Search found 426 matches

by ian_krase
Sun Dec 15, 2019 2:36 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Making Large Vacuum Chambers
Replies: 6
Views: 192

Re: Making Large Vacuum Chambers

Who's S and S?
by ian_krase
Sun Dec 15, 2019 2:12 am
Forum: Items wanted
Topic: Wanted: Welding Services
Replies: 0
Views: 12

Wanted: Welding Services

Is there anybody in the San Fransisco Bay / Silicon Valley area who can do TIG welding?

I pulled a welded bolt-stud partway through my baseplate and need it welded back vacuum tight.
by ian_krase
Sat Dec 14, 2019 9:03 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Making Large Vacuum Chambers
Replies: 6
Views: 192

Re: Making Large Vacuum Chambers

Interesting. This makes me somewhat more optimistic -- one could substitute a heavy metal plate for the acrylic, and machine a conflat into it.
by ian_krase
Sat Dec 14, 2019 9:01 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Efficient way to bombard target with electrons in the 50-100 eV range? (not for fusor)
Replies: 20
Views: 556

Re: Efficient way to bombard target with electrons in the 50-100 eV range? (not for fusor)

I will only put current through the filament under vacuum (e.g. 1x10^-4 Torr). Will the filament be poisoned at atmospheric pressure in air even if there is no current through it? If you're using pure tungsten filaments, they will not be poisoned by air at any time whatsoever, but they will *burn o...
by ian_krase
Fri Dec 13, 2019 7:31 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Making Large Vacuum Chambers
Replies: 6
Views: 192

Re: Making Large Vacuum Chambers

As is often the case, I'm not interested in specifically building a fusor. Though my requirements for hermeticity are arguably higher. Meanwhile I have my own apprehension because the chamber types I am looking at still cost enough to not want to dive in blind (at the very least, would need to pay t...
by ian_krase
Fri Dec 13, 2019 7:27 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Efficient way to bombard target with electrons in the 50-100 eV range? (not for fusor)
Replies: 20
Views: 556

Re: Efficient way to bombard target with electrons in the 50-100 eV range? (not for fusor)

Ion beam sputtering? Sounds interesting -- and like something to try if I ever get a bigger chamber. If I was doing this, I would put the filament at ground potential and drive the target positive, assuming I have three feedthroughs. Makes the filament heater supply easier. I don't use SEM filaments...
by ian_krase
Fri Dec 13, 2019 7:24 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Fusor V Chamber
Replies: 20
Views: 5356

Re: Fusor V Chamber

Outgassing -- because it's huge and has lots of internal surface area?

That is quite gigantic. Needs a big viewport door.
by ian_krase
Thu Dec 12, 2019 5:21 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Making Large Vacuum Chambers
Replies: 6
Views: 192

Making Large Vacuum Chambers

Pipe tee fusors are all the rage nowadays, which is good because they are inexpensive to make without welding. But sometimes, we want much larger chambers. Which typically are at least hundreds of dollars even used on Ebay. Does anybody here have experience using pressure cookers, pressure pots, or ...
by ian_krase
Thu Dec 12, 2019 5:08 am
Forum: Items wanted
Topic: 60 kV Cable, any gauge
Replies: 7
Views: 147

Re: 60 kV Cable, any gauge

Interestingly, I have never actually encountered high-high voltage silicone insulated HV wire. What I have is insulated with... some kind of rubbery polyolefin.
by ian_krase
Wed Dec 11, 2019 6:03 am
Forum: Items wanted
Topic: 60 kV Cable, any gauge
Replies: 7
Views: 147

Re: 60 kV Cable, any gauge

Personally I would only use RG-213 with extreme high voltage, and never any cable with a foamed interior.

Also it is worth noting that for extreme high voltage, Spellman actually uses a high-voltage-rated version of RG-213.