Could someone please mentor and assist me to build a fusor (Bay Area)

[pfactorial]

Hi!

I'm really looking forward to build a fusor. I am a high schooler, but really enjoy physics (especially Richard Feynman, even though love for him is now a cliché). As said in the title, I live in Fremont, California and am currently looking to build a demo fusor, then a larger fusor later on in life.

So could anyone with experience please mentor me and help me through the process?

I would greatly appreciate all your efforts.

Thank you!
Sincerely,
Preston Z.

[Dennis P Brown]

Preston,
this is a great place to ask specific questions. Many people here are real experts in many areas (not me.) Carefully search the database here for information on fusors (basic design, required vacuum, power, gas, gauges, operation, etc.) and learn about what a fusor is and what it takes to build a simple demo unit (no fusion.) Then get an idea based on cost and difficulty what you want to do and then ask for help with specific questions.

Ask one of your science related teachers for input and possible access to equipment. Read up using the library. Read past issues of Scientific American - specifically the Amateur Scientist - they have numerous projects and details as well as a wealth of background information.

Real fusors are dangerous devices and you need to understand a lot about safety related to high voltage and x-rays.

Relative to a few specifics on support systems for fusors, I will offer a few examples:

For instance - the bases for all fusors is a vacuum system. First and foremost a vacuum pump. Specifically a two stage oil pump. These appear on ebay all the time and can, when carefully waited for, be gotten cheap (under $100 with shipping.)

Yet that does little without a vacuum gauge (like a primitive thermocouple unit) and some type of chamber; here you MUST research this site and decide what chamber would work best for your budget and abilities - some have stainless steel high vac affairs, some glass, and a few even plastic (strictly demo.) Also, the chamber must somehow be connected to the pump.

Then some type of high voltage (HV) to excite the gas (just air in the chamber at low pressure for a demo) - here any small HV or neon sign transformer will work. Learning what type of power and how to create it requires searching the database here and reading books on vacuum systems and high voltage.

A real fusor requires very high voltage/high current power supplies and deuterium gas (very difficult to acquire) and the ability to build a neutron detector (or obtain one.) Here you need to research this site and learn about neutrons and detecting them.

I have given you a number of starting points - good luck.

[pfactorial]

just asking, if there isn't deuterium gas in there somewhere, then what are you fusing?

[Dennis P Brown]

You need to understand that building a fusor that uses deuterium gas is a very difficult undertaking - also, without a neutron detector, it is pointless anyway. Deuterium gas is very hard to come by - your first effort should be to study and learn. Building a demo fusor (no deuterium and no fusion) is a difficult task but lays the groundwork to lean enough to try a real fusor. Unless you master a broad range of skills, can get all the critical equipment and put together a demo fusor, it is very unlikely you can just build a deuterium based, neutron producing fusor. Its not impossible but expensive, can be very dangerous, and needs a lot of effort. Start by learning from the many posts in the archives. Reread my first post to you and understand what I was outlining. Then decide what is best for you to start with. Trying to build the entire system at once is a lot of work. Start with the vacuum system first, and work from there.

[Jeff Robertson]

Hey Preston,

In addition to everything Dennis said, I suggest reading up on Plasma, as plasma physics is the centerpiece of the entire fusor. When you apply a high enough voltage to a gas, the molecules essentially break down into nuclei and electrons, forming a "cloud" of charged particles. As you juice up the power supply even further, the nuclei in this cloud will begin to fuse together (hence nuclear fusion). As far as I'm aware, there are no visible differences between a high energy deuterium plasma, and a deuterium plasma which is actually conducting nuclear fusion. Usually, the only difference is that the latter is at a higher voltage than the former (assuming everything else remains constant).

Air, which is composed of primarily nitrogen and oxygen, can be broken down into plasma just like any other gas.The voltage levels required to actually fuse air, however, are much higher than the amateur experimenter has access to. Regardless, it is relatively easy to create an "atmospheric plasma" which gives off the same satisfying glow as a deuterium-fusing plasma (although air and deuterium plasmas are slightly different colors). This is the main idea behind a demo fusor - you're not actually fusing, you're just creating a plasma out of the gas inside.

