Construction Questions

[typhax]

Hello,

Im new to this whole thing so these questions may seem silly. I have tried to find out the answers by reading various posts but if someone could clarify that would be fantastic.

Also these questions relate to obtaining (eventually) actual fusion rather than a demo one.

Does the chamber have to be a stainless steel sphere?
- I have seen on here someone using a pressure cooker? But is that just plasma thats being produced or is it actual fusion?

Whats the best metal to make the grid from?

Whats the theory behind inserting the D2O?
i.e. Is a vacuum created,the pump turned off, then the vacuum filled with D2O? or is the pump always on etc (that may sound stupid but i really am unsure)

Is the chamber at a netural charge? or is it positively charged?

Im really sorry about how silly some of these questions will be, but it would help me get a better grasp of the whole thing if you could answer.

Thanks,

Jason

[MarkS]

Fusion has mostly been done in stainless steel vessels, though some have used copper, glass (with electron beam shielding), and I believe someone has used an aluminum chamber as well.

Grids must be constructed from a conductive metal which can handle lots of heat. Many people use steel welding wire, tungsten, and some demo models use copper. Most common metals can be used at a grid.

D2O, is deuterium oxide, also known as heavy water. Typically D2 is the preferred fuel of choice amateur because it is relatively easy to get, safe (nontoxic, non corrosive, but as flammable as normal Hydrogen). D2 can be purchased as a compressed gas in a steel lecturer bottle or made as needed via electrolysis. As for theory, the vacuum chamber is evacuated to the deepest level possible, then backfilled with D2 gas at a very small rate. The pumps continue to run, but are throttled back so as to not waste gas. The idea is to maintain a few microns in the chamber which is mostly D2, so you must balance the pumping and backfilling rates.

Chambers are kept at a neutral charge (with respect to ground) so as to not arc to objects physically near it. Chambers can be floated and charged if you are so inclined, but it tends to be a dangerous practice.

[Dan Tibbets]

If you are referring to my 'pressure cooker', then it is just a plasma glow machine (Demo Fuser). While I have improved the vacuum sealing, it has a large rubber gasket which I assume will preclude it from achiving the 'clean' enviorment needed to achieve significant fusion. As far as aluminum, I've heard that it can be used, but I'm guessing the outgassing (and ingassing?) is more problamatic compared to stainless steel.

I'm guessing that D2O (heavy water) would not work because of the 'water' present, with the ionized oxygen produced when the heavy water is ionized. I'm speaking from what I have heard from other threads, but if D2O is used, it first needs to be electrolized to isolate the Deuterium gas, and then carefully dehydrated ( remove the humidity) befor introducing it into the fuser.

My impression is that the fuser is pumped down to the best vacuum you can obtain, then back filled with the deuterium, in small continous amounts. The vacuum pumping is continued- to keep ahead of outgassing, if for no other reason. Because of this , small vacuum leaks, absorption of deuterium into the metal,and grimlens, a continous or near continous trickle of deuterium is needed. The vacuum out port is 'choked' to limit the pumping to levels that maintains the vacuum level but does not unnessisarily depleate the deuterium too fast.

While improbable, my impressions could be less than infalable...

Dan Tibbets

[typhax]

Hey thanks for the replies.

I think to save any problems in the long run that ill just try to get a stainless steel sphere. I'm in no rush so i'll hold off till i get a bargin.

Thanks again,

Jason

[Steven Sesselmann]

Jason,

Search in the various forums, for the term "FAQ", you will find a series of posts by Richard Hull, Richard is one of the pioneers and also the forum moderator.

Start reading the FAQ in Vacuum technology, then Fusor Construction, then High Voltage, then last but not least Radiation safety.

Expect that it will take you two years to learn and build a neutron producing fusor on a small budget.

Steven