Monday, March 15, 2010


Mr. Inquisitive, pretending he's Sherlock Holmes:

I have changed the "About Me" section in the right-hand column. Please read and give feedback as to whether or not I have bitten off more than I can chew.

I still have much to learn about Fusion but it has always endlessly fascinated me. This may or may not lead to future employment at the PPPL = Princeton Plasma Physics Laboratory in Plainsboro, NJ, or somewhere similar.

I have always loved Plasma, the 4th state of matter, as well.

Hopefully the "About Me" will change yearly as my knowledge and interests progress.

Time will tell, as it always does.

Future interests include but are not limited to: Quantum Chromodynamics, Quantum Hall effect and other types of Bose Condensate physics, Nonlinear Feedback Automatic Control Systems and Analysis, and Phenomenological Quantum Gravity beginning with Loop Quantum Gravity, Causal Dynamical Triangulations, and MOG (unless MOG is falsified in which case not-MOG).


Jérôme CHAUVET said...

Is it what your engineer work is about?... Wow, sounds complicated!

Steven Colyer said...

Is it any more complicated than yours, Jérôme? I honestly can't say I fully understand your paper, because that is not near my area of expertise. I am not an expert in even the issues of Biology, I'm just amazed at all the advancements like other intelligent laymen to your field.

Jérôme, it's like Integration by Parts or linear differential equations. Break the problem down into parts, solve the parts, and add the solutions together.

I can break my interests down if you wish, but I think you're intelligent enough to do so yourself. I will be applying the same to your paper once I catch up with the Biology, my friend.

Jérôme CHAUVET said...

Did you write anything about your work that one can download somewhere on the Internet?

Steven Colyer said...

No, I didn't, not yet, but I'm only getting started. Let me break it down:

- Quantum hydrodynamics
- Open toroids
- Sustained battery powered fusion reactions
- ceramic materials
- potential energy production
- potiential field uses

I'm not a fan of that last one. The third one is the most important.

The number one bugaboo in Fusion isn't how to achieve 100,000,000 degrees C. They've done that. Nor even how to sustain it. They've done that too.

No, the problem is how to do it such that energy out is greater than energy in. They haven't done that, although they get get closer each day.

Fusion is a field that has been around for a century, especially the last 60 years. It has had tons of money poured into it, with disappointing results (Dr. Octopus' efforts in Spiderman 2, especially) other than the H-bomb.

Theoretically, we KNOW we should be able to pump out more energy than we input, but have failed to do so, so far. It seems to be more of an engineering problem than a scientific one.

But whatever, it's quite the sexy challenge, to me.

Jérôme CHAUVET said...

So, you are proposing to control fusion, yes?

It seems to be more of an engineering problem than a scientific one.

I don't understand this assertion... Would you mean there is no fundamental limitation, only technical issues? I would rather think that the fact no technical solution emerges would be due to the fact a fundamental solution must be achieved before, no?

The fundamental problem is: How to create a little sun, in which fusion occurs... But fusion occurs because of the huge gravity force in it, so when diminishing the mass so as to have it in your hand (then in your battery), the gravity force vanishes, and fusion too... How too augment gravity in a small volume? Using very big atoms?... But the gravity field is too weak anyway... Generate local little black holes?... Perhaps, yes... But how?


Steven Colyer said...

Actually, the Science isn't the problem, it's the materials that face the plasma, I just learned last night. We've known about Fusion for a very long time. OK, there are some Science issues, which I'll get to in a bit.

I'm actually pretty depressed this morning, because I now realize Fusion isn't for me. I want to work on something that may see fruition in our lifetime, and reading around, Fusion won't be viable until 2050, when I'll probably be dead or in my 90's. If then, the 2050's. In the 1950's it was felt on-line commercial fusion plants would be viable in the year 2000. Not so, didn't happen.

OK, the materials question, from the Wiki article on Fusion Power:

Developing materials for fusion reactors has long been recognized as a problem nearly as difficult and important as that of plasma confinement, but it has received only a fraction of the attention. The neutron flux in a fusion reactor is expected to be about 100 times that in existing pressurized water reactors (PWR). Each atom in the blanket of a fusion reactor is expected to be hit by a neutron and displaced about a hundred times before the material is replaced. Furthermore the high-energy neutrons will produce hydrogen and helium in various nuclear reactions that tends to form bubbles at grain boundaries and result in swelling, blistering or embrittlement. One also wishes to choose materials whose primary components and impurities do not result in long-lived radioactive wastes. Finally, the mechanical forces and temperatures are large, and there may be frequent cycling of both.

The problem is exacerbated because realistic material tests must expose samples to neutron fluxes of a similar level for a similar length of time as those expected in a fusion power plant. Such a neutron source is nearly as complicated and expensive as a fusion reactor itself would be. Proper materials testing will not be possible in ITER, and a proposed materials testing facility, IFMIF, was still at the design stage in 2005.

