Fusion Reactor First Test Run

We are a group of students at UMass Lowell that are building a type of fusion reactor called a Farnsworth Fusor.

Fusion has been conventionally done by heating a gas to such a high temperature that the average particle of gas has enough energy to overcome the coulombic repulsion of another particles nucleus so that it can fuse.

Instead we use 2 concentric spherical grids one of which is at a high negative potential to produce an electric field that accelerates the ionized gas to high enough velocities to fuse. The associated technology and cost of operations is many times less that the big budget fusion projects like ITER, while still producing a continuous nuclear fusion reaction.

The system consists of a vacuum system which evacuates our stainless steel vessel. We then use a variable autotransformer to control an input voltage for our high-voltage transformer. The transformer supplies anywhere from negative 10,000 to 50,000 volts to our central grid.

This video highlights our first plasma achieved. No fusion is actually ocurring in this video as the chamber is filled with air at medium vacuum pressure. To actually produce fusion reactions we will fill the chamber with it's fuel, deuterium gas.

Category:

Science & Technology

Tags:

• fusion
• reactor
• fission
• deuterium
• nuclear
• atomic
• farnsworth
• hirsch
• meeks
• fusor
• high
• voltage
• plasma
• physics
• vacuum

[applrichardbyl]

naive.. the gas atom is too loose to be able to fuse. what you saw was just kind of plasma. the energy you got was far from the level to "ignite" the nuclear reaction. I think you at first should calculate the energy to fuse a pair of deuterium, then you will know how much energy at least needed to conduct the experiment.

[userjjb]

@applrichardbyl I think *you* at first should calculate the energy to fuse a pair of deuterium. Accounting for coulombic repulsion of nuceli, adjusting for a Maxwell–Boltzmann distribution and quantum tunneling at distances close enough for the strong-nuclear force to act you need ~4x10^8 Kelvin. This might seem like a lot until you realize that 1eV=1.2x10^4 Kelvin according to kinetic theory. So ~35keV is enough to fuse. We really only need half that voltage since both ions are accelerated,

[cowsrock94]

How do you create negative voltage?

[userjjb]

@cowsrock94 We use a variac to from mains voltage input into a small step-up transformer (~150x if I remember correctly) that brings us up to ~20 kV AC. Next is a full-wave bridge rectifier using some HV diodes to get HV DC, keeping only the negative portion of the AC sine wave. In many applications you'd add a capacitor to filter out noise and smooth distortions from the rectification; The fusor is a large enough capacitive load that we can avoid one along with the danger of the stored energy.

[cowsrock94]

@userjjb Well that clears things up :P

I'm happy i can understand all that, maybe I'll make my own fusion reactor.

Where can I get deuterium?

[userjjb]

@cowsrock94 Most chemical supply houses sell "lecture bottles" of deuterium. These are small pressurized cylinders of deuterium typically for use in small demonstrations, labs, etc.

[BornAgainEngineer]

Good news everyone... i've built a Farnsworth fusor

[userjjb]

@rayreckless Near Boston, Massachusetts in the US. I didn't specify my exact geographical location because it isn't relevant to the video, a quick google search would let you know if you really cared. People don't typically specify a particular country when they mention where they go to school. Thanks for the presumed passive-aggressive condescension though.

[nanotektor]

I think you can use this plasma chamber to create carbon nanostructures, just at a microwave source inside, an organic vapour source, and you get them...

[StinkyPheet]

When the hell is this shit going to finally be useful? I need a super star destoyer NOW not 100 years from now.

[Zvesda]

@magicks934

It's a big nightlight.

[magicks934]

What the hell does it do???????????



[TheRottenburger]

so how long till you can send me back in time