Page 1 of 2

Gaining some energy back from our fusion reactors

Posted: Sat Jul 04, 2020 5:31 pm
by Erich Gazenko
I have a couple ideas on how we can get some energy back from our fusion reactors. It will not be totally efficient but it might give us a foundation to start on. I am not sure if any one has posted something like this or already built something like this.

First idea. A heat sink in the vacuum chamber. The heat sink will need to be near the fusion process but not to close to where it interferes with the reactor. The heat sink goes up through the chamber and boil water and the steam would turn turbines. The only problem is the temperature. I am not sure if a fusion reactor would generate the heat needed to boil water.

Second idea. Solar panels. Putting solar panels at the view port of the reactor. The problem would be whether the fusion reactor would provide the needed amount of light energy.

Those are the only ideas I have right now. Is that the only thing fusion reactors produce? Heat and light energy? Of course it also makes tritium.

I am hoping to receive constructive criticism and knowledge.
Tell me if I did anything wrong in my post. I am fairly new to

Re: Gaining some energy back from our fusion reactors

Posted: Sat Jul 04, 2020 11:00 pm
by Dennis P Brown
First, one must calulate the usable waste heat available (look at the Gibbs). This can be done by calulating the heat capacity of the extremely low pressure gas and what one can expect out. Do these calculations and the answer to your question will be rather apparent.

As for solar panels that calculation of available energy is trival and I'm surprised you didn't do that first before making this suggestion. To get you started simply look up the response of the given solar cell for the visible spectrum, the cells effeciency for those wavelengths and measure the light intensity and spectrum of a fusor - a good approximation if one doesn't want to do that experiment is assume a tungston filamant spectrum for 1500 C or there about with a power input into the filament of say, 1000 watts. Your answer is obvious.

As for tritium, please read the FAQ's on this subject here at the forum. That will provide your answer.

A good idea for any beginner with no background in physics would be to read the various FAQ's here on various parts of the fusor and related physics.

Re: Gaining some energy back from our fusion reactors

Posted: Sat Jul 04, 2020 11:26 pm
by Erich Gazenko
I kinda understood your explanation on the heat, so basically it is not going to work because of the way heat travels through a vacuum, I am not sure why I did not consider that. But for the solar panels I did not understand at all. Could you please make that more simple for a newbie like me? And if both of theses cannot work how can we get energy back from the fusion? Thank you very much for the explanations.

Re: Gaining some energy back from our fusion reactors

Posted: Sun Jul 05, 2020 12:34 am
by Rich Feldman
Suppose you could magically capture 100% of the energy released by D-D fusion events in these fusors.
Do you understand that it's no more than 1/1,000,000,000 of the electric power we put in to the fusor?
It would be 1 billion times more efficient to skip the fusor, and send what would have been fusor input power
directly to lights and motors and battery charging.

Is it possible to read FAQs here for more than a few hours without knowing that?

As for tritium, even if it were legal to buy at any science store, and it were not "a material we don't talk about here"...
it's produced in fusors at about the same rate as free neutrons, and is millions of times harder to detect (which is why we count neutrons instead of tritons).
Normally it gets pumped right out of fusor and exhausted into the room, at a rate much too slow to be of any consequence as a radiation hazard;
in fact I've never heard of any amateur fusioneer successfully capturing enough tritium to detect.

This discussion really belongs in the New User Chat Area, not Theory. Go do some more reading.

Re: Gaining some energy back from our fusion reactors

Posted: Sun Jul 05, 2020 4:27 am
by Richard Hull
It is physically impossible to capture or any usable fusion energy from any fusor ever built. They are the FAQs!
The classic next question from newbies when told this is............Why am I here?.........Why would I want to do this? If there is no real usable fusion energy to be extracted by doing real fusion in a fusor what is all this about???

Richard Hull

Re: Gaining some energy back from our fusion reactors

Posted: Sun Jul 05, 2020 11:10 am
by Dennis P Brown
Richard, as his usual, hits the gold; why are you here? Why did I join? Why do most people join and post here? These questions share one common answer - to learn about fusion via a device called a fusor; this is not and never will produce usable energy (see FAQ's). But I wanted you to calculate that impossiblity yourself to learn. That is the best method. As an engineer that is the best way.

The FAQ's contain a vast amount of useful, technical and practical knowledge about fusor's, and also fusion physics in general. But here one has to ask, 'Why all this information on a device that is useless for energy?'

Because what unites us here is the desire to learn and then try our own hand at building something applicable - a simple demo fusor, a real fusor, or even an experiment in fusor research. We learn a great deal over and above what a FAQ or even reading a plasma text book (through some here do that as well!)

