What I don’t understand about Nuclear Fusion

[ChrisGreaves]

As distinct from nuclear phission, which is where somebody tries to get into your nucleus to get passwords of your bank account.

I was thinking along the lines of nuclear power generating electricity to heat the fat to make the fission chips ...
Cheers, Chris

[Leif]

Chris, wouldn't it be easier on the mind if you just got one of these to gaze at longingly through the dark winter evenings?

The Davenset Atomic Reactor Made to Order Retro 1960s?

[HansV]

That's marvelous!

[ChrisGreaves]

Chris, wouldn't it be easier on the mind if you just got one of these to gaze at longingly through the dark winter evenings?

Gaaaaaaah! I just spent a small fortune having the faux-stone Masonite ripped out from the wall where the wood stove used to be.

Also it would be a lot easier on my mind if I replaced those teeny-tiny bolts in the laptop rather than waiting until the lid separated from the case and yanked a very small thin cable from what I think is the hard drive. One of these days I am going to seek a cure for procrastination.
Cheers, Chris

[stuck]

When I was at school in the 1960s, fusion reactors were 10 to 15 years away. We hear the same claims every few years, and they are still 10 to 15 years away now.

Thinking about this again...

When my sons were at school in the 2000s, fusion reactors were 10 to 15 years away. We hear the same claims every few years, and they are still 10 to 15 years away now.

Ken

[ChrisGreaves]

...We hear the same claims every few years, and they are still 10 to 15 years away now.

So these fusion-reactor releases are the same as every study by a post-grad, usually reported in a national newspaper, that ends with the stock phrase "More research is needed" as a thinly-disguised plea for funding.
Please see also this cartoon (don't forget to hover your mouse over the cartoon)
Cheers, Chris

[Leif]

...successfully produced a nuclear fusion reaction resulting in a net energy gain...

Hmmm.

According to Breakthrough in nuclear fusion energy announced - BBC News:

...although the experiment got more energy out than the laser put in, this did not include the energy needed to make the lasers work - which was far greater that the amount of energy the hydrogen produced.

Which to my simple mind, means that there was not an "energy gain". Scientists are beginning to sound like politicians these days...

[John Gray]

Looks as though I should have listened to Drs Adam Rutherford and Hannah Fry on The Puzzle of the Plasma Doughnut.
[Hope you can hear this BBC programme in your locale.]

[LineLaline]

...successfully produced a nuclear fusion reaction resulting in a net energy gain...

Hmmm.
According to Breakthrough in nuclear fusion energy announced - BBC News:

...although the experiment got more energy out than the laser put in, this did not include the energy needed to make the lasers work - which was far greater that the amount of energy the hydrogen produced.

Which to my simple mind, means that there was not an "energy gain". Scientists are beginning to sound like politicians these days...

Dammit. Get on with it.
I though did like the presentation and am excited. It would be a good step forward, I think.
I wonder how some parties will spin it to become something negative because the speech was very pro-Biden.

[LineLaline]

OH and by 'Get on with it' I mean that I really look forward to seeing this all pan out as useful energy! Not that Leif should get on with it

[ChrisGreaves]

According to Breakthrough in nuclear fusion energy announced - BBC Newsn:

... there is some text "And importantly, the process produces no greenhouse gas emissions and therefore does not contribute to climate change." which leads me back to one of my original points.
The argument quoted here is "no greenhouse gas emissions" reducing climate change, but surely simply using more energy (for our human lifestyle) leads to climate change.
Imagine all 8,000,000,000 of us deciding that since electrical energy is so cheap, we can all afford a 2,000w baseboard heater in every room of our house ...

FWIW the same point is made at about the 26m50s point in the podcast of "limitless clean energy", but if one is profligate with limitless and cheap energy, one ends up with a super-hot Earth, No?
Cheers, Chris

[GeoffW]

I was thinking along the lines of nuclear power generating electricity to heat the fat to make the fission chips ...
Cheers, Chris

Or I could have mentioned the nuclear confusion going on ATM.

[Graeme]

IIRC the little I learned in high school physics class in the 1950s, the law of conservation of energy states that energy can neither be created nor be destroyed. Although, it may be transformed from one form to another. If my recall is right, I need an explanation of how the reaction created a net energy gain.

That is correct, but E=MC², so when two protons are forced together in the fusion process, one of them turns into a neutron, which has less mass. The missing mass is spat out in the form of a neutrino and a positron. The positron annihilates with the first handy electron to float by and two photons are released.(high energy gamma ray)

As least, that's what happens in stars!

