Farnsworth Fusor

[sparkyman400]

interesting toy but what is the purpose of this? Can it produce electrical power in some way?

[Fusiontron]

@sparkyman400 Not in a meaningful way, but it can acheive fusion.

[tuseroni]

i want one just to say i have a fusion reactor in my house (omitting the fact that its a very small, very ineffectual fusion reactor)

[snedie69er]

WOURNSTRUM!

[JPINCHBECK1]

Fusion can occur at low levels and safely. You're absolutely correct. Everything depends on the plasma media, input,output. Studying the the actual moments of fusion is an instrumentation challenge at best, but there is a serious future in microreaction engineering for observing the phenomena experimentally instead of emperically through simulations. Making the reaction stable and profitable is it's own challenge. Keep at it. Check out Dr. Kulcinsky's work on He-3 if you haven't already.

[bulletproof2353]

so besides looking pretty ,are there any practical applications for this?and how much different is this from the glass plasma balls that they sell at like spencer gifts,like the ones in the goonies in the attic,and at science musems,and whats in the glass,a total vaccum or close to it,or do you put some kind of gas in there?

[Jhowson4]

@bulletproof2353 Well if I were to boost the voltage and get a better vacuum system and use deuterium and tritium gas. I would be preforming significant levels of nuclear fusion.

Plasma balls have a chamber filled with neon and argon gas and use a HF power supply. this used a DC power supply.

In this particular video I am using air (nitrogen) as my gas, but I have run it using a small lecture canister of deuterium.

[ShylannaKdV]

Erm... isn't that helluvalot dangerous to do this in a glass bell jar? The fusion produces neutrons and - under certain conditions - x-rays. Both not very healthy.

[Jhowson4]

@ShylannaKdV The pressures and voltages that i am operating at are not really optimal for x-ray or neutron production. Sure I do get some fusion to actually occur (by some I mean one to three events per second (practically nothing here in the real world)) To get the levels that are any where close to being dangerous I require at least 40Kv input, and a vacuum pressure down into the microtorr range (4 orders of magnitude below my capabilities)

[biloxipilot]

getting any neutrons? 

[ZamolxisReborn]

could you tell us your approximate vacuum pressure and voltage measurements?

just curious how much it'd cost me to build something similar....

[Jhowson4]

@ZamolxisReborn cost me about 250 bucks, but that was with borrowing a bell jar and getting a transformer and variac donated.

your other question is answered in the very beginning of the video, but here it is anyway, 

voltage between grids ~15Kv

chamber pressure ~10^-3 torr

[johnb003]

Are you using any gas, deuterium tritium, or are you just relying on the nitrogen ions left over as you suck the air out?

Have you tested to see if you're producing any neutrons?

How strong is your vacuum?

Nicely done. Are you still improving it, or is it done?

[Jerokhna]

I think if you get a decent enough magnetic field evenly distributed around the entire poissor that you might actually contain the electron stream and sustain a longer runtime. Basically a modification from the WiffeBall series of prototype reactors.

[sixpackwill1]

are there any dangers to this project other than electrocution

[everythingtechandgam]

@sixpackwill1 ya touch a loose wire and your balls get fired

[Hansolo60]

Should the vacuum pump always work?

[sparkprimeprime]

What is the trance track behind this?

[Favel22]

X rays free with your cancer order.

[dlouis95]

Whats the best way to go about constucting a Farnsworth Fusor?

[psilonox]

how many watts does that thing eat up? would it be expensive to run all the time?

[start00hh5]

plasma what is it god for ????????????

[Exarian]

Good news, everyone!

[geodesicks]

I'm sure you can heat this plasma up with microwave.

[sparkprimeprime]

i dunno about anyone else but i'm tripping balls

[yakkit]

Have you managed to put some deuterium through it yet?

[pizdiceanu]

i say that no matter how small the inner electrode is it will confine the positive nuclei.and the metalic case for better cooling,again,the trajectories are the same no matter the size.but i think will give better inner concentration.

[Jhowson4]

not necessarily, one thing to consider is how the "like" charges repel each other, if you create a poissor that is too small the charged particles will actually repel each other preventing a coherent poissor from forming. likewise if the inner grid is too large the poissor will be very diffuse and will not compress the plasma enough to form a poissor. IT took me a couple of grids to get this one close to the right size.

[pizdiceanu]

mark my words:a filament from a halogen bulb in a metallic outer case.

[Jhowson4]

This is not a halogen bulb...the filament is Tig welding wire that i bent into that shape, the outer grid is the same except i spot welded it together.

[Jhowson4]

This is not a halogen bulb...the filament is Tig welding wire that i bent into that shape, the outer grid is the same except i spot welded it together.

[lbochtler]

It looks like a red dworph star in a botel.

LOL

[yakkit]

As if this only has 8,000 views. It's my favourite video on youtube.

[Jhowson4]

Haha, Thanks for the compliment.

