lithium used for breeding fuel and heat exchange is cute. Look up pumping liquid lithium.

Hasn't generated a single joule? Did you read the report? In the summary it clearly says the Rossi device generated 1.5MWh over 32 days. I'll let you convert that to joules.

Which part of the report do you suspect is bad? Dishonest reviewers? Hidden wires? Bad calorimetry?

The Russians have done a test shooting at a plane, and then they show the impact. Quite amazing the comparisons (from around 7:30, at 8:24 you see the comparison with the MH17 in one picture). They also mention the wing:

Also the straight patterns at 7:55 are similar to the ones you also see at MH17:

https://pbs.twimg.com/media/BxBNE99IAAEYZAa.jpg:large

Also interesting is this interview where 2 people mention a 2nd airplane:

See how Paris Match tried to hide this fact by twisting the translation of the text, and cutting short fragments about the other airplane (see also comments below). The BBC had also such a report, but that one disappeared for some unknown reason from their website:

Sorry guys, I forgot to include the Russian video:

When comes the time - when you will need to eat those words ... What will you do (just saying if) ? ... You are taking a monumentally strong position and are very well may be significantly deceiving your poor readers .. so I think when proven wrong, you should do something monumental ... I have a suggestion ... I would like you to carefully place your head... safely .. but firmly ... where it belongs ... If you need any help don't hesitate to call :)

OMG, that's hilarious, are they really trying to say that a few gun rounds (with nice round entry points) are at all similar to a massive shrapnel type cloud observed on the wreckage?

When it comes to nuclear power, either fission of fusion, I do not understand why the left is against both. Inexpensive energy would lift all boats, spending money on fusion or fission power make a whole lot more sense than studying climate change, Oh I forgot the educated idiots need to do something, and nuclear physics is way beyond them on any level. To bad the are hogging most of the money! Yet that not surprising the only thing dumber than a AGW climate scientist is the media and the politician whom are financing them.

Is it some shaving or why is it male? ;-)

The right figure is clearly 0.0MWh over any number of days, I didn't like that it's wrong from the first page to the last one and, most seriously, that this whole industry is complete fraud that continued without any punishment of the culprits for many years. I allowed you to post this one but banned you immediately afterwards.

Gene. I wonder why you are at even older age than I still optimistic to think that reason will win? There seems to me overwhelming stupidity and monumental ignorance at every turn. I am somewhat less sure I am joking each time I say that Idiocracy is a documentary.

Could not agree more!

Fer, I would just add that fusors still make the normal, hot fusion - the temperature has to reach those 45 million kelvins which is achieved by acceleration with 4 kilovolts. Nothing "cold" about fusors.

Savage, I banned you. This is *not* a place for savages to legitimize their utter delusions and fraud.

I do harbor a hope (not sure how well justified) that the type of fission technology that would utilize thorium also would be able to make use of and use up much of the radioactive waste that the currently entrenched fission technology keeps causing a cumbersome accumulation and storage requirement of.

Exactly. Even if one "needed" to switch to other sources, one would have to achieve a breakthrough by studying particular things that the conservatives often fund and leftwingers criticize - such as nuclear technologies. Or some other high-energy physics etc.

(Just to be sure, in Czechia, there is a pro-nuclear consensus across the political spectrum, so the left-wing opposition is a matter of local group think. After all, our first nuclear power plants were built during communism.)

I found this Russian video much more interesting than the other ones.

The first detail that struck me was the near-intersection of the MH17 flight with a very similar plane that had Putin on the board. That's pretty amazing if true.

I am no expert but the first thing I would say when I see these holes *is* that they are round gun rounds.

The idea that the plane was shot down by cannon fire from the Su-27 does not seem to make a great deal of sense to me. If the Ukes wanted to perpetrate a false flag event why would they use a method involving a plane that did not really have the height capability unless pushed to the limit and furthermore have the possibility of leaving evidence on the ground in the form of regular cannon shot holes in the plane that could be conclusively identified if required.

So it makes sense that you would just use a BUK missile since that can easily be blamed on the warmongering separatist incompetents and their Russian patrons. Looking at the available pictures it certainly appears that the plane was hit by a cloud of shrapnel from the alleged BUK although there are oddities such as the appearance of holes going both ways and the hit on the wingtip which appears to come from another direction.

In my opinion the Su-27 was more likely using the Malaysian plane as radar cover for a bombing run which was known to be occurring. Possibly MH17 was diverted over the warzone for this purpose. Or Mh17 was shot down by a BUK fired by the Ukes and the Su-27 was there for observation purposes. Or the presence of the Su-27 is illusory at present.

Those particular Germans are loonies. The variety of sizes of holes, their two-dimensional spread, and their sheer number, are all inconsistent with fighters' guns.

but how do you really feel,lubos?