I think nuclear fusion is the future for our energy needs but I have little faith in our ability to contain a process that ordinarily needs the mass of a whole star to keep it going. Perhaps we'll crack it in 30 years or so!

Regards

Graeme

[Graeme]

The argument quoted here is "no greenhouse gas emissions" reducing climate change, but surely simply using more energy (for our human lifestyle) leads to climate change.
Imagine all 8,000,000,000 of us deciding that since electrical energy is so cheap, we can all afford a 2,000w baseboard heater in every room of our house ...

https://en.wikipedia.org/wiki/Kardashev_scale

[stuck]

...Which to my simple mind, means that there was not an "energy gain". Scientists are beginning to sound like politicians these days...

Absolutely! I was really annoyed by the BBC News at 10 coverage of this 'breakthrough' because they did NOT mention that crucial fact.

Ken

[PJ_in_FL]

... One of these days I am going to seek a cure for procrastination.
Cheers, Chris

I have that cure for you Chris. I'll try to get around to posting it in a few days or so.

[BobH]

With nuclear fission reactors, there are spent rods that remain radioactive for millennia (I think). The cost of disposing of those rods and the costs for damage done to Mother Earth is disposing of them is not calculated into the costs of electricity produced, as I understand it. I guess the costs of construction and security are so great that those piddling costs might easily be ignored.

Is there a similar cost with fusion reactors? I realize that we don't actually have them outside of WMD; however, do the theories about their use for power generation include any residual or simultaneous unwanted output?

[ChrisGreaves]

I have that cure for you Chris. I'll try to get around to posting it in a few days or so.

PJ, this sounds like one of those "within the next ten or fifteen years" deals. Just how many billion dollars will this cost me?
Cheers, Chris

[Jay Freedman]

The mention of "doubling" the previous record probably refers to the length of time that fusion could be sustained, not the amount of energy it produced.

Hi Jay; I may have tripped myself up here, but wouldn't an increase in the period of fusion lead directly (although maybe not in a linear fashion) to and increase in the amount of energy produced? I am thinking along the lines of "increase the period from five seconds to ten seconds and you have approximately doubled the amount of energy produced"?
Cheers, Chris

I'll give you a "maybe" on that, but as usual the devil is in the details.

I read elsewhere that the experiment being discussed involves injecting a small pellet containing hydrogen into a chamber and firing a large number of high-powered laser beams at it simultaneously. This compresses and heats the hydrogen, which undergoes fusion and releases a burst of energy that's absorbed in the chamber walls. (Many fussy details omitted.)

The net energy production from a single pellet is the amount of energy that reaches the outside of the chamber minus the energy used by the lasers (and anything else in the system that involves energy use). I assume that is a small but positive number of joules. The intention is to repeat that at a rate of thousands of pellets per second to produce a commercially viable energy source. There will be a lot of engineering needed to reach that goal.

[ChrisGreaves]

The net energy production from a single pellet is the amount of energy that reaches the outside of the chamber minus the energy used by the lasers (and anything else in the system that involves energy use). I assume that is a small but positive number of joules. The intention is to repeat that at a rate of thousands of pellets per second to produce a commercially viable energy source. There will be a lot of engineering needed to reach that goal.

Hello Jay.
My knowledge of the fusion process is less than that of the programming process, so I think now of my question and your answer in terms of programming a computer.
When a prospect asked me if I could write a program to "do this" I would think quickly and find that there was no theoretical reason why it couldn't be done.
Then I would go home and find/create code that showed the essence of the task. sometimes calling it a "Proof of Concept", which provided grounds for producing a skeletal application, enough to convince the prospect to part with some money.
Work progressed until I could "do this" with parts of a simple document, which I would take to the client.
Then we would push a client's document through the program and with success declare that the project could now go full-steam ahead.
There followed 1/100,000, 1/10,000 tests and so on until we could "do this" right across the client's LAN.

It seems to me that this month's Fusion announcement is at the stage of "doing this" with a simple document, or at most, "doing this" with a half-dozen simple documents.

So the jubilation is really because another milestone has been reached along the road of development, with the added joy that we can now see that the end of the road can be reached. That is, that the white-coats are now genuinely confident in saying "an increase in the period of fusion [will] lead directly ... to an increase in the amount of energy produced!"

Cheers, Chris