Spread it around to all your friends!

[halohadel]

doesnt this release alot of thermal neutrons?

[Jhowson4]

only if a get the pressure low enough, which i can not do because i do not have an oil diffusion pump or something similar. neutrons are a product of fusion, and as my fusor only really fuses ~5 atoms/second. so not much at all. With the proper pump and a tritium/deuterium gas mix that number would be drastically larger.

[halohadel]

Well once you can produce a moderate amount of neutrons, you can produce thermals neutrons and breed your own nuclear fuel

[Jhowson4]

Actually even if i could get this operating at the best possible efficiency, i do not think the neutrons produced are ever of a low enough kinetic energy to be effective at breeding fuel. I believe the Fusor is generally considered a fast neutron apparatus. But passing the neutrons it does produce through "Borated Paraffin" or another moderating material should slow them down enough to do what you are describing.

[halohadel]

I'm pretty sure that the neutrons produced are  have an Erms of 2.45 MeV... They would still work, it would just take longer. (Fast type breeder reactors work on this principle)

[Hansolo60]

The hydrogen gas is everywhere inside that vacuum chamber, but fusion occurs only in the center, correct?

[Jhowson4]

Yes, But remember that the chamber is at a very low pressure. so because of the electric field the amount of hydrogen varies with the radius, the greatest concentration being the center, where the fusion "if any" will take place.

[Hansolo60]

You pump the hydrogen in with the same vacuum pump that you use to take the air out?

P.S. This is a proton-proton reaction.

[Jhowson4]

Well, i do not have gas regulators, so i pump the chamber down to low pressure then flood it with hydrogen, or deterium(which ever i have at the time. ) once back at normal pressure i pump it down again. this ensures that the trace amounts of gas left at the lower pressure is only what i want it to be. yes it is a proton proton reaction.

[Hansolo60]

Does the positron product annihilate with the electrons in the inner grid?

[Hansolo60]

My question was - can the by-products of the reaction be used later in the process?

[teslafredde]

Did you change the pressure or did you gradually change the input power in the begining during startup?

[Jhowson4]

It says "pump down" in the description, so the pressure is decreasing the entire time. At the end I slowly decrease the power.

[Hansolo60]

For how much dollars can I build this?

[Jhowson4]

like 400$ for a cheap one like mine

[Hansolo60]

What are the materials?

[Jhowson4]

you can find detailed lists online, and i think i talk about it a while down in these comments.

[PsionNinja]

Wow, just like a mini-sun :)

[pontus515]

Its a trap!

[Jhowson4]

lol

[therealsuperhobo]

GOOD NEWS EVERYONE!

[PsionNinja]

+1 :)

[prayfertrey]

LOL!

[Jhowson4]

Some fusion does take place but it is such a small amount that for all intents and purposes it might as well be none. If I added deterium to my chamber i might get a little more fusion but even with the correct fuel, the pressure is still too high and the voltage too low. if i had an oil diffusion pump and a canister of deuterium fusion would be taking place measurably and i would either need to submerge my entire setup under a couple feet of water or get a steel vacuum chamber. to be safe.

[Tdog283]

would focus fusion create more or less energy than this type. Also, can you give me a parts list? I've been experimenting with high voltage for about 6 months, and want to attempt this.

[Jhowson4]

Honestly I have no Idea.

as for a parts list. you need a high voltage supply, vacuum chamber, vacuum pump, and tig wire to make the internal grids

[crob227]

got any hints for the internal grids?

[Jhowson4]

I use TIG wire, and i brazed it together with copper.

[Tdog283]

@Jhowson4 What type of vacuum pump did you use? Should I go for hvac, or something else?

[Jhowson4]

ideally if you want to do large amounts of fusion and plan on spending thousands of dollars you want an oil oil diffusion pump with a turbo pump. But for a little demo Fusor like this one an hvac pump will be fine. The pump used in the video cost about 200$ and is 5.5 cfm and can reach a pressure of 10 millaTorr the lower the pressure the better.

[sadmancar9]

but there should be no neutron emition right? because theres no fuel for fusion, am i right? Also wat are the dangers with radiation with fusors? im thinking of building one

thanks, good vid.

[greenboy256]

Fusors will make X-rays at high voltage and low pressure, even without fuel. When you do have fuel you're going to get neutrons (if everything works correctly) there shouldn't be too much risk unless you run it for more than a few minutes, never the less, I would recommend that you put some distance between yourself and the reactor.

[QIQrrr]

Instead of using a magnet to push/control the plasma, try experimenting with radiowaves.

[Tdog283]

Are you trying to kill him? Radio frequency energy through a vacuum sealed plasma would induce such violent vibrations that it would most likely cause the entire apparatus to explode. I've been screwing around with RF power..that's how I know, lol.

[QIQrrr]

What happened? Just a single wave or transverse waves?

[MrLordWinchester]

how did you manage the huge amount of neutrons coming out of that thing?

