Sorry for the quality of the renders, but I have attached the STEP file if anyone wants to see it more detailed in a CAD software.
So in theory, my system would consist of a chamber made up of a KF50 to KF16 reducing tee, which would have a brazed KF25 nipple for the viewport. The vacuum system would consist of a diffusion pump (which has been very difficult to source at eBay) connected to a machined adapter to a KF16 nipple, which would be connected to a KF16 right angle bellows valve connected to a KF16 tee which would house my vacuum transducer (MKS901p) and then the final connection to the KF16 of the chamber. The chamber electrical connection will be made by a KF50 compression fitting, similar to Liam David's DIY feedthrough. While not in the CAD, there will be a Swagelok fitting (1/4"?) for the gas supply. Finally, I will blank the remaining KF50 port, though I put a viewport in the CAD just for the sake of it.
What I am worried about are basically these things: (but if anyone sees another problem go ahead and please point it out)
- Brazing: I've talked with some members, and they assure me that brazing small KF fitting isn't difficult with some practice and can get me leak-free joints. I am planning on just brazing the KF25 half nipple for the viewport, is it a good idea?
- Viewport: I am also planning to save some money in the viewport, so instead of buying a $100 viewport, I am thinking of using a KF25 bored weld flange ( https://www.ldsvacuumshopper.com/1boresize.html ) and then using some epoxy or JB weld to place a 1" disc of borosilicate glass.
- Feedthrough: the design I am after is the one Liam David made for his fusor, but I am worried that it may be overkill/overpriced because alumina tubes are expensive, could a spark plug or a glass disc feedthrough work for fusing levels of HV (+30 kV)?
Here are some cutaway images of the feedthrough:
/Credit for these pictures goes to Liam David, thanks for the help!
- Diffusion Pump: Finally, I've been having problems looking for some equipment, and looking for a well priced diffusion pump has been a problem. I've been thinking of even going the DIY route, but if anyone has a recommendation here it will be greatly appreciated.