Search found 2516 matches

by Chris Bradley
Wed Sep 03, 2014 10:39 pm
Forum: Vacuum Technology (& FAQs)
Topic: Cleaning the Chamber 2
Replies: 8
Views: 3144

Re: Cleaning the Chamber 2

It is generally best to know what the contaminations are before you attempt to clean it. But the advantage of an ultrasonic bath is that whatever much is there is dislodged by a physical (mechanical) action rather than a chemical one. A bath of the right solvent to solvate the specific contamination...
by Chris Bradley
Wed Sep 03, 2014 8:07 pm
Forum: Ion Gun Design and Construction (& FAQs)
Topic: Small neutron source
Replies: 29
Views: 14124

Re: Small neutron source

Thomas, as I am sure you already know, a conventional CW multiplier does not provide equal current at each node (thus unequal acceleration voltage).

If you would like to improve that then you might like to take a look at an invention of mine:
viewtopic.php?f=11&t=4887
by Chris Bradley
Wed Sep 03, 2014 5:36 pm
Forum: Ion Gun Design and Construction (& FAQs)
Topic: Small neutron source
Replies: 29
Views: 14124

Re: Small neutron source

But I think with the most probably D-D reaction D + D > n + He3 there no proton emitted, the second reaction chanel with much lower probability D + D > p + H3 a proton would be emitted. Those two routes are approximately (not quite) equal. It is the D+D->4He + hv reaction that is rare, about 1/2000...
by Chris Bradley
Wed Sep 03, 2014 4:57 pm
Forum: Vacuum Technology (& FAQs)
Topic: Cleaning the Chamber 2
Replies: 8
Views: 3144

Re: Cleaning the Chamber 2

I'd recommend seeing if you could find someone with an ultrasonic bath. If they have a good one then they will likely have access to an appropriate solvent to bath it in. Be cautious about any deposits on vacuum stuff that you don't know what it is. Lots of vacuum parts are used with toxic processin...
by Chris Bradley
Wed Sep 03, 2014 4:50 pm
Forum: Vacuum Technology (& FAQs)
Topic: Sourcing Vacuum Hose
Replies: 9
Views: 3355

Re: Sourcing Vacuum Hose

Wire-reinforced PVC hose, 1/2" ID, is still a penny a foot Stiff is not so good. I'd promote Richard's point - vibrations from a direct drive vacuum pump are not what you want to transmit, especially to a turbo pump or similar. I use a long piece of NW16 flexi, but that reduces pumping speed (thoug...
by Chris Bradley
Wed Sep 03, 2014 4:44 pm
Forum: Vacuum Technology (& FAQs)
Topic: Silicosis From Boiling Diff. Oil and Mech. Pump
Replies: 9
Views: 3162

Re: Silicosis From Boiling Diff. Oil and Mech. Pump

Yup. Ditto. Water hose. Actually belt and braces - both an oil mist filter and I pipe it to the outside.
by Chris Bradley
Fri Aug 29, 2014 3:33 pm
Forum: Vacuum Technology (& FAQs)
Topic: Venturi as a roughing pump?
Replies: 1
Views: 990

Re: Venturi as a roughing pump?

jkelleyrtp wrote: if I need to get even lower to achieve a rough pressure
Yes. Just over 3 orders of magnitude better vacuum, call it 4, before it can back a molecular pump.
by Chris Bradley
Fri Aug 29, 2014 3:32 pm
Forum: Ion Gun Design and Construction (& FAQs)
Topic: Small neutron source
Replies: 29
Views: 14124

Re: Small neutron source

It might just be sputtered material from the wire, as these work by a continuous corona generation. Yes, I bought a pile of these too and wondered what I had wasted my money on! After 10's of hours of effort, decided they didn't work. Some months later looked again once I had access to an oscillosco...
by Chris Bradley
Thu Aug 28, 2014 5:11 pm
Forum: Vacuum Technology (& FAQs)
Topic: Cleaning the Chamber
Replies: 11
Views: 4735

Re: Cleaning the Chamber

Acetone attacks a surprisingly large range of materials. Unless you have heavy oily contamination, I'd personally say you should stick with IPA.
by Chris Bradley
Wed Aug 27, 2014 8:08 pm
Forum: Vacuum Technology (& FAQs)
Topic: Cleaning the Chamber
Replies: 11
Views: 4735

Re: Cleaning the Chamber

just today i realized you should not touch CF flanges with your bare hands because their is a risk of oil contanimation from your skin It's really a bit OTT at this amateur level. A polish-up with a clean lint free cloth will be fine. Any volatile residues remaining will not take long to pump off. ...