Lubos, I followed your link and read a few abstracts and I am somewhat surprised on the ubiquity of the MHD model. The conditions for ideal MHD to hold, principally, I guess, overall charge neutrality and infinite conductivity, I would think break down in fully turbulent regions of flows at such temperatures. So I expected to see full-up electro-magneto gas dynamics equations, which introduces a wave family much more complex than Alfven waves alone. But, then, CFD was at the beginning of my career, so I’m guessing I am now a fossil.

(OT but what a nice arrow-of-time post you put up today, I doubt it can be put any simpler.)

Hi, my understanding is that turbulence is ultimately lethal for the spheromak and other gadgets but the very point of this construction is that it reduces or delay turbulence (isn't it what the "MHD stability" helps to achieve?) so that equations neglecting it may be used for a very long time.

yes, could be true. For me it is all interesting information (not only the Russian video), because combined it all points towards another airplane, and not to a BUK missile.
There is of course much more, such as the flight data and black box that has not been released, the secrecy of the investigation committee in which Kiev takes part (very weird), etc, etc... All together makes it for me 95% sure it was Kiev.

Dear Luboš,

I'm not much good at physics but I feel we share a lot in common. I'd say was down to your general attitude.

I do so feel at home here. :)

Well, just look at the images, and you can see that 'the few gun rounds' of the Russians show more holes than those on the MH17. But you also forgot another very interesting detail. Away from the cockpit there is no snaprel on the MH17 at all.
http://cdn4.independent.ie/incoming/article30460508.ece/39d99/ALTERNATES/h342/ISIS-AIRPLANE_322.jpg

LOL, you probably are, but I am often among those who are stunned by some of your comments.

Loves and kisses to you too. XXX

:)

How do you explain that you see the same inconsistencies in the Russian 30mm gun shot results? (8:24 Russian video you see the comparison with the MH17 in one picture). You claim here that that is impossible...

The planes move so everytime the angle of impact differs, making different holes. So they are not at all inconsistent. The patterns showing holes in a row together with the wing and the absence of snaprel in other parts of the plane make a BUK scenario almost impossible.

Maybe you have put your finger on the main problem - all these gadgets assume they can reach the fusion point without turbulence occurring, but it seems to have a nasty habit of always cropping up. The inertial confinement case is interesting in this light because even with the 192 lasers that Livermore uses to generate a field on the pinhead-sized target’s surface it still deviates enough from spherical symmetry to induce turbulence.

Yes, the intelligent support does extend across left/right lines. There is a documentary called Pandora's Promise on Netflix featuring Stewart Brand (The Whole Earth Catalog) and
others who would be characterized as left wing. They have been convinced that nuclear is the better and safer option for power.
BTW has Ron Maimon ever explained to you why he believes in cold fusion? Schwinger did also, and I don't accept that he was senile in any way, but I also am not arguing with you that cold fusion is correct...just wondering why two people who are obviously intelligent seem fooled. They must have some rationale to explain.

lol--- the sun obviously doesn't work using leds---it uses plasma screen technology :)

Ron has always miraculously run out of time when there was an indication that he may want to explain his belief in cold fusion. ;-)

Of course, fusor is hot fusion. (I wrote 'authentic hot fusion at home'). Although you were talking mostly about cold fusion scams in previous comment, I was thinking rather the other crank-group: fusion-impossible. So I remembered the fusor: if someone had doubts about the reality of fusion in stars,etc. always would be possible to test it for themselves at home, following the steps in the second link (With enough time and brain)

--------------------------------
OffTopic/OnTopic always:

In chrome, the right column of this blog, from "trf global facebook like button", is vibrating wildly when zoom is 110, 150, 175, 250 or 500 %.
(but not in 100,125,200, 300, 400%)
Maybe a bug in a components in that column. Perhaps depends of pixels of each monitor, I haven't checked in other computer.

I used to read with 110% and it was uncomfortable when I reached this depth. I even thought it might be a dirty trick to force click that like-button :) (because vibrato start at that point) Then I realized that it was due to zoom.

I find it funny how someone that believes in hidden dimensions and believes that a cat can be dead and alive at the same time would have such a visceral reaction to the possibility that there might possibly be something going on in this world that cannot be explained!

Hi, before I blacklisted you, I approved your comment to sort of show to others more representatively how many stunning aggressive imbeciles are being attracted to my blog.

There is nothing going on in nuclear physics - or any phenomena up to 100 GeV, with a possible exception of some hypothetical very weakly interacting particles to be found - that hasn't been understood. And there is nothing at all in the Universe at all that can't be understood at all.

The fact that cats and all other objects in the world are generally found in a complex superposition of states has been known for 89 years and no one except for hopeless mental cripples has any doubt about it. And the evidence backing the existence of extra dimensions is less waterproof but still very strong.