The material of the plasma facing components (PFC) is a special problem. The PFC do not have to withstand large mechanical loads, so neutron damage is much less of an issue. They do have to withstand extremely large thermal loads, up to 10 MW/m², which is a difficult but solvable problem. Regardless of the material chosen, the heat flux can only be accommodated without melting if the distance from the front surface to the coolant is not more than a centimeter or two. The primary issue is the interaction with the plasma. One can choose either a low-Z material, typified by graphite although for some purposes beryllium might be chosen, or a high-Z material, usually tungsten with molybdenum as a second choice. Use of liquid metals (lithium, gallium, tin) has also been proposed, e.g., by injection of 1–5 mm thick streams flowing at 10 m/s on solid substrates.

Steven Colyer said...

Continued from Wiki:

If graphite is used, the gross erosion rates due to physical and chemical sputtering would be many meters per year, so one must rely on redeposition of the sputtered material. The location of the redeposition will not exactly coincide with the location of the sputtering, so one is still left with erosion rates that may be prohibitive. An even larger problem is the tritium co-deposited with the redeposited graphite. The tritium inventory in graphite layers and dust in a reactor could quickly build up to many kilograms, representing a waste of resources and a serious radiological hazard in case of an accident. The consensus of the fusion community seems to be that graphite, although a very attractive material for fusion experiments, cannot be the primary PFC material in a commercial reactor.

The sputtering rate of tungsten can be orders of magnitude smaller than that of carbon, and tritium is not so easily incorporated into redeposited tungsten, making this a more attractive choice. On the other hand, tungsten impurities in a plasma are much more damaging than carbon impurities, and self-sputtering of tungsten can be high, so it will be necessary to ensure that the plasma in contact with the tungsten is not too hot (a few tens of eV rather than hundreds of eV). Tungsten also has disadvantages in terms of eddy currents and melting in off-normal events, as well as some radiological issues.

Hi, Steve here again. I was going to suggest Ceramics, but the issue is a bit deeper than that. I also had an idea of a toroidal plasma gas stream embedded in said ceramics, but, no. Ceramic Engineering is one of the least known important advances of the 20th century. It's more interesting than you might think, and advances at a breathtaking pace. However, I cannot see myself devoting the next 5 years to mastering it and further it may not help this problem. Dangit.

At this point it looks like the engineering challenges are too great. Shoot, back to the drawing board.

On the positive side, at least I've eliminated one future possibility. Time for plan B.

Jérôme CHAUVET said...

Oh, an inventor has all issues constantly on mind, and then one day comes the light up to him !... Don't drop the arms Steven, simply bear things on your mind.

If I was to control fusion with my own original method, I would try to adapt a known device able to multiply forces to augment the output/input of energy ratio. E.g., I would try to adapt the lever effect. Very near to the fulcrum of the lever system I would easily get a huge pressure, in which I would try to install a fusion process... That's a concept of idea, I did not get into calculations to test the feasibility of it - not sure whether the mechanical moments suffices to get the approriate force... Maybe one should couple many such systems to augment the pressure as wanted.

Anyway, it remains to be developed further...


Steven Colyer said...

Hi Jerome,

Sorry to take so long to get back but I have a large family that has demanded my time of late, and being the family man that I am I always put the needs of my loved ones over this my hobby. Nevertheless, some interesting developments:

First, Scientific American's March issue has a wonderful article about Fusion Power, it's past, present and likely future, which comes to the same conclusions I did but in much deeper and richer detail.

Long story short: the Physics isn't the problem, the engineering is, specifically the materials needed to withstand the high temperatures, and the eventual brittleness of said materials thanks to the neutrons produced when a deuterium and tritium ion fuse to produce a helium nucleus and said neutron.

Second, the cost. Deuterium is cheap, we can get it from seawater. Tritium is insanely expensive. Even there, Tritium can through great ingenuity be created as a byproduct of the fusion reaction using something called a lithium blanket, the details of which are still in their infancy. We understand the physics, we just haven't built one.

Third, the cost again, in this case: Lithium. It's not infinite, and the ongoing Electric Car revolution will suck up quite a bit, so expect the cost of lithium to rise. The Chinese are cornering the market in Lithium as well.

Fourth, the costs again, in this case the pelleted approach that the National Ignition Facility in California uses. At present the highly-machined deuterium/tritium pellets cost approximately one million dollars each. That cost will come way down over time, but will it be reduced as much as a nickel apiece? Any fusion plant will be expected to run through 90,000 pellets per day.

Fifth, the time scale. ITER in France is being constructed as we speak, but first testing won't occur until 2026 by current projections, with the first viable plant not coming online until 2050. I will be dead by then, I hope. I don't want to live into my 90's, frankly, where a good day is one in which I remember my name, and have become a burden to society.

That last one is the kicker. I want to work on something that has a chance of seeing fruition in my lifetime.

So, no worries mate, I have many other interests and will move on. I will always follow developments in Fusion however as I like it, and wish good fortune to those who continue to tame it.