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Fusion test run- without fusion.... (weired light effects..)

Posted: Sat Nov 22, 2008 9:43 pm
by myID
Oh... waiting for Deuterium...

Today I did a test run at what I guess are fusion like conditions. I cranked up to a voltage of 40kV at a a current of 7mA (300W Halogen Xfmr as primary ballast plus big water resistor on HV side). Vacuum pressure was approx. 3x 10e-3 mbar- then my scintillator went chirping away- I do not know if for xrays or for catching noise but I decided to quit there.
I still did not connect my HC cable directly because I do not want to soak it in oil so far- so I also had a lot of ozone and spray...
Pressure can be regulated really nicely with the needle valve I have but I guess I have quite a big gasflow. The oil insulated feedthrough works great- in fact I think everything works quite good- we ll see if the Neutrons also think so
For monitoring the plasma I used my new Philips SPC620NC web cam- seems to be not too bad because you can even see a very faint glow but seeing grid is red hot is kind of hard.... I had a really nice star but at that point I did not know how to capture images The images I got later have some sort of glow from the ebeams hitting the glass. (btw. I shielded the view port with 3mm lead behind the cam)
I attached pictures of the complete setup and also a crappy one of the glass- glow.
On the setup picture you can see that I wrapped some plastic foil around the feedthrough- just be safe in case of oil leaks. On the left on the green box is one of my scintillator probes. The lead shielding in front of the camera is clearly visible. Left side of picture is my variac, in the background the HV tank. Right side HV monitoring, in the front the needle valve. Under the table: Turbo pump, Fore pump, right side: water heat exchanger for cooling the Turbo. Ah- and the small black thing on the cable in front is a little remote/ safety switch that controls a BIG relays that switches both contacts of the mains for the HV xfmr when you let the switch go- ground always keeps connected! (Kind of "dead man safety")
The whitish stripes on the other picture are from the particles hitting the glass.

Have a nice weekend

Re: Fusion test run- without fusion.... (weired light effects..)

Posted: Sun Nov 23, 2008 12:21 am
by Carl Willis
Hi Roman,

Congrats on "first light." You definitely have fusion-ready specs on your vacuum system and high voltage. The blue discharge, if the color is reproduced faithfully here, seems to indicate hydrocarbon contamination. Oils, solvents, or something burning inside often result in a striking bluish cathode glow.

Good luck the rest of the weekend, and hope you can get some D2 in there soon.


Re: Fusion test run- without fusion.... (weired light effects..)

Posted: Sun Nov 23, 2008 12:34 am
by Steven Sesselmann

Congratulations on a nice looking setup!

Tell me more about the white stripes on the glass, why are particles hitting the class in this way?

PS: At 40 kv it is quite likely that you are getting some X rays leaking out somewhere, you should get a sheet of lead from the hardware store to put in front of the reactor, and also eliminate any corona from the HV circuit. Filling oil in the top of your feedthrough will no doubt help.


Re: Fusion test run- without fusion.... (weired light effects..)

Posted: Mon Nov 24, 2008 12:48 pm
by UG!
Great to see your making good use of that chamber!

Keep up the good work


Re: Fusion test run- without fusion.... (weired light effects..)

Posted: Tue Nov 25, 2008 12:06 am
by myID

thanks for the comments. The feedthrough is oil filled- still the HV cable is connected outside the oil to the HV meter and the water resistor- this is where the corona leaks are... I want to get rid of the water resistor and with it with the HV spray- HV cable will be connected under oil then... The white stripes appear (I guess) where the electron beams hit the inner protective glass in front my viewport. Stripes because my grid does not have equatorial rings. Usually I would expect the glass to glow green- perhaps it is the type of glass, perhaps it is my camera- I do not feel like looking at it directly