I've always compared this website to an encyclopedia, but with the pages out of order. All the information you need is contained in these forums, but part of the journey is digging through the archives and piecing together the bits of knowledge you need.

Unfortunately I live in LA, and I definitely am not experienced enough to qualify as a mentor. Additionally, there's not an enormous amount of frequent visitors to this site, so I don't know how many members even live close enough to you to be of use. I'd recommend talking to teachers or anyone you know who might be knowledgeable of laboratory equipment first.

You have a long journey ahead of you. Good luck!

Jeff

[Richard Hull]

I am gratified to see others contributing in assisting newbies here. The newer guys will become old boys in time and so it goes.

Make sure to constantly harp on the FAQs. Just use the search funciton in each forum that looks like its main focus is something you are curious about and just type in FAQ and hit return. The original FAQ, (the one you want), will not have a "RE:FAQ" in front of its title. After reading the original FAQ, read the replies as more info is often contained in those as well.

Read these first then you are free to ask questions.

Richard Hull

[Edward Miller]

Hi Preston, I'm in San Jose. I've been moving my lab and looking for a power supply so it will be a little while before my fusor is going. For a used/cheap chamber check out eBay or Duniway. Also check out the Bay Area Physics and Astronomy meetup group. Hopefully you have a family member or teacher that can also help.

[pfactorial]

Oh wow, thanks for replying! I have been reading the FAQs and I guess I know the basic concepts but please correct me I'm wrong:

There's an outer grid and an inner grid. The outer grid is positive, the inner grid is negative. The voltage ionizes the gas that you put inside, and the electrons shoot towards the outer grid while the ions shoot towards the inner grid. If you have deuterium, then maybe they'll collide in the middle and fuse; however, in a demo fusor, it's just ions whizzing around.

Is my interpretation correct? Is that basically all we need for a demo fusor (and later a legitimate fusor)?

Thank you in advance!
--Preston Zhou

[pfactorial]

Oh wow! San Jose is right next door to where I live. So would it be possible to work with you to build a fusor of my own? Not that I want someone to show me the whole thing; I really want to build it myself and gain the experience, I suppose

I saw your group website and I am furious at myself for missing a lecture by Stephen Hawking! Furious! Would there be another lecture or will I have to live with this for the rest of the decade? Also, where do you find out where these lectures are? I'm interested in physics (particularly particles and cosmology, I suppose. Even though I can't say that I know the fundamental basics) and really want to see Stephen Hawking. You know, I've read all his books (and especially liked the Grand Design) and to see Stephen Hawking is really high up on the list of priorities.

Thank you for helping out!

Sincerely, Preston Zhou.

[DavidStewartZink]

Preston: you're enthusiastic, which is necessary. Just don't add recklessness. Building a fusor is sort of like flying a plane, it's not really for the careless.

Your naive description of a fusor is I guess close enough, but what I would emphasize first and foremost is you learn your safety issues. For instance your electrons rushing towards the outer grid and then stopping are (a) pointed right at you, and (b) emitting x-rays from bremsstrahlung. X-rays can kill you, your neighbors, etc. etc. Should you achieve D-D fusion someday you will be—guess what—emitting neutrons. Neutrons can kill you, etc. etc. In order to ionize your gasses, you will want 100Kv+ voltages. 100Kv can kill you, etc. etc.

You could end up working with Deuterium, which is a form of Hydrogen. Hydrogen burns with an invisible flame so hot it shines mostly in the ultraviolet. Hydrogen can kill you, etc. etc.

So start by learning your safety issues, build and verify your safety equipment, then experiment. Of course the point of this site is that you can learn more quickly because other people have made plenty of mistakes.

The part you didn't mention in your naive description is all the vacuum equipment. The point of the vacuum equipment is mostly to bring down the cost of generating a plasma and gain better control over the side effects, like heat. Also, if you heat an expensive gas the thermal expansion will force you to vent most of it.

just my few cents. I haven't touched a working fusor in nearly forty years, so some of my thinking may be stale.