Hi Lubos,

I think it is because he discovered there was something wrong with his theory.

He takes some "results" from the "research" as reliable and thought his theory could explain the results, but apparently he is no longer sure.

You can read his statement here http://en.wikiversity.org/wiki/Talk:Cold_fusion/Theory/Ron_Maimon_Theory#Conclusions

, at the bottom of the page if you are interested (maybe you aren't ;-).

I am only posting this, as it shows he is honest and does admit mistake.

Hope you are well, and this little post did not annoy you.

Yes. Fusion is very problematic.

Fission energy product fragments are heavy and slow. Not fusion. Fast neutrons.

Uncle Al, how many mega-curries of tritium will there be in a fusion reactor? How easy is it to contain hydrogen?

Looking at a single reaction fission produces more energy but if you instead look at energy by unit of mass fusion produces more.

There is a method for dealing with thermal neutrons: control rods. These are used every day in existing fission reactors to absorb excess neutrons in order to avoid a meltdown. Of course, for a fusion reactor you might need to change the shape and form of those rods and instead use some kind of shell but the technique would still work. As a fusion reactor is not dependent on free moving neutrons to produce energy there is no need to regulate as you do in fission reactions - you can just capture all of them instead.

This is why a fission reactor typically uses electromagnets to control the rods. Should the power go out the rods will drop into place and capture enough neutrons to stop the chain reaction. This kind of safety is not neccessary in a fusion reactor as it would stop working as soon as the power goes out.

A fusion reactor is like a fire you have to feed in order to keep it going. A fission reactor is like a bomb you constantly need to control for it not to "blow" up.

physics junkie,

Mr Fusion won't ever be.

But Philo Farnsworth came *only* several orders-of-magnitude short of that... 1 exp minus 10,000 energy multiplication. You can built a desk-top fusion device. http://en.wikipedia.org/wiki/Fusor

Lubos,

Mr Fusion was a stupid movie, time travel. No logical arrow of time.

It's an extremely long conversation and I am not able to locate a paragraph you want me to read. So sorry.

Otherwise good to hear if it's true. Still interested in his text why he believed what he did and what was wrong.

Hi, should have been more specific then, I apologize and will give you quotes instead.

(He still does not question the experimenters though,)

From the bottom of http://en.wikiversity.org/wiki/Talk:Cold_fusion/Theory/Ron_Maimon_Theory#Conclusions

"Hagelstein is completely right. I removed the claims that this theory matches the experimental data."

From the bottom of http://en.wikiversity.org/wiki/Cold_fusion/Theory/Ron_Maimon_Theory (where his theory also is described in a little detail, not much math though)

"This theory has no ad-hoc theoretical assumptions, and it is consistent with some of the data, but it predicts too many incoherent neutrons from the fast charged particles, and is excluded by Hagelstein's analysis of the limits on energy of the He nuclei produced."

And the lower picture you posted also disproves the claim. The caption to Figure 12 is totally the wrong way around - the heater wires have to be the bright bands in the central 'reactor', whether there is a central reaction or not (because they would be heated by the central reaction and they add heat of there own). As the glow in the 'reactor' is so similar to the glow of the outer rods, and the region between the heater wires is so dark, there is nothing going on here. This would have been seen if they did the calibration run under the same conditions as the live run, but (yet again!) they didn't.

Another fusion advance: the Z-machine at Sandia, see

http://news.sciencemag.org/physics/2014/10/z-machine-makes-progress-toward-nuclear-fusion

claims new progress. They produce 100 times more reactions than before, still 10,000 times less than needed to achieve a positive energy budget, and they saw the first neutrons, a sign of the "secondary" deuterium-tritium reaction, indicating that the fuel was really confined for quite some time.

I see---but I do have a copy of Ron's proof:
https://www.flickr.com/photos/jpallan/4633000725/

LOL, sometimes I would like to know whether those guys were just fooled by some cheap tricks or whether they're bought. If it is the former, it is pretty embarrassing for them.

Lubos
Cold fusion guys also watch Ancient Aliens as though it is a documentary. Also believe we never landed on the moon too.....LOL

Just a thought wouldn't it be better to use a larger containment vessel with the same amount of fuel they use now. The larger containment would allow the turbulence more room and may start a convection zones similar to what we see in stars. Stars use gravity to contain the reaction but we don't have that luxury here on Earth. My thought is that maybe setting up convection may contain the turbulence. My two cents.

They may be on the opposite, "Yes we can", side, Jim! The CIA has artificially produced the moon and planted it on the orbit in order for the people to confuse it with the Sun.

Good questions but it's too complicated for me. A lower density could perhaps reduce the problems with turbulence but it also reduces the pressure and a high pressure is needed for the reaction to burn well etc.