[nitro169]

is this a flux capacitor?

[Jhowson4]

no!

[DevilMaster]

This was interesting. Would you consider putting the plans online?

[Jhowson4]

If I had plans I would post them.

[yakkit]

Around how much did you spend on this altogether?

[Jhowson4]

not as much as you would think. I Borrowed the bell Jar from my physics teacher. I had the lexan already. payed like 10$ for a spool of tig wire. Bought 150 diodes off of ebay for 20$, the vacuum couplings and tubing were donated from a local company and the transformer was donated by a local neon sign company. The most expensive thing the vacuum pump I bought from ebay for 200$.

[yakkit]

That's pretty good. The other people I've seen doing this say they've spent $3000. I thought I could do it for much less, but the vacuum pump became a problem. It'd be practically impossible to make my own.

[jcube001]

A few of questions. What did you use for a container? What gauge wiring did you use? Can you send me a drawing of how your entire apparatus is all wired together?

[Jhowson4]

its not very complicated a 15kv neon transformer with a bridge rectifier. The inner grid gets the negative and the outer the positive. The grid is made out of tig wire and I welded it together with a torch and thin copper wire. the jar is a vacuum bell jar. its about .5" thick. don't try this with a normal bell jar it will break.

[marksda]

Have you tried using hydrogen and boron vapors?

It might be interesting to place this bright ball of light into the focal point of a parabolic mirror and line up the mirror towards a second parabolic mirror to focus it onto a second point and physically measure the power output of the bright ball of light.

[conrad2468]

how come there are no tutorials on this crap!?!?!?!

[jovicakluk]

what gas are you using

[Jhowson4]

I flooded the chamber with hydrogen but in then end it is probably just regular air. I dont have the stuff needed to regulate the gas inside the chamber. So all I can do is fill it up with what I want before i pull the vacuum.

[jovicakluk]

ohh ok so what isotope are you using, or just hydrogen

are you giving it about 50kv

[Jhowson4]

Just regular hydrogen. I bought a small lecture bottle for like 50 bucks or something.

the grid is charged by a 15kv 60ma Rectified neon transformer.

[jovicakluk]

are you serious !!!!!!!!!! i have always wnated to build one but i thought i had to have deuterium, well im gonna start working on this, the first thing im going to start making is the power supply as this is kind of my area of knowledge, then a hydrogen cell

BTW is htere any difference beetween the outside air pressure compared to inside the flask

[Jhowson4]

Well if you want to do loads of fusion you need Deuterium. But for a cool demonstration like this not MUCH fusion actually happens. probably somewhere around 5 per second or something like that.

on the inside of the Bell Jar the pressure is about 15 microns hg. Much lower than the outside air pressure. I use a HVAC vacuum pump to get it down this low. 200$ on ebay.

as for the power suppply what are you thinking of making.

[sandhirro]

If you want to do any fusion you need D2. 15keV is much to low of an energy for p+p fusion.

[Jhowson4]

This is true, and yet the neutron detector got hits when I put in near it.  Not many, but still something. Unfortunatly I had to take the device apart and return borrowed equipment. I would love to get some deterium and continue the experiments.

[sandhirro]

The most likely event is that you're using a some sort of device which amplifies a signal, and what your getting as "counts" are false because the amp is sensitive to power fluctuations in the high volt supply. However if you are detecting p+p fusion then you're breaking new grounds in physics.

[Jhowson4]

Hmmm your probably right. Since I dont think that my cheap little fusor is going to be breaking new ground anytime soon. If anything else maybe I was detecting high velocity particals that some how got through the .5" acrylic base where the detector was mounted.

[raypsi]

yes 15kilo volts is way low, really though volts is a misnomer actually it's velocity, if it weren't 4 albert e. 250,000volts would be all you need to get an electron to the velocity of light, in this neck of the woods. Once you get much higher velocity then you are going to see x-rays and high speed neutrons. And why use deuterium when tritium is so easily available? So you will get twice the neutron bag for your buck. Nothing like a few x-rays and high speed neutrons cutting a path in ur brain

[Fullperson]

you could just get hydrogen from electrolysis of water? Costs a lot less than $50 though will take more time

[Jhowson4]

That is true and i tried it in the past. But like you said it takes a while and it is much easier to handle and use if it is in a nice bottle.

[skulls90210]

Dude its lissy (again) HOW DO U DO THIS STUFF! Your cuz.

[Jhowson4]

If I knew that I would be a happy person.=)right cuz

[juavojuana]

completely amazing, i would love to tinker with one

[flybyfriendly]

jolly good show keep up the good work

[Jhowson4]

At the begining it is called a "bugle jet" and it is the plasma being forced out of the center due to the higher plasma density. Later it becomes an electron beam due the lower pressure. the electrons are being forced away from the center grid because it is positivly charged.

[elreservista]

what is the ray light?, neutrons escaping the center?