ITER Talks: Introduction to the ITER nuclear fusion research project (video)

[gary]

In this 23 July 2021 53 minute video, Laban Coblentz provides an introduction
to the ITER Tokamak, a joint multi-billion dollar nuclear fusion research
project being undertaken by 35 nations in France.

Full of gee-whizz data such as an explanation of why it is sized as it is
(in order to achieve a ten times ratio of output thermal power to input thermal power -
a ratio known as 'Q') and the fact that this 830 cubic metre vessels only uses 2 to 3 grams of
hydrogen-deuterium fuel.

https://youtu.be/kDaTQSmsJC8

[colour-coded]

Very interesting project and great presentation by Laban.

[glend]

You may find the article on the National Ignition Facility experiment interesting as well:


https://www.sciencemag.org/news/2021/08/explosive-new-result-laser-powered-fusion-effort-nears-ignition

[multiweb]

We should have answers within the decade. Exciting times. First thing we need to do is scrub all that CO2 back with a true unlimited green source of energy.

[colour-coded]

What is surprising to me is the level of cooperation between countries. So unlike to the current state of affairs. China and India, Russia and the rest. Unlike in Space, where are everybody started to pull their blankets. I was browsing through various RAN's websites ( Russian Academy of Science) and in general, it's a good impression, very positive vibe towards the project.

[multiweb]

Energy control is strategic. Nobody wants to be left out in the dark.

[colour-coded]

Plus it's too expensive and no one is able to pull it on its own, I guess.

[multiweb]

Absolutely. The cost is massive.

[colour-coded]

Apparently, Australia has also got invited to build a measuring system, https://iter.anu.edu.au/
I hope they will find the required $30 m to develop this tech. Such a great opportunity.

[AdamJL]

All that money on this project and they use the worst green screen technology and video production ever. That was like watching a video from the year 2000

[colour-coded]

Ever? /s

[AdamJL]

ever :)

[colour-coded]

Anton made a video about it today - https://youtu.be/5M5U2_9eEgM

[gary]

31 Aug 2021 "Celebration for the completion of the first ITER central solenoid module".

The central solenoid initiates and stabilises ITER's plasma.
It forms the heart of ITER's magnetic confinement.

Weighing 1000 tonnes and 5 storeys high, 15 million amperes pass
through it to generate 13 Tesla, about 208,000 times stronger than the
Earth's own magnetic field.

Video 1h3m :-
https://youtu.be/opZPJKZ0rk0

[colour-coded]

Here we go - How close is nuclear fusion power? (https://youtu.be/LJ4W1g-6JiY)

[xelasnave]

Mmmm at times I think the quest is no better than the guy Flash posted about today in general chat claiming "free" electricity.
What I find curious is why it is a few light elements that give off energy and yet with heavier elements energy is required..could they be wrong about light elements giving off energy in fusion? Why the difference?
alex

[Lariliss]

1. The difference between light and heavy elements depends on a particular element.
When two light nuclei are fused together to produce a heavier nucleus, the mass difference is converted into energy.
The issue of fusing Hydrogen into Helium releases a large amount of energy. Fusing heavier elements releases less energy.
Nuclei of heavier elements require additional energy to fuse and fusion reactions require energy rather than produce it.
Heavy elements produce more energy through fission.
Fusion produces more energy if it involves light elements and fission produces more energy if it involves heavy elements.

At the same time the preference is given to reactions that are safe from a control point of view

https://www.energy.gov/ne/articles/fission-and-fusion-what-difference

2. I also want to agree to be fascinated by the degree of cooperation between countries within technological tasks, unprecedented before in history.
It benefits with the speed of solutions, discoveries and technology evolution. These kinds of huge projects need a lot of experts, specialists, and tests to be involved. Hiding information and trying to make it alone would sound like a waste of time, resources and failure.

[xelasnave]

Thank you for taking your time to explain things so clearly.
However the question remains in my mind as to why it is that light elements give energy and are the exception to the majority of elements, those being the heavier ones, who require energy ...I understand it comes down to extra mass after the event and I expect that E=MC2 is used to arrive at the "extra" energy...further could there be a mistaken interpretation of the light element observation here such that the "spare" mass does not convert to energy.
Perhaps you know of experiments that conclusively establish the matter.
I have little knowledge in these areas and realise my question probably would not be asked if I had a reasonable knowledge of the subject but given that I am in the presence of someone who has what would seem a decent grasp of the subject I am driven to ask.
Alex

[Lariliss]

Thank you, Alex.

