To Create a Star on Earth...

I read about this last year and something reminded me of it today, so I thought I'd post it here.

Very basically, scientists at an American institution plan on creating a tiny star in the laboratory by nuclear fusion.

Here's a link to the NIF website where it explains the processes/technology involved in basic terms.

Here's an article from The Telegraph from last December talking about the project.

And lastly, here is a video from Youtube of a similar project:

https://www.youtube.com/watch?v=SxTMiDXpkHc

What you're seeing is, basically, a small star "igniting" by means of nuclear fusion.

jumpguy

That's pretty cool. I wonder how they recorded that inside the extremely hot reactor!

Wasn't MAST that thing they were pouring billions into in France? Just remember reading about it somewhere...

Should we continue with nuclear fusion before it become a burden to global security like fission did though?

elpresdentde

from what iv read fusion i dont think fusion can be weaponised and the only waste product is water

jumpguy

elpresdentde wrote: »

from what iv read fusion i dont think fusion can be weaponised and the only waste product is water

The hydrogen bomb depends on a fusion reaction created by an initial, smaller fission reaction. Water is not a waste product.

karlog

Didn't they try that in spiderman 2.

No good can come from this!!!!!

Sleipnir

They're just trying to fill the void that Michael Jackson left.

Looks pretty interesting, I love the little 6-step recipe on the right of the main page.:D

Does the picture on the Telegraph's webpage remind anyone of the movie "Event Horizon"?
http://www.wallpaperbase.com/wallpapers/movie/eventhorizon/event_horizon_6.jpg

AlmightyCushion

They're working on this in France and the UK I think. Last time I checked they actually have started the fusion process but they can't keep it going as they have no way to contain it.

jumpguy

AlmightyCushion wrote: »

They're working on this in France and the UK I think. Last time I checked they actually have started the fusion process but they can't keep it going as they have no way to contain it.

I thought it was because there was no way to sustain it! Then again, that's probably a factor, don't know any material on Earth that can stand temperatures in the billions of Degrees Celcius.

Sleipnir

Also, they wouldn't know what to do with it if they could contain it and keep it going.
The obvious desired end result is one which is self-sustaining. Stars can do it simply because they have vast amounts of hydrogen to convert to helium.


To make it into a useful form of energy production, you'd want a way to create thousands or millions of these micro stars every second, each one creating 10 to 100 times more energy than was used to ignite it.

AlmightyCushion

jumpguy wrote: »

I thought it was because there was no way to sustain it! Then again, that's probably a factor, don't know any material on Earth that can stand temperatures in the billions of Degrees Celcius.

I'm not an expert on this (seen a really good bbc documentery about it a few years back and that's the sum of my knowledge on it) but I think once the reaction starts it's self sustaining. I could be wrong though.

AlmightyCushion

Sleipnir wrote: »

To make it into a useful form of energy production, you'd want a way to create thousands or millions of these micro stars every second, each one creating 10 to 100 times more energy than was used to ignite it.

They'd need to keep it going as the massive amount of energy needed to start the reaction doesn't exceed the amount it would create for a second or two. Once they have the reaction started they don't need to put any more energy into it to sustain the reaction.

Sleipnir

Also, they would collapse as the only reason stars don't collapse due to their own gravity is because their internal pressure is pushing against gravity.
When the star's gravity overcomes that internal pressure, then the star collapses.

We can't change gravity artifically, so they can't really control the balance between it and the pressure that the fusion reactions cause, hence, with this micro star, gravity always eventually overcomes the internal pressure of the star once the fuel (hydrogen) starts to run out.

Sleipnir

AlmightyCushion wrote: »

Once they have the reaction started they don't need to put any more energy into it to sustain the reaction.

Only fuel!

jumpguy

AlmightyCushion wrote: »

I'm not an expert on this (seen a really good bbc documentery about it a few years back and that's the sum of my knowledge on it) but I think once the reaction starts it's self sustaining. I could be wrong though.

Really? How come when hydrogen bombs do not go to destroy earth?

AlmightyCushion

jumpguy wrote: »

Really? How come when hydrogen bombs do not go to destroy earth?

I reckon that when the hydrogen bomb goes off it doesn't generate enough heat to heat the hydrogen in the air to the required temperature. I'm completely out of my element here so I could be miles off.

jumpguy

AlmightyCushion wrote: »

I reckon that when the hydrogen bomb goes off it doesn't generate enough heat to heat the hydrogen in the air to the required temperature. I'm completely out of my element here so I could be miles off.

Not sure...question for a physics buff no doubt. Always wondered what stops the chain-reaction, even in fission bombs.

watty

Fusion can be contained and sustained.

It's just currently the input power for Containment and Sustaining is more than output:(

But if you surround the reactor with Nuclear Waste from Fission power stations, the Neutrons cause the waste to convert to less dangerous materials (about 1% as dangerous). The reaction heat can make steam to generate electricity, and you might then even have a net production of elctricity. However even if it needs a net input it's worthwhile as it would make ordinary Fisson Nuclear Reactors 99% more environmentally friendly.

There are two main schools of thought on Fusion power...

1) It's possible. We just need a big enough reactor to get more power out than we put in.

2) It's possible. We just need a big enough reactor to get more power out than we put in. Big enough might be somewhere between size of Jupiter and a Star

watty

jumpguy wrote: »

Not sure...question for a physics buff no doubt. Always wondered what stops the chain-reaction, even in fission bombs.

Lack of containment. Even on a "Hydrogen" or "thermonuclear" bomb http://en.wikipedia.org/wiki/Teller%E2%80%93Ulam_design the containment design of the trigger blast is critical.

Suitable further fuel in the environment is not dense enough to sustain reaction, too many neutrons are lost. A Star's gravity provides the "containment" or required density. There is thus a minimum size to a Star.

With a mass only 93 times that of Jupiter, AB Doradus C, a companion to AB Doradus A, is the smallest known star undergoing nuclear fusion in its core. For stars with similar metallicity to the Sun, the theoretical minimum mass the star can have, and still undergo fusion at the core, is estimated to be about 75 times the mass of Jupiter. When the metallicity is very low, however, a recent study of the faintest stars found that the minimum star size seems to be about 8.3% of the solar mass, or about 87 times the mass of Jupiter. Smaller bodies are called brown dwarfs, which occupy a poorly defined grey area between stars and gas giants.

http://en.wikipedia.org/wiki/Star

Jupiter's Mass is about 1/1,000th of our sun, so roughly the minimum mass of hydrogen for spontaneous and sustained fusion is about 1/15th the mass of our sun. Likely a lower mass could be artificially started in theory.

It would seem that due to concentration we are safe from "run away" Fission or Fusion reactions started by a weapon.

InvisibleBadger

If you search Star on Earth on youtube, you will find a great Horizons documentary on fusion by prof Brian Cox. There is a great part in it where he discusses with another bloke what energy could possibly replace oil, it's a jaw dropper.

elpresdentde

jumpguy wrote: »

The hydrogen bomb depends on a fusion reaction created by an initial, smaller fission reaction. Water is not a waste product.

sorry got my facts mixed up