Fusion Process

[CrazyPensil 0]

I'm quite keen on nuclear physic and chemistry, but due to my teenager being, I'm not able to get all the knowledges I wanna gain=(

Now, I wanna ask: In a Hydrogen bomb,

We get a lot of H atoms under a big pressure; when the bomb collapses, they come too close, join together and form a He atom... My chemistry teacher told that that action frees a freat energy... But where is that energy taken from?! That's the question I ask you, dear ladies and Jeantlemen.... Hope you're good enough at Those subjects=)

[szupie 0]

I can't really make this sound confusing, because I'm not a master of this subject. So here's the basic idea. You have to know the formula E=mc². Matter can be converted into energy (and vice versa), and the amount of energy (E) that is produced depends on the mass (m) of the matter.When two hydrogen atoms fuse together to form the helium atom, the resulting He atom has less mass than the original two together. The "lost" mass is actually converted into a tremendous amount (mc²!!!) of energy.I don't know the exact process of how it is converted into energy. And I don't think my brain can handle it.

[mitchellmckain 0]

I'm quite keen on nuclear physic and chemistry, but due to my teenager being, I'm not able to get all the knowledges I wanna gain=(

Now, I wanna ask: In a Hydrogen bomb,

We get a lot of H atoms under a big pressure; when the bomb collapses, they come too close, join together and form a He atom... My chemistry teacher told that that action frees a freat energy... But where is that energy taken from?! That's the question I ask you, dear ladies and Jeantlemen.... Hope you're good enough at Those subjects=)

 

The basic idea of fusion comes from how the sun works, which is to push the hydrogen nuclei together with enough compressive force that they will form a larger nucleus with a lower total mass energy so that the extra mass energy is converted to radiation. In the case of atomic nuclei you can say that the nucleus is less than the sum of its parts, as strange as that may seem.

 

The mass energy per nucleon of the atomic nuclei decreases as you go down the periodic chart (up in atomic number) until you reach iron which is the lowest mass energy per nucleon and then this energy per nucleon of the nuclei begins to slowly increase again. So the stars produce energy by the process of fusion, compressing smaller atoms into larger atom and eventually to iron atoms and our fission bombs and nuclear plants produce energy by the process of fission, breaking down atoms much larger than iron atoms. The existence of uranium atoms on the earth is why we believe that our matter is a product of supernova explosions, for stars only make atoms of the atomic number of iron or less.

 

In the hydrogen bomb, however, we don't have the compressive power of the sun's gravity readily available and we use a few "shortcuts" to make it easier. Deuterium and Tritium, which are unstable isotopes of Hydrogen (with one or two neutrons in the nucleus along with the single proton) are used instead of hydrogen to make the to make the fusion reaction much easier to reach. The reaction is triggerd by a regular fission nuclear bomb using uranium 238 mirrors to reflect the neutrons from that explosion onto the hydrogen isotopes so that the resuting pressure and extra neutrons causes the hydrogen isotopes to fuse into the larger atomic nucleii (mostly Helium), converting the left over mass energy into an enormous amount of radiation. The resulting fusion explosion is powerful enough to fission the uranium 238 mirrors as well adding even more power to the explosion.

Edited October 29, 2006 by mitchellmckain (see edit history)

[evion 0]

The basic idea of fusion comes from how the sun works

Speaking of which, is it possible that the Earth's inner core is undergoing constant nuclear fusion? I am still not sure if the temperature present there is high enough for a reaction like this to occur. It would be amazing if the scientists of the future will be able to both fuse and fiss (or fissionize? ). I'm much convinced that the incident in Chernobyl was intentional, and that proper handling and use will not result in much chance of danger.

P.S. And i really started getting into this topic when my teacher mentioned something about induced transmutations where synthetic elements can be made by joining atoms of certain elements together. (Basically, my reaction was "So we can make gold now?" )

[yeh 0]

Basically, my reaction was "So we can make gold now?" )

Well... i'm not sure about gold but you can certainly make diamonds. Sounds good.. hehe...