This is quite true.

For practical part I might add this:
1. One reason is that the controlled chain reaction during fission is capable of giving energy from U233, U235 (occurs naturally), Pu239, Pu241.
If there is no chain reaction during fission, it would be necessary to provide a thermal neutron for each nuclear reaction "manually".
2. Fission gives much more energy than one reaction of fusion, but the fusion is more efficient per kilogramme of matter.
3. Weizsäckers formula (https://en.wikipedia.org/wiki/Semi-empirical_mass_formula#Examples_of_ consequences_of_the_formula) about binding energies in nuclei may help understanding the calculations.

And a reference:
https://www.researchgate.net/post/Why-are-light-or-heavy-elements-good-sources-of-nuclear-energy-and-why-intermediate-elements-are-not

[xelasnave]

Thank you for helping me understand. In truth this stuff is somewhat beyond me because unfortunately my education in math is minimal, however I dont give up working on the basis of I learn a little more about things each time I read material...I dont give up in frustration

I will enjoy following up on this subject.
Alex

[gary]

Hi Alex,

In order to fuse the nuclei, you have to overcome the repulsive force
of the protons. Lighter elements can be more readily fused because there is less
protons and therefore less electrostatic repulsive force. It transpires
for these lighter elements when you fuse them you get an net energy gain.
That is, the energy it produces once you manage to fuse them is greater
than the amount of energy you had to put into getting them to fuse.
Once you get to iron it takes more energy to fuse them than you get out.

Best example is stars.

Tried and tested here on Earth in the form of thermonuclear bombs.
Bikini isn't just famous for skimpy two-piece beachwear.

[xelasnave]

Thank you Gary you have understood what I was trying to identify and now that you have explained it I really do not know why I could not have worked that out for myself as it is so obvious... right under my nose yet I did not jerry.

The stars yes which made me hesitant to even ask if they could be mistaken because if they were a new explanation for the Suns energy production would have been needed...I think I was really just trying to find out why the difference between light and heavy elements...

And again the existence of the hydrogen bomb and where it gets its extra clout would need a different explanation..

I expect very few people think of Bikini Atol but a lot think about the swim wear.

Thinking casually about the prospect of creating a fusion power plant it occurred to me that the thing missing, that is plentiful on the Sun is gravity.
To replicate that energy (required for containment) I expect that is where the magnets come in...and so to power those magnets I expect the Sun does not have that issue as it has 'free' gravity...sorry about my clumsy explanation...do you see what I am trying to "say"?

Alex

[gary]

Thanks Alex,

In addition to that, in order to to provide hydrogen atoms enough energy to
overcome repulsion between the protons, fusion requires extremely high
temperatures, over 100 million degrees Celsius (10keV).

So the challenge on Earth is to engineer a vessel that contain this
extremely hot plasma. That is where the 'tokamak' comes in.
It uses powerful magnetic fields to confine the plasma in the shape of
a torus, lest it touch the walls of the machine.

By definition, these extremely hot, high energy ions and electrons in the
plasma have correspondingly high velocities. If they aren't confined, they
rapidly cool. It transpires that the geometry of circulating them with a
toroidal solenoid is a geometrically convenient shape that exploits the
geometry of magnetic fields.

Tokamaks aren't the only type of fusion plasma magnetic containment
devices, but after decades of experimentation it is the one those in the
field bet on giving the best chance of success in the experimental ITER
device.

Stars are self-contained fusion reactions that are free-standing in
space holding their plasma together with gravity. The gravity creates
a inward force and the energy from fusion and outward force in a balancing
act. If the star is sufficiently large, as it fuses heavier and heavier
elements together advancing up through the periodic table, it will
eventually undergo gravitational collapse.

Plans are already underway for the successor machines based on the
outcomes of ITER referred to as DEMO (short for Demonstration Power
Plant). 15% larger than ITER, they are being designed to deliver
2 gigawatts of fusion power on a continuous basis and the goal is to
have them in operation around 2050.

[xelasnave]

Thanks Gary
Alex