Caden Burkhardt-Fusor Progress

[Dennis P Brown]

John is correct. Also, sharp edges on bolts start to allow serious corona discharge problems - for now, however, that isn't a big concern. More of a FYIO.

Good start on your vacuum system. Though a real vacuum gauge will give you a better idea on the pump and system's overall performace.

Certainly, getting your first plasma discharge is a good goal.

[caden_Burkhardt]

ok, thanks for pointing that out

[Rich Feldman]

Looking good there.

I bet your "NST" is a high frequency power supply, which is warned against in FAQs here.
* When it's off, what's the DC resistance between the two high voltage output wires? Can you measure a DC resistance between those wires and a metal part of the case (if any) or the ground pin of power plug (if any)?
* Another way to get a clue: what's the weight?
* A third way: connect it back up to light the neon sign. (Any subset of intact glass elements. Or you can safely drive any ordinary fluorescent lamp or CFL tube directly.) In an otherwise dark room, it should be easy to see stroboscopic effects if the brightness is fluctuating at 120 Hz. Just wiggle your finger in front of your eyes, or look at a spinning fan or motor shaft.
* Fourth way: look up the model number on the Internet. I just did & found the answer within a minute.

If you have a high frequency power supply, I bet you can still light up a demo fusor, it'll just take a bit more work. Microwave oven diodes might be too slow to serve as good rectifiers.
Another surmountable hurdle is the Secondary Ground Fault Protection which appears on the label in one of your pictures.

[John Futter]

Rich
I didn't see that it was a high freq unit
you can get high frequency HV diodes out of dead panasonic inverter microwaves they usually blow the igbt

[caden_Burkhardt]

It would seem I leaped before I looked . . .
However the NST was only a $10 investment, better to fix my problems now that be bewildered later

[caden_Burkhardt]

8/3- bought a NST(12kv, 60mA and began wiring it up

8/4- did a lot of work with my electrical system, including remounting everything in a plastic container, as per john's advice


8/11- After taking a break for a week, I finished wiring my electrical system. I put wire nuts on the exposed bolts as per Dennis's advice, and my HV system was ready. I hooked everything up and fired up the sytem. While putting a grape wont get me into the plasma club I hope this will. My first run I cranked the variac to the max and ended up blowing a fuse. My second run I didn't turn the input voltage over 80 volts. One thing to note is that I didn't really run my vacuum system for that long before applying voltage. I waited one minute on the first run, and ten on my second.

My setup

Plasma

Plasma

This is by no means the end of my journy I hope to order some metering equipment and a TC guage soon so I can get measurements on my system

[Richard Hull]

Good work on first plasma, Caden. You can be in the plasma club once you have instrumentation. (update 8/20/20)

Richard Hull

[Dennis P Brown]

Agreed - good start and congratulations on the 'Plasma Club'. Your aim to get the vacuum system better qualified via a proper vacuum gauge is a good and necessary goal.

Of course, a better support system for the fusor chamber should also be a top issue.

In the future, even if you get a proper fusor supply, NST's are very useful - they are a great way to test high voltage (HV) diodes and meters and being fairly safe are ideal for these purposes. Speaking of HV systems, in the furtue, don't cross HV lines like you have in the pic. Keeping HV lines well apart - even under oil - is both a good and safe pratice.

As you are likely aware, you also need to address a proper pump port/line for the fusor; that tiny line is fine for the plasma club but will really interfere with pumping your chamber. However, that is perfect for use as a deuterium feed line (which, I guess, is its real future purpose.)

Not sure of your HV lines - I see only co-ax cables in the pic but if that is what you are using for HV, you need to replace those ASAP and get proper HV lines: for a quick fix, the local auto stores have HV lines good to 20 kV and would work well for a NST. Of course, you could order proper higher current and voltage (30/40 kV) line from companies/ebay.

[Bob Reite]

Actually RG-8 Coax cable is good to 60 KV DC. One does have to prepare the ends carefully.

[caden_Burkhardt]

Thank you Dennis for your input and advice. I'm not actually using co-ax cables in my system, I'm using some 8 gauge copper wire that I acquired from my dad's work. They were throwing it out after a project so it's what was available.

The same is true with my vacuum line, just leftovers from my dad's work.

I plan on replacing all my HV lines with properly rated Hv lines soon and I'll uncross those lines ASAP

[caden_Burkhardt]

8/31/20- bought TC gauge and readout

[Robert Virkus]

Hello Caden,

You have probably thought through all the safety issues but if you have not, please make sure you don't accidentally generate some dangerous X-rays!

Thanks,

Robert

[Dennis P Brown]

As for x-rays, as Richard points out - distance is one's friend when the fusor is running.

[John Futter]

Robert
While we are at it
could you please edit your profile so that you are Robert Virkus as the rules state not just Robert
Thank you

[Robert Virkus]

I was doing an X-ray experiment while a student in physics and I was deeply engrossed in thought and I just walked right around the shielding like an idiot right up to the device without thinking when it was full on so I know it's possible to defeat safety protocols.

[Dennis P Brown]

Running a fusor at home requires essentially zero margin for error when it comes to high voltage; sure, the x-ray radiation is dangerous (and need not be with careful design) but a short exposure is highly unlikely to cause long term health issues, much less death. Not so with the power supply - one mistake and death is instantaneous. Rethink doing this if you feel that you cannot follow strict procedures without failure.

[caden_Burkhardt]

9/5/20-Tc gauge readout arrive-analog with two set points
9/11/20- Tc gauge arrived
9/13/20- Hooked up the tc gauge to my chamber and ran a preliminary vacuum test. I got my chamber down to 100 mTorr

I'm yet to do a plasma run with my new vacuum gauge but I hope to do so, record the data and compare it to the visual vacuum gauge FAQ

[Dennis P Brown]

Is your chamber only reaching 100 microns or is that the gauge giving an inaccurate reading? Try the gauge just on the pump head and that will tell you: first, if the gauge is likely accurate; second, whether your chamber is leaking or not.