Search found 211 matches

by Jeroen Vriesman
Mon Jun 27, 2016 11:39 am
Forum: Fusor and/or General Fusion Theory (& FAQs)
Topic: "internal helium leak" may suggest Li-6 + Li-6 fusion!
Replies: 8
Views: 5603

Re: "internal helium leak" may suggest Li-6 + Li-6 fusion!

...."and a separate turbo for the RGA".... That's not needed, I use a big valve between the turbo and the chamber, which is open during pump-down and bake-out, then the valve is closed, but it's bypassed with a throttle valve, so the pressure in the chamber can be medium vacuum, while the turbo crea...
by Jeroen Vriesman
Sat Jun 04, 2016 9:26 am
Forum: Vacuum Technology (& FAQs)
Topic: How to measure the temperature of tungsten wire?
Replies: 15
Views: 6869

Re: How to measure the temperature of tungsten wire?

Thank you Roberto! (and the rest). One question, benzene or toluene is used as the hydrocarbon for carburization, both are a bit toxic. Is there any reason why something like butane would not work? The temperature seems high enough to break down any hydrocarbon. Or is does the reaction require doubl...
by Jeroen Vriesman
Wed Jun 01, 2016 11:34 am
Forum: Vacuum Technology (& FAQs)
Topic: How to measure the temperature of tungsten wire?
Replies: 15
Views: 6869

Re: How to measure the temperature of tungsten wire?

Hi Preston, activation by measuring the emission at high temperature is not working, when the wire gets hotter, there is a huge increase in emission, but that drops within about 20 seconds because the Th evaporates. Ideally the operation temperature is where the diffusion of the Th is enough to comp...
by Jeroen Vriesman
Tue May 31, 2016 8:56 am
Forum: Vacuum Technology (& FAQs)
Topic: How to measure the temperature of tungsten wire?
Replies: 15
Views: 6869

How to measure the temperature of tungsten wire?

Any ideas on how to measure the temperature of a glowing Th-tungsten wire without buying expensive equipment?
For activation I need to know when certain fixed temperatures are reached ( 2800, 2200 and 2000 K ).

How (un)reliable is the resistance as a temperature indication?
by Jeroen Vriesman
Tue May 17, 2016 5:44 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: ZVS Driver, Intermittent Operation Question
Replies: 2
Views: 2827

Re: ZVS Driver, Intermittent Operation Question

Two things to check: I cannot see it clearly on the picture, but maybe your 470 ohm resistor is 4700 ohm? (third ring red?) But more likely: your 13.8v power supply might have a high impedance for high frequencies. So try to put a good capacitor (low impedance, high frequency, high current) over the...
by Jeroen Vriesman
Wed Feb 17, 2016 10:09 am
Forum: Vacuum Technology (& FAQs)
Topic: Best gas for plasma cleaning?
Replies: 7
Views: 3565

Re: Best gas for plasma cleaning?

Thanks for the comments. I will try with argon.

picture of the plasma cleaning with air of the KF chamber, and a picture of the CF chamber I want to clean. I cannot do a plasma cleaning on the rga and valves under the chamber left, so I will have to heat that part of the setup.
by Jeroen Vriesman
Tue Feb 16, 2016 2:22 pm
Forum: Vacuum Technology (& FAQs)
Topic: Best gas for plasma cleaning?
Replies: 7
Views: 3565

Best gas for plasma cleaning?

I had a KF 100 cross, with a lot of sputtered copper and other contamination. Tried to fix that with iron chloride. This worked for the copper, but now there was some other unknown black stuff, which was cleaned with hot nitric acid and other aggressive chemicals. So far so good, but there was a lot...
by Jeroen Vriesman
Sat Feb 06, 2016 8:09 pm
Forum: Ion Gun Design and Construction (& FAQs)
Topic: Linear deuterium Accelerator-Ion Gun Issue
Replies: 50
Views: 38880

Re: Linear deuterium Accelerator-Ion Gun Issue

How could this produce a "narrow beam of neutrons" ? The neutron energy is much higher than the initial deuteron energy, so with beam on target you still have neutrons going in every direction? Or am I missing something? If you do need more current, you might try to build a Felici generator. http://...
by Jeroen Vriesman
Sun Jan 31, 2016 6:46 pm
Forum: Vacuum Technology (& FAQs)
Topic: Safely Evacuate a CRT
Replies: 12
Views: 6507

Re: Safely Evacuate a CRT

Bob, isn't the carburization process creating a tungsten-carbide layer to minimize evaporation of the filament? This text: http://electrontubestore.com/thoriated-tungsten.pdf mentions the metallic thorium forming a mono-atomic dipole layer on the surface, the thorium coming from reduction (where is ...
by Jeroen Vriesman
Tue Jan 26, 2016 11:50 am
Forum: Vacuum Technology (& FAQs)
Topic: Small and simple mass-spectrometer
Replies: 8
Views: 7700

Re: Small and simple mass-spectrometer

Thomas, within about three weeks I will have 5 sizes of 2% thoriated tungsten wire, 0.05, 0.1, 0.15, 0.2 and 0.25 mm. I will probably make some sets with all the sizes and put them on the trading post here, it's not about making profit so the price will be lower than anything you can find on ebay, b...