Speaking of which, is it possible that the Earth's inner core is undergoing constant nuclear fusion? I am still not sure if the temperature present there is high enough for a reaction like this to occur. It would be amazing if the scientists of the future will be able to both fuse and fiss (or fissionize? ). I'm much convinced that the incident in Chernobyl was intentional, and that proper handling and use will not result in much chance of danger.

Actually scientists can already "fissionize" stuff. That is how you get nuclear energy presently. As for fusion, I'm waiting for the technology to progress and mature to a stage where we can harness energy for daily use and not just for mass destruction purposes. Imagine a clean, infinite energy source.
As for the Chernobyl, I don't know why you think it is intentional. Nuclear power stations are not inherently safe. When people mention "not much danger", they are forgetting the effects of a nuclear meltdown and its associated radioactive costs. Just to illustrate my point. If you ever need to go for a major surgery and the doctor tells you that there is a 1% chance of failure, it seems like a good odds to me and I would certainly go for the surgery. But if you have a nuclear power station and the odds of them blowing up is 1%, do you still think it is acceptable to have a nuclear power station near your home? I certainly would not.

[szupie 0]

The prime energy producer in the sun is the fusion of hydrogen to helium, which occurs at a minimum temperature of 3 million kelvins.

-Wikipedia - Stellar nucleosynthesis

The temperature of the Earth's core is only a few thousand Kelvins, definitely not over ten thousand. So there is definitely no nuclear fusion going on in the core (unless Earth has found some way to produce cold fusion 'o' ).

 

But yes, we can use fusion to make gold. I think they use platinum (the element before gold) and add something to it (hydrogen?). However, since fusion reactions require a tremendous amount of energy, it is not cost-effective to do so.

And to yeh, creating diamonds doesn't require fusion (diamond is just highly compacted carbon), but the resulting diamond doesn't look the same as natural diamonds, so it's not worth it to make them either.

[mitchellmckain 0]

Speaking of which, is it possible that the Earth's inner core is undergoing constant nuclear fusion? I am still not sure if the temperature present there is high enough for a reaction like this to occur.

No. The temperature and pressure is not high enough but that doesn't matter because its mostly iron and nickel at the center anyway. Nickel would require temperatures and pressures much much higher than the center of the sun to fuse and iron would require a supernova. The only planet which comes close is Jupiter, which is still 13 times too small to fuse deuterium, and 70 times to small to be a full star. But at least Jupiter does have compressed metalic hydrogen at its center. At a 1000 times the mass of Jupiter our sun is massive enough to be a fairly hot star compared to most, yet small enough not to burn out too quickly like the really hot stars.

P.S. And i really started getting into this topic when my teacher mentioned something about induced transmutations where synthetic elements can be made by joining atoms of certain elements together. (Basically, my reaction was "So we can make gold now?" )

Yep. The dream of alchemy has been realized. We can turn lead into gold. But it is so expensive to do so that it is not worth the effort.

As for the Chernobyl, I don't know why you think it is intentional. Nuclear power stations are not inherently safe. When people mention "not much danger", they are forgetting the effects of a nuclear meltdown and its associated radioactive costs. Just to illustrate my point. If you ever need to go for a major surgery and the doctor tells you that there is a 1% chance of failure, it seems like a good odds to me and I would certainly go for the surgery. But if you have a nuclear power station and the odds of them blowing up is 1%, do you still think it is acceptable to have a nuclear power station near your home? I certainly would not.

Yes running a nuclear reactor is like balancing a pencil on its point (on the moon) for the reaction will tend to die down or speed up so you have to watch it in order to adjust the control rods to keep the reation steady. The control rods are materials that either slow down the reaction by absorbing neutrons or speed up the reaction by multiplying neutrons.

[zerofool2005 0]

This has been a great read. I always loved to find out how things work and what is done to do that. this just fuels me even more to find things out. just a pity out schools dont teach advanced sutff like this. At least mine doesnt

[yeh 0]

Oopps... szupie is right about the diamond thing. Looks like I gave an example that is non-related to the topic in discussion. Hehe...