Simply speaking (and my view) few sites exist that offer not just such a vast knowledge base but people online that can aid you in building your own devices - from elementary but very practical vacuum engineering to abstract plasma theory; and if you decide to build any level of device (even just a new power supply, or detector) people here want to learn about it and aid you, as well.

AS for the heat recovery problem, the Carnot cycle law guarentee's you will never get back much more than a fraction of usable energy from any heat sources (at best about 38% conversion.) As for solar cells, not including losses from ineffecency of said cell (about 28% photons can be 'captured' but only in a narrow band of the spectrum to create electricity) getting near all the photons is impossible and ...well, the list of losses goes on. I offered you a primative light source device (light bulb) that would be close to a fusor in energy output to do your calculation since building a real fusor for the experiment would be pointless. We do not like spoon feeding people on answers they can get from an FAQ or do themselves in a trival manner (look up solar cell efficencies, for instance.)

Here I've given you detailed physics based answers to your questions (google those subjects and read on your own - I guarantee you'll learn a great deal); as such, you really need to read on these subjects (some) if you are interested in anything to do with energy production and conversion and be capable of discusing these concepts in a reasonably knowledgable fashion. Asking questions here is fine but do try and not ask questions that are answered in the FAQ's. Also, as Rich said, do read some on a topic area first and try to answer your own question by learning about the subject on an elementary level; then if still not sure, do ask here.

Re: Gaining some energy back from our fusion reactors

Posted: Sun Jul 05, 2020 7:07 pm
by Erich Gazenko
Thank you for the explanations. I now have a better understanding of fusion reactors. My original plan was to build a fusion reactor whether energy is made or not, and that still did not change. But your attitude on making energy from fusion is not very optimistic. Eventuality it will happen, right? I sure hope so. I am not really the one here who could talk but why don't you guys still try to find a way to make energy from fusion reactors? I think it still could be possible. The home page of this site states "Fusion may sound like an exotic, "impossible" feat. But the fact is people like you are achieving the "impossible" on an almost daily basis. It is only a matter of time before somebody stumbles on the breakthrough that we are all hoping for."

Re: Gaining some energy back from our fusion reactors

Posted: Sun Jul 05, 2020 10:41 pm
by Dennis P Brown
I think you do not understand the difference between the types of fusion that we (the fusor community) and major fusion centers (ITER, for instance) perform. Fusion like how the Sun works is what fusor's do - i.e. fusion via tunneling. Fusion in a magnetic or inertia drive system is brute force K.E. overcoming the Coulomb barrier. The later, in theory can produce net energy, the former, except for conditions like the Sun, NEVER can - i.e. a fusor. Again, read on a subject and you will learn valuble information.

Building a fusor allows one to create neutrons via tunneling fusion in the home, and except for the x-rays hazard (solely due to the electric potential - NOT nuclear), produces no significant radiation from the fusion. Nor energy.

A fusor is literally a process exactly like the sun; hence this is often called a Star in a bottle. The creation and detection (not so easy) of fusion via tunneling is a great and fun achievement that few have managed to do. Most come here, have big plans and quickly fade away never to be heard from again. Building a real fusor is a worthy goal and one can learn a great deal in doing this - and we award people here with entry into the 'Neutron Club' when they do; however, the x-ray radiation is a real hazard and the voltages are absoultely lethal.

Read the FAQ's on building a real fusor and you will either be inspired or soon disappear never to be heard from again. Your choice.

By the way, there are two major ways to do fusion here: buy everthing and the cost is very high (est. vary but $5 K is close.) Or build most of the stuff yourself - requires a great deal of knowledge (see the FAQ's and many, many posts on this forum), no small amount of skill and a fantastic level of determination.

Aside: whether the K.E. guys ever achieve real energy above breakeven (my money is on the Stellarator in Germany) or not, fusion energy is far too complex and expensive to have any impact on the world's energy needs for many, many years even if someone had a major break through in the next five years. Please read up on this subject before asking any more questions on fusion energy. Rather, decide on whether to disappear or try and build a real fusion device like a fusor. Read about a demo fusor which many here first build. It is a good first step. Good luck.

Re: Gaining some energy back from our fusion reactors

Posted: Tue Jul 07, 2020 12:16 am
by Erich Gazenko
Thank you Dennis. I'll try to build a fusor. The next time I will ever post on this site is when I have built one. I promise I won't fade away.

Re: Gaining some energy back from our fusion reactors

Posted: Tue Jul 07, 2020 7:04 am
by Richard Hull
Not posting on your effort until finished is kind of silly. You should learn and share your progress as you go. That is what this site is all about.

Richard Hull