Search found 464 matches

by ian_krase
Fri Nov 30, 2018 9:01 am
Forum: Ion Gun Design and Construction (& FAQs)
Topic: Electron Impact Ion Source pictures wanted
Replies: 3
Views: 467

Re: Electron Impact Ion Source pictures wanted

I have gotten so far as to pick up on the "box" structure of these ion sources. I'm curious whether you have a clear idea of how the gas is injected -- is there just a tube going into the side of the ion box? How large would you say the exit and entry holes typically are? Are they equal to each other?
by ian_krase
Mon Nov 26, 2018 6:48 am
Forum: Ion Gun Design and Construction (& FAQs)
Topic: Electron Impact Ion Source pictures wanted
Replies: 3
Views: 467

Electron Impact Ion Source pictures wanted

I'm interested in any pictures or diagrams that anybody has of professionally made or mass produced electron impact ion guns.

(these are more common in RGAs and mass spectrometers, which is what I am building, than in things like fusors.)
by ian_krase
Sun Nov 25, 2018 5:14 am
Forum: Advanced Technical Discussion Area
Topic: Harbor Freight freebie meters
Replies: 12
Views: 949

Re: Harbor Freight freebie meters

I'm not sure if the meter ratings should be Considered ridiculous safety nerd stuff. I'm not willing to use HF meters, or most other cheapie meters, on moderate-voltage high-current stuff like wall current.
by ian_krase
Thu Nov 22, 2018 5:45 am
Forum: Advanced Technical Discussion Area
Topic: Harbor Freight freebie meters
Replies: 12
Views: 949

Re: Harbor Freight freebie meters

Ahhh, yes.

Then of course there are the Keithley vacuum tube frontend electrometers, with input impedance measurable only in scientific notation.
by ian_krase
Tue Nov 13, 2018 6:39 am
Forum: New User Chat Area
Topic: Interested in talking to an expert chemist for non-fusion question
Replies: 0
Views: 148

Interested in talking to an expert chemist for non-fusion question

I'm interested in talking with an expert chemist for a question/project unrelated to fusion. It concerns combustion and organic chemistry.
by ian_krase
Tue Nov 13, 2018 6:22 am
Forum: New User Chat Area
Topic: Crystal synthesis inside a vacuum?
Replies: 3
Views: 307

Re: Crystal synthesis inside a vacuum?

I believe that sputtering sometimes forms crystals as well, at least when the substrate is a crystal.
by ian_krase
Tue Nov 13, 2018 6:20 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: My progress II
Replies: 20
Views: 1749

Re: My progress II

I would like to add that one can often "chop-shop" tees and crosses together using an inexpensive Mapp Gas blowtorch and silver brazing compound. There are lots of cheap vacuum components on Ebay that were made for some specific machine. To the casual user, they are of little use, very strangely sha...
by ian_krase
Tue Nov 13, 2018 6:12 am
Forum: New User Chat Area
Topic: Vacuum chamber parts
Replies: 3
Views: 288

Re: Vacuum chamber parts

Yes, glass bell jars or cylinders of any kind are just risky even for demo fusors -- too easy to heat up to a hot spot, crack, shatter, and implode.

A better idea is a tee or cross, plus flat glass viewports -- *much* less expensive, and much less dangerous if it breaks.
by ian_krase
Tue Nov 13, 2018 2:10 am
Forum: Vacuum Technology (& FAQs)
Topic: Advice on locating reason for poor vacuum?
Replies: 4
Views: 917

Re: Advice on locating reason for poor vacuum?

To clarify a bit: this is about locating virtual leaks, slow permeation, and outgassing, not true leaks.

Detergent... why not toluene?
by ian_krase
Mon Nov 12, 2018 10:09 am
Forum: Vacuum Technology (& FAQs)
Topic: Advice on locating reason for poor vacuum?
Replies: 4
Views: 917

Advice on locating reason for poor vacuum?

I've been trying to get to 10E-6 with my vacuum system, but having a hard time breaking 3E-5. As far as I can tell (via leak testing with a trace gas) my system is airtight. However I suspect it's dirty (I'm a slob) and/or contaminated by my questionable vacuum grease decisions. Does anybody have a ...