In the Sun, the temperature and the pressure are a bit lower than in the usual fusion devices, real or proposed ones, and the reaction is much slower (per cubic meter). But the Sun's gravity can actually hold the gas for billions of years - while tokamaks and dynomaks are unlikely to ever be this patient. So one needs to rely on a faster reaction and for that, it is better to have a higher temperature than in the Sun.

I was thinking keeping the density the same with a stronger magnetic container thus would allow the magnetic container more volume to create convection and contain the turbulence. Yes, speeding up the reaction is needed. Not making a comparision to the stars just stating how they contain but the physics remains true for both high temps and or pressure.

Lubos,

Something for nothing fusion is not real, as you say.

But cold, desk top fusion is real. EGG nuke bomb 'triggers' (neutron sources) throw tritium at deuterium, cause fusion, and throw off big bad 14mev neutrons. Cold.

Energy multiplication is many exponents to the wrong side of unity for 'free lunches', but it *is* cold, desktop, fusion.

There can be no cold fusion. The obstacle is Coulomb - electrostatic - repulsion between the nuclei, any nuclei, and deuterium and tritium are no different. Neutrons are electrically neutral so they don't affect the electrostatic repulsion at all. They can't help.

To overcome (most of) the Coulomb barrier to make the probabilities of the nuclei fusion significantly nonzero, one needs a huge kinetic energy of them which is equivalent to millions (or tens or hundreds of millions) of degrees in temperature. If the bulk of the fuel isn't at this temperature, it can't fuse.

My apologies Lubos. Had I read your critique first I would not have taken the report seriously.

I have decided to seek professional psychiatric help tomorrow in the hope of obtaining a lobotomy for my sins or perhaps some more strong hormone therapy on top of the drugs I am already taking.

However your comment on the apparent coincidental complete conversion of the isotopes as shown in the fraudulent document, if I may suggest, depends on the theory for example that the alleged heat production must be associated with the said isotope conversion.

Given the impossible nature of the alleged nuclear reaction perhaps the isotopes converted quickly at the beginning in order to facilitate the heat production. After no radiation is given off so there is no need to assume any form of conventional reaction.

We will have to wait until the next fraudulent report to see if this issue is resolved further, or perhaps one or more of the wretched experimenters will finally confess to the hoax.

It does seem fairly plausible that containment volume could help, especially if it where on the scale of power plant size.

Pondering on this stuff for the last few days, especially with the news from Sandia, I guess my thinking comes back to control methods. Turbulence is so ubiquitous that it is always going to arise as temperatures reach the fusion point no matter what the geometry is. So my guess is some manner of very fast control techniques will be needed. Reactive controls for the optical path through a turbulent flow are fairly well developed, so maybe something similar could be used for inertial confinement. The Sandia approach, a mix of inertial and magnetic confinement, might be best for this as control circuits linked to the magnet fields might be able to modulate the turbulence from the inertial crunch.

One thing for sure, fusion energy is the toughest engineering problem mankind has yet seriously faced. It’s pretty likely that a good number of decades will pass before it comes on line.

What are your Thoughts on the Focus Fusion Project at
the Lawrenceville Plasma Physics in Middlesex New Jersey? Does it have potential
to work in the near future, if at all?

Actually, they have a very neat solution to this by proposing a (molten) lithium fluoride salt(FLiBe) for the task, which is much nicer than liquid lithium. It has been proposed for use in "regular" Gen-IV nuclear reactors as a combined moderator/coolant as well, since it has a similar heat capacity to water and is an excellent moderator.

It's a very good competitor to water for transporting(and/or storing) heat even in a regular nuclear, coal or solar thermal power plant. The fact that it can double as the lithium blanket in a fusion reactor is a very nice surprise.

Dear Jim,

Making things bigger is exactly what ITER is doing. By making things larger, the time scales involved in the fluid equation become larger, so containment times become larger and things become easier.

The thing is, big means expensive. Expensive means useless when fusion has to compete with other power sources. ITER and future evolutions of it are already kind of too big and expensive, and ideally you would want to have a design which is smaller, not bigger, if it were possible.

Lubos,

Use electric field to accelerate tritium ions, aim them at deuterium, (14mev neutrons occur), and you have the neutron source 'trigger' of a fission device. Very special gadgets. They 'insert reactivity' at the most advantageous time in the assembly.

They are "cold" in my use of the word; the initiation kinetic energy is electrical not thermal. The device sits on a desktop, it is room temperature, it causes some small amount of fusion, and it is still room temperature on the desk top.

I know that my use of "cold" is incorrect by your correct definition of temperature.

But on the other hand: Tritium, in the center of a fission mass or "pit", boosts the yield of a fission device. That's a fact. The (average) temperature and pressure of the tritium at the center of the assembled critical mass is never high enough to overcome the Coulomb barrier. Yet the fusion (some) occurs